Austin, Bro! This is the BEST cooling system video on the net. I have been watching vehicle repair videos for years. I have to say you are great at telling the What, Why, and How. That is what people look for when watching repair videos. None of the "this thing" or "that right there". Your explanations are simple and to the point. Your repair process is methodical, step-by-step, and detailed. Showing the tab slots for the electric fan is an example. Most vids would not show it, but you know someone out there is wanting to know what you were talking about. Very well done young man, keep it up. I will be buying an XJ for a project and will follow your channel for insight and information.
Last week it was 115 degrees here in the Phoenix valley. It was probably closer to 130-140 on the asphalt sitting in traffic. My 1999 XJ with the stock set up stayed around 210-215 while sitting in traffic. I have replaced the thermostat. E-fan and flushed the system within the last year. It all works well and the AC is always cold. If I hade the room I would have a whole field full of XJs.
I'm glad I've never experience heat like that before lol. But at that point the Jeep is doing the best it can on Cooling, it probably wasn't designed to take on that kind of heat every single day. But if I lived in that environment I would have to modify the cooling system a little bit or even add hood vents to have all that hot air escape.
OutJeeping I am conflicted about hood vents. If the engineers knew best why did it not come with vents? Having rain on the electronics seems like a bad idea. However I do see how it can help with the heat. To vent or not to vent? That is the question.
Im in Phx as well. These past two weeks I've not been driving the XJ (2000) because it runs at 210 and gets real bad heat soak when I stop at a store or something.
@Dean Bennett I only found out the hard way by thinking my electric fan was broken when the AC was on since I was used to it always being on in my older XJs.
I have a Jeep Wrangler 4.6 l Stroker. The extra power generates even more heat and it seems to be trapped in the engine compartment especially in traffic. I replaced the radiator with an aluminum 4 core radiator thinking doubling the number of cores would fix the problem of running about 205 degrees. It didn't, so I bought a louver attachment for the hood and cut out the areas of the hood under the 68 louvers which allow air to escape. The hardest part was the measuring and cutting holes in the hood to make it look like it came that way. It runs at 180 degrees everywhere now, as if the hood was off the Jeep leaving the engine compartment open. The matte black powder coating makes the hood attachment look pretty cool also.
I bought a 96 Cherokee new. Within a year I had gone up to the sierras to explore some fire roads. It was about 85 up there. As I was climbing a long upwards grade road that I would rate mild for a jeep, I noticed the temp climbing towards overheating. Was a bit surprised by that so I turned the ac off and turned the heater on and that cooled it down enough. Got to our destination,and let it idle for a bit then shut it off and opened the hood. After that on our way back all was well. But i just never got back to figuring why it got so hot since i didnt think it was working that hard. Anyways, when i went offroad i just turned the ac off. Unfortunately i got into an accident caused by the other driver that caused me to become a paraplegic. Sold the jeep to my bill. Loved that jeep and it was always offroad on the weekends. Anyway, now i have an idea what to do the next time !
Not so fun fact, the reason the XJ runs so hot is due to the 4.0 wasn't intended to be an option for the XJ. The cooling system was designed for the 2.5.
I totally agree with you. I took out my stock radiator and fan clutch and I realized that, with minimal trimming with grinder and dremel - one can fit a 18" x 18" x 3" all aluminum radiator with a 16" fan and still retain the ac condenser- which i fitted 2 smaller fans i front of the ac condenser (come on when the ac is turned on) for even more air flow. With this setup I got 170 water temp under 90 degrees. Above that it went to max of 215 in 110 degree weather. So, i cut into the hood with the large hyline vents so can't wait till next year to see if it lowers the 215 in 110 weather. I live in mostly dry desert. Prob wouldn't cut the vents in Louisiana but the vents don't really make it wetter then before. At 70 mph rain would cover the entire engine from the holes in the grille.
@@gregwendt7172stock there is no inadequacy but it is marginal. The clutch on the mechanical fan loses its ability to transfer power, the radiator starts to clog, the coolant gets old. It is also possible to have a fault such as a weakened pressure cap or leaking core plugs etc. I run all day in 40 degrees celcius and it can run fine when maintained but worn fan clutches etc can creep up on you.
@@julianlord2697 Thanks for replying. I've tested everything (fan clutch.etc.). The coolant is new and there is no leking from the block, etc. The radiator is clean and it's an aftermarket 3-row aluminum welded performance unit. The heater core was plugged but was backflushed until clean. I replaced the heater hoses and ran them away from the engine and around the fender wells. They are longer this way and allow for a slight increase in total coolant capacity. I was a mechanic for quite a few years and solved many overheating problems but nothing has worked, so far, on this jeep. the clutch fan and the electric fan work according to specs. I replaced the cap and it has the appropriate spring pressure. I'm currently shopping for a new radiator and it will be a higher capacity 4-row type. This way, I'll be able to choose the fin spacing and tube size for the best cooling. It doesn't overheat often but I want it even better.
Great video! The engineers did know what they were doing, but remember this engine bay was designed for the smaller 2.5 L and 2.8 L engines. The 4.0 L sits too high and crowds the engine bay. I have a very built-out XJ and I tow an off-road trailer. Stock cooling just doesn't cut the cake at all for me. The best improvement I made was going to a Novak single core radiator with 1.5" tubing inside, combined with 3 electric fans. I relocated the transmission cooler (away from the radiator) and added an engine cooler (also away from the radiator) and my problems are 100% solved. Even taking grades with the AC running! Thanks again for the very detailed video!
Great video. Can’t thank you enough. I found my electrical connection from fan to harness causing the fan not to come on. One of the male ends was not inserted properly into the female end, causing and improper connection. You saved me the cost of the fan and labor. Thanks buddy. Keep up the good work.
You actually want spring style clamps on radiator hoses. Because of thermal dynamics the rubber hoses and plastic radiator necks can shrink and expand depending on ambient tempatures. Spring clamp allows it to maintain the same clamping pressure as it shrinks or expands and not cause leaks.
Yes, I caught that too. The old urban myth about factory spring clamps being bad ! . .. . The other advantage of the spring clamps is that there is fully circumferential clamping.
Right! Screw-type clamps don't tighten themselves. Just as the video author says several times, the engineers knew what they were doing. The only caveat being the clamp may get tired. A tired clamp does not mean you replace it with an inferior clamp. Stick with the factory style clamps, and healthy hoses that are not all compressed where the clamps go. Hoses and clamps are inexpensive preventative maintenance.
Make sure all hoses, radiator, shroud, thermostat, radiator cap, water pump, fan clutch, and electric fan are functional and in good shape. Make sure your fluid is good, bled properly, and at the correct level. If you do all this and the engine isn't broken, you will not have cooling issues. I live in Tucson, AZ and it gets extremely hot. I drive a '92 Comanche as a daily driver and company vehicle for my business. I never have any issues cooling, even with the A/C on Max, in traffic, in the summer when it's 115° outside.
I have a '96 High Output 4.0 and solved my overheating problem with a high-performance thermostat. I also used an air grinder to grind out the interior of the water thermostat housing. That removed any sharp angles and enlarged the interior of the housing to make it smooth out the flow of coolant. My coolant temps dropped considerably...
My 1997 XJ stays around the 190-205 degree temperature, all I did was install a new radiator, new fan clutch and new thermostat with a 1/8’ hole drilled on top. Zero overheating issues even in traffic and I live in Tucson and summer temps are around 108’ and also while on the trail.
Just a note from a retired mech. When checking things as a fan as you did, it's best to check the whole system, starting at the sensor and the fuse. This way you dont get other surprises.
Very good series of videos, thanks for sharing your time on it. One small correction on the older 4.0s is from 87-88 there is a temp sender for the idiot light or gauge, depending on cluster. That grounds on the head where it’s mounted at the rear corner, driver’s side, and a single post out to the gauge/ light. There also is the temp sender, 2 wire in the block below the intake near the knock sensor that goes to the ECM. One wire is ECM sensor ground and the other is signal to ECM. In 89 they moved the ECM sender to the t-stat housing and kept the gauge/ light sender on the back of the head. These engines through 89-90 had a thermal switch in the radiator to close the electric fan circuit’s relay. With the HO from 91-95 that switch was no longer needed, as the sender in the t-stat housing allowed the ECM to calculate fueling and electric fan control with the value from a single input, whereas before the electric fan wasn’t controlled by the ECM, just a simple thermal switch. And of course 91 was the start of the open cooling system so the radiator changed to add a cap and over flow line and omitted the fan control switch. 96-01 saw changes to the ECM and possibly a couple changes to wiring but the gauge/ light sender remained in the back of the head and the ECM temp input in the t-stat housing
Most vehicles today have only a 2 row radiator core. I have had vehicles that I upgraded to a 3 or 4 row radiator core. That gave excellent results for towing and offroad. Another trick is ceramic thermal barrier coatings on the exhaust manifold or headers. My '03 Ford Explorer 4wd has ceramic coated JBA shorty headers. When I take it in for a California smog inspection. They lift the hood, and think the engine is cold. They hook up to the OBD2 port. And find the engine is warm. I plan on buying the ceramic coated headers for my '96 Jeep ZJ.
Very good work sir. I would recommend Hi-tac for gaskets. It makes installation very easy and unlike RTV it can be cleaned with solvents. Especially if you have an irregular mating surface. Plus squeeze out doesn't contaminate the system.
Did clean the inside of the cooling system on my Jeep Wrangler 4.0 with evaporust. I had a light rust problem that showed up after a flush. Cools it like an iceberg since it did it.
@ hua Thai - I never thought of this. How long did you allow the evaporust to sit in there before you flushed it? Can anyone think of a reason this wouldn’t be a good idea?
@@scottbollinger3999Empty the system out, put it in, fill it up with just regular tap water. Put the cap on the radiator and did a 200 miles road trip. It works best when hot. Flush it out immediately afterwards. Re did the flush with distilled water and anti freeze and done. Did it 3 years ago and still no problem so far. When you flush it out the water is dirty black.
@@huathai8204 it’s an iron block so that makes perfect sense. I’ve used evaporust on other things and never thought of this. I guess I’d just be afraid of it dislodging flakes or whatever and blocking passages but I guess that could happen at anytime
Wow! Did you say that red XJ had 300,000 miles? Looks very well maintained for those miles. But I suppose that is why it has 300,000 on it. Just wanted to back up ToneDeaf on the spring clamps being a better system than the worm gear ones. Great video. Well put together. Thank you!
I recently picked up a 97 Wrangler TJ. It was purchased by a friend of mine from his deceased friend to help the wife pay bills. Long story short it sat in his backyard for several years and it didn't have coolant in it just water. The clutch on the fan was working okay. When I got it it, was full of rust, full of crud. I had to flush the heater core. I ended up replacing the radiator, the water pump and I went to 160° thermostat. Now it actually will maintain temperature without overheating. But what a pain in the butt when people don't use antifreeze.
IIRC, the fan kicks on at 195. It'll also kick on if the front temp sensor is disconnected. You can also get rid of the diaper under the engine, which is probably a oil-soaked fire hazard by now.
Agree with everything you said. Tried the CSF 3 row and it didn't cool any better. Sprung a leak after 2 or 3 years and I replaced it with stock style. ZJ fan clutch was the best upgrade I've done to keep it cool. I used a flowkooler water pump and had no problems for 10 years or so. Parts store pumps just didn't hold up.
I find having the auxiliary fan on a manual switch and a little lower temp thermostat for the summer works well. Still stays about 195 with the ac on in a 100 degree day. I just switch back to a higher thermostat in the winter. I do have a little more capacity in my radiator than stock. Heat wrapping the headers down to the y pipe is also a good modification. Helps limit heat soak and keeps the trans and transfercase a bit cooler. Later 4.0's had a heat shield under the fuel rail which you can use in any older 4.0. Just be careful not to let it run too cool though.
manual elec fan switch, 180 therm and took off heat shield junk for better airflow around manifold side......let fan run minute or two b4 /after running on hot days or sitting in traffic or drive thru works great
I have a 98 XJ with, as of today, 307,002 miles on it and I have had it as my daily driver for over 3 yrs and it hasn't over heated once. And it's sad to say that I have never changed or flushed out the coolant system nor have I added any anti-freeze I also would not be surprised to find out that it's probably the original transmission fluid 4.0 straight-6 rules! JS LOL
Super informative video. I'm redoing the entire cooling system on my 97 xj. The guy before me used some of the worst aftermarket parts I've ever seen. This was a great run through. Thanks brother
@@luisbarraza9709 I went to O'Reilly's and bought 36amp cooling fan it wasn't specifically for a Jeep I just wanted something with some power and I just hardwired it directly in fortunately for me there was already a 40 amp fuse under the hood in the fuse box so it worked out pretty good.
I live in Texas ,auto transmission sucks and heats up rad temps so I slapped a bnm with temp sensor transmission stays under 200° out of the torque converter , but in cold temps cardboard on the grill is my fix lol
I have 2 cherokee sports with 4.0 and a 318 gr cherokee limited. I flush the engines as the cast iron blocks rust a lot inside. on the 2001 i used 911 rust dissolver in the motor. It mixes with water and i let it sit for weeks starting occasionally. It removes most of the rust. New 3 core aluminum racing radiators for about 110$ New aftermarket water pumps, 50$ and a 180 thermostat always. 195's are just too hot, period. they are there by the manufacturer for emissions only. I highly recommend using an occasional good injector cleaner and Gunk carbon cleaner is a must. Using a borescope i can see the shiny piston domes and the idle smooths out on start up. The serpentine belts will chirp and squeal on start up and warm up if you don't tighten the belt quite a lot. Best suv ever and i am proud to drive my 2000 every day. It is my most reliable vehicle and a lot cooler than all the other more modern suv's.
Vent the hood. The problem starts with a large engine in relation to the bay it sits in along with the unibody design which provides no gap between the body and frame. This is the root cause of the problem, air cannot escape the engine bay as readily as it is pulled in by the fan(s). If the air on the engine side of radiator cannot escape air will not flow through the radiator from outside no matter how much the fan is pulling. It's simple displacement of the air, the only way air can easily come in an enclosed area is if the air already in the enclosure has an easy way out. When I lived in the Arizona desert the trick was to space the back of the hood at the cowl up and remove the cowl/hood seal, or just cut a couple holes in the hood and put a return air furnace vent over it. My current Jeep Grand Cherokee WJ suffered the same problem, 4.7 V8 stuffed in a small hole with no easy air egress. Venting the hood reduced the under hood temp by about 30 degrees in the summer trail running with AC running and dropped the coolant temp from around 205 to around 195 which is the temp of the thermostat opening. Sitting at idle with the fan running I cannot keep my hand over the vents, there is a substantial amount of air coming out and it is HOT!
@@luisbarraza9709 find a plastic bottle, and put a small hole in the bottom of it. Fill it up with water holding your finger over the hole. Turn it upside down and let the water drain out with your finger still over the hole. Notice how slow it dribbles out. Now release your finger and watch it flow out very quickly. It is a very graphic demonstration of what I mean about air in and air out.
I believe this is the correct answer. It's no coincidence that Jeep vented the hood when they put the high output 360 in the 5.9 Grand Cherokee. This also explains why it's a known issue in the XJ and not in the YJ, TJ, and ZJ with the same engine and components.
That is exactly what I did, I cut two vent spaces out of my 2004 Grand Cherokee (with the 4.0) hood, then installed stainless steel vents with hood scoops over both sides. Never had an overheating problem again. And I did that 7 years ago.
Installed the exact same fan a week ago. Had a hard time getting the fan out as the one clip on the right side was really hard to get at. When we got it out we ended up actually braking off the clip on the old fan. Installed the new fan on easily but I actually still haven't tested it to see if it is kicking on as I was waiting to check when the temperature went up. Going to try one of your methods. Was told it was a bad electric fan from my mechanic as I was having overheating problems and the radiator I had put in from last December was still under warranty. I drive a 2000 Cherokee sport. My Dad loves the Cherokee's so much he went out and got a 2000 Cherokee limited as his main vehicle now. Thanks for the great video!
Thanks for watching! Yeah over time that metal lower clip gets rusty and can be a pain to get out, that's what happend to this Jeep on one of the previous times I removed the fan.
My 93 never over heats, the reason for the 190 degree thermostat is if run cooler would not pass smog and engine compartment was only ment for a 4 cyl engine. I also hole in cowl to let out engine bay heat...
Fan clutch...even if you think yours is good, if you are over heating replace it. My normal op temp was the half way mark...after a fan clutch its now operates at the 1/4 mark and only gets to the half mark when hot it traffic. DO IT!!!!!
Mopar offers a Middle East cooling group for the XJ. It consists of a more powerfull electric fan,and an all brass, and copper 2 core radiator. The part numbers are in the catalog.
Hey man, thanks for the video! I have two questions... 1. My 2000 jeep I bought two years ago had a coolant leak so I took it to a shop, they said it was the head gasket and a freeze plug. Coolant was still leaking, so I replaced the radiator, its hoses, the water pump, thermostat, and heater core hoses. The shop checked for cracks in the head and the block but found nothing (I doubt they checked it at all since it was warranty service and they have a history of being crooks). It's been in storage for almost a year but I don't remember seeing any leaks anywhere. Do you know where the coolant could be going? I don't smell anything in the cabin and the exhaust looks okay. 2. Do you know if the electric fan turns on with the 2000 models? I tried to wire in a direct switch to turn the fan on whenever I wanted but I heard it only turns on at high temps (~220) or when the A/C system pressure is really high as well.
To answer your first question, it's really hard to say where it would be leaking from as I am not there in person to check it out. Leaks can come from anywhere in the cooling system. On my 2001 I had it leak from a water jacket to the outside of the block and had to do a head gasket. But with yours being a 2000 model, that year the cylinder head is prone to cracking between the 3rd and 4th cylinder. I would check your oil and make sure it's not milky and sometimes if you look down the oil fill hole you might be able to see where it could have cracked. As for the electric fan, it will turn on at 218 degrees or when the AC compressor is running. If you ran a positive wire from a switch all the way up to the electric fan, it should kick on even when the vehicle is off. If it's not then it may be a bad fan like shown towards the end of this video.
You can put UV dye in the coolant and then use a black light to find leaks. If you cant find the dye with a black light then its probably either the cyl head or the heater core. Also, if you start the jeep with the oil fill cap off, you should be able to see the coolant bubbling through the crack if the head is cracked between 3rd and 4th cyl. If the head is cracked then better start searching for a TUPY casting. Although those aren't immune to the problem either. Good luck diagnosing the problem.
The 2000 did have a problem with a new head that was put on for emissions purposes. And yes some of them did crack. There was i believe a recall for it, but that was 20 years ago. The head issue was finally resolved at the factory during the model year. The fix would be to either replace with a 2001 head, or a 1999 head.
The 2003 Jeep TJ Wrangler AMC 4.0L w/o electric fans here has never overheated except when the wrong length serpentine belt, for the aftermarket Eaton M62 supercharger, slipped off at 65mph and shredded to pieces. Had to guesstimate a replacement belt size after walking several miles to the auto parts store...fun stuff.
I had a friend that bypassed his ac compressor and and swapped his trans fluid lines to the ac condenser and plugged the old holes in the radiator with brass fittings and it helped tremendously
Mine has a brand new water pump, radiator, thermostat and the fan is working but it is still overheating and getting hot in less than 10 min. The upper radiator hose gets extremely hot while the bottom radiator hose doesn’t get hot at all, what can my problem be?
How many fans do you have? My 2002 had same issue. It came with 1 fan (electric) from factory. I added a clutch fan to the electric fan and it’s at 180 always now. My neighbor has same Jeep as mine but a 2004 and hers came from factory with elector fan and clutch fan. Apparently Jeep knew it had overeat issues and fixed it in 04 by having 2 fans installed. If I take the clutch fan off mine and use just the electric fan when sitting in traffic it goes past 220. Once it boiled over. I also have a new thermostat, radiator, water pump and hoses. Ever since I added the 2nd fan (clutch fan) my overheating is gone. Ps if one hose is extremely hot and 1 isn’t hot at all that’s usually almost always a stuck thermostat. I know you said you replaced it but maybe you need a lower temperature one. If it were me… I would take the thermostat out and let it run free flow, and cool off with radiator and fan. I had a bmw that did that. A 320i. I replaced thermostat and It overheated. I took it out and it never overheated again
Should do some reading on constant tension spring clamps on cooling hoses(the clamps from the factory) they’re actually better then those aftermarket worm gear style clamps. They keep constant tension on degrading and hot/cold hoses to prevent coolant leaks in temperature changes. They’re better then those worm gear clamps that hold 1 pressure on the hose all the time. As condition of the hose changes by expanding/contracting or degrading the clamps keep constant even pressure. Just like everything else on XJ’s they used those for a reason. There are aftermarket constant tension clamps you can purchase that are easier to use like a worm gear style clamp that work well.
Great video. The cooling system is the first project i am working on. I replaced the radiator/hoses, & water pump. I have the thermostat and housing i need to replace. i got my 99 with the electric fan missing completely... so i need to get one of those too soon.
Would you happen to know where the ground wire for the cooling fan motor ends up at? My XJ is an 01' and I keep melting my connector (twice on the ground terminal so far). Now I gotta replace the connector yet again. 😖 Wondering if the ground wire ends off to an eyelet terminal that attaches to the body somewhere that may be loose or rusted.
Trying to get a 98 Cherokee classic up and running. Relay in fuse box is good. Flushed the system twice. Replaced the water pump and well as the coolant temp sensor. AC is not working as well as the electric fan. Any suggestion would be welcome.
@@jrreynolds5290 Well the fan should kick on around 220 and should be on with the AC. Do you have enough refrigerant in the ac system? It won't turn on if the pressure is too low and too high.
I finally replaced my water pump and that seemed to do most of it. The weep hole was trickling and I didn't know where it was coming from, and then one day it was literally pouring out of the large lower weep hole. Another issue I have with my AC is the compressor seems slightly difficult to turn adding a load to my belt system. Running the AC in town with stop lights and stuff make my air come out hot and sometimes overheat the engine. I haven't had overheating issues since I replaced the water pump.
My 01 has never overheated. If you have your stock shroud, the clutch works and the electric fan works it should never overheat. I can crawl all day with the AC on in the hot Kentucky summer and it doesn’t overheat. Now it did heat soak the fuel rail until I added hood spacers but now after 3/4” spacers that is fixed as well.
That is where a lot of the heat is coming from. The trans cooler lines in the radiator. The factory did use auxiliary transmission coolers on some of the XJs. Usually the UpCountry or with the factory upgraded towing package wiitch also had a thicker radiator.
Also transmission heat added to the radiator. Big tires or towing will cause the trans to not reach od tq lockup and overheat. transferring the heat to the radiator and engine.
Excelent video!! Wery well explained and resumed. I have a problem with my Cherokee that tends to overheat in hard traffic. I have found that the electric fan turns on when the motor is already averheated. I have replaced the Coolant Temperature Sensor mentioned in the video, but the problem persists. I have found there are sensors with different Temperature-Resistance performance. Could anyone tell me where I can find an online store where I can buy the right one for a 1994 Cherokee model?
Double check and make sure you don't have 2 temp sensors. One could be on the back of the head and the other by the thermostat. Some years had 2 sensors, one for the gauge and other for the fan. I would stick with factory styles of sensors and not change it up to anything aftermarket.
One major problem is that it should've been a crossflow head, and thicker deck. If you look at the radiator from the bottom, there's plenty of room for a 3-4 row radiator that goes well below the bumper valance. I might even make 2 civic radiators side by side for a chevy swap that im into.
I have 2 electric fans. I always forget, but my motor came from a 95 Tj, there are a few minor differences I run and hiccups I run into from time to time when I'm repairing and upgrading. What would be the best way to change back to a mechanical fan?
@@OutJeeping its a 2000, but it has a 95 Tj motor. The previous owner had both my xj, with a shot motor. and a tj with with a shot trans so they had some one do an engine swap. A few things in my bay are off from the OEM layout. For example I have 2 nearly identical electric fans. The fan where the mech fan would be is custom hard wired to the battery with a fuse and relay. I think I'd like to go back to mech fan.
FYI - OEM spring/constant tension clamps are the best. The key is constant tension at all temperatures(expansion/contraction). If the clamp is removed or disturbed, it is crucial that the clamp is positioned the exact orientation/location as before. In the exact indentation made on the hose by the clamp or it will leak.
I agree with that. I've had a coolant leak one time when it was -15F. But reason I don't replace them with the original clamps is due to the poor condition they are in and not always easily available to get compared to a traditional hose clamps.
Great info. I watched the first 1/2 (have to return to work) but, I'll watch the rest later. Question: Where do you drain the coolant from to flush the engine of coolant? (Have a 1991 Cherokee XJ model). I don't see an easy location that can be reached to flush it out. Thanks. Phil Jersey Shore Area
How good is aftermarket electric fans for the XJ in terms of pulling the right amount of air (CFM)? I've had a bad experience with an electric fan in the past (I don't remember the brand). It didn't fail, but was not pulling enough air to keep the system cool on my 2000 4.0L XJ in the Summer. That's why I replaced it with an OEM one, even through was very expensive.
Honestly there are so many aftermarket fans on the market, it's hard as to tell which is good and not-so-good, you mostly just have to go off of other people's reviews. I'm not sure on the correct number for CFM that's needed keep the Jeep cool. A lot of people take out the factory fan setup in Run 3 electric fans instead, which is not a bad option. But you just need to make sure to have a correct fan relay setup to have certain fans turn on at certain temperatures, and for the fans to be drawing enough air. If it were me and I was going to that setup I would compare the CFM from the new fans to the factory electric fan and try to get it close if not better.
2400 CFM in total, 3 electric fans of 800 CFM each Shroud has to be minimum just enought to support fans. If shroud is solid with only openings for fans it restricts airflow. Connect all of them running at the same time for best result in hot climates.
(Continued) If you pack too many fins into a radiator, you restrict airflow, pack too few and the air wont be turbulent enough (the more time the air can spend between the fins, the more heat can be transferred and carried out. You can thus obviously pack more fins per sq cm in a single row radiator than in a double row and so on. the moment you come to a three row or higher though, you have to start thinking about heat being trapped in the centre of the core due to air not flowing freely enough. A well designed three row will outperform a two row radiator by miles. On the aluminium side its basically the same idea with the tubes and fins, except aluminium also has round tube radiators that are used in smaller engines due to a smaller cooling capacity but a much cheaper manufacturing price tag. Everything I said above will also be moot if the system can not retain water pressure, as water boils at a higher temperature if its at a higher pressure. The moment water starts to boil, it causes steam pockets (Air lock or cavitation) to form (especially around the water pump) and that means you have no water circulation going through the engine. Point is, just adding a larger expansion bottle to your car, will already improve its cooling
I agree what you all have said. There are many ways to go about a cooling system to see what runs the most efficient. You can certainly get a 3 or 4 row to work well in these jeeps. But most people think that just buying the 3 row rad and not paying attention to how it plays, may have issues with it. The reason I say a 2 row works the best is because it has a small volume to cool off with the supplied airflow that is able to get through. And most people won't go this in depth about the thermodynamics of a cooling system like you. Now a 3 or 4 row could work good as well but it needs a higher flow of air or a good design of air louvered fins to accommodate the air flow the Jeep can provide with a stock fan setup. There are many combinations on all of these variables that could be played out. But for the simplicity of the video and for the common Joe, saying the stock setup is the simplest and efficient is the best route. It's cheap on parts, easy on the mind, and engineered from the factory to run efficiency. Don't get me wrong there's always room for improvement. With about 20 years since the last XJ built people will find flaws and better ways to go about curing this issue.
@@OutJeeping Totally agree. Few people realize how intricate a cooling system actually is. My suggestion to anyone having cooling issues is make sure they have a working thermostat, a radiator cap that keeps pressure and a larger amount of water in the system is better than less
I just replaced the radiator in my 2002 Jeep Grand Cherokee Laredo brand new $220 Canadian and its perfect and the air is ice cold and was worth going new for the price new.Great Vedeo .
Not sure if you reviewed this prior to it's release, but are you aware that you were pointing out to things out of camera angle. Though the lighting, shooting clarity and audio was spot on for a video tutorial. I personally like the closed loop that's currently on the '89 XJ I've been working on the cooling system is much easier to fill than all the various open systems I've worked on thus far. Great work thus far and I hope you are able to keep releasing as much as you can over time, thank you.
Green is what is recommended for this jeep. Other cars require different colors because of the chemical composition of what is inside to help protect the cooling system. Orange helps if protect aluminum parts a little better from corrosion.
I never had issues like not enough air flow or capacity. I have an older style with a single belt driven fan. My real issue was lag of the thermostat opening caused by the design of the thermostat housing itself and the fact it’s in front of a huge single fan. The thermostat housing would cool down so much from the air hitting it directly the thermostat would lag to open. This especially happened when I installed a lower temp 180 thermostat. How I solved it? First off if you do this, it’s at your own risk. I live in the Caribbean so no cold weather for me. This works for me and I haven’t needed to touch the coolant in over 2 years. Remove (cut off) the little piece of metal that blocks a little hole in the thermostat. This allows a little coolant to always pass by the thermostat allowing the thermostat to heat up much more quickly eliminating the lag. I honestly believe the best way is to insulate the thermostat housing but that’s something I haven’t tested.
I live in AZ and my thermostat on my TJ was stuck closed. The Jeep only survived for the previous owner on brief drives by using that one little thermostat bypass hole. Crazy that he limped it around and only drove it in the winter instead of investigating the problem. Glad he didn't crack the head in the process.
My electric fan doesn’t kick on when past 210. I’ve tested the fan and works fine. Relay works and the temp sensor has been replaced 3 times so I’m starting to think it’s a computer related problem. Any ideas on what I should do? I’m planning on getting a external auto temp switch.
![Felix "Unfair" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/Oswujxm2Ag0/mqdefault.jpg)
Austin, Bro! This is the BEST cooling system video on the net. I have been watching vehicle repair videos for years. I have to say you are great at telling the What, Why, and How. That is what people look for when watching repair videos. None of the "this thing" or "that right there". Your explanations are simple and to the point. Your repair process is methodical, step-by-step, and detailed. Showing the tab slots for the electric fan is an example. Most vids would not show it, but you know someone out there is wanting to know what you were talking about. Very well done young man, keep it up. I will be buying an XJ for a project and will follow your channel for insight and information.
Glad I could help!
2001 XJ Limited owner here. You're SPOT on with everything mentioned. Thanks for giving aid to keeping these ol' bricks rolling.
Last week it was 115 degrees here in the Phoenix valley. It was probably closer to 130-140 on the asphalt sitting in traffic. My 1999 XJ with the stock set up stayed around 210-215 while sitting in traffic. I have replaced the thermostat. E-fan and flushed the system within the last year. It all works well and the AC is always cold. If I hade the room I would have a whole field full of XJs.
I am filling my ten acres with them just got a 2 door and a pickup along with my 93, plan to get more
Tod Hollo
It’s like a game preserve for endangered machinery! God speed to you!
I'm glad I've never experience heat like that before lol. But at that point the Jeep is doing the best it can on Cooling, it probably wasn't designed to take on that kind of heat every single day. But if I lived in that environment I would have to modify the cooling system a little bit or even add hood vents to have all that hot air escape.
OutJeeping
I am conflicted about hood vents. If the engineers knew best why did it not come with vents? Having rain on the electronics seems like a bad idea. However I do see how it can help with the heat. To vent or not to vent? That is the question.
Im in Phx as well. These past two weeks I've not been driving the XJ (2000) because it runs at 210 and gets real bad heat soak when I stop at a store or something.
You can also test your electric fan by just turning on the defrost. It always runs when the defrost is engaged.
Thank you for this tip! Was wondering how to do a good test on it.
@@Bonobo277 You are welcome. It is a pretty easy way to test it without having to open the fuse box.
@DJ B It does not run 100% of the time when the AC clutch is engaged. It will be on most of the time however depending on engine temp.
That doesn't work in the 00 and 01 models. They changed it so the fan only turns on once it gets to a certain temp.
@Dean Bennett I only found out the hard way by thinking my electric fan was broken when the AC was on since I was used to it always being on in my older XJs.
I have a Jeep Wrangler 4.6 l Stroker. The extra power generates even more heat and it seems to be trapped in the engine compartment especially in traffic. I replaced the radiator with an aluminum 4 core radiator thinking doubling the number of cores would fix the problem of running about 205 degrees. It didn't, so I bought a louver attachment for the hood and cut out the areas of the hood under the 68 louvers which allow air to escape. The hardest part was the measuring and cutting holes in the hood to make it look like it came that way. It runs at 180 degrees everywhere now, as if the hood was off the Jeep leaving the engine compartment open. The matte black powder coating makes the hood attachment look pretty cool also.
I bought a 96 Cherokee new. Within a year I had gone up to the sierras to explore some fire roads. It was about 85 up there. As I was climbing a long upwards grade road that I would rate mild for a jeep, I noticed the temp climbing towards overheating. Was a bit surprised by that so I turned the ac off and turned the heater on and that cooled it down enough. Got to our destination,and let it idle for a bit then shut it off and opened the hood. After that on our way back all was well. But i just never got back to figuring why it got so hot since i didnt think it was working that hard. Anyways, when i went offroad i just turned the ac off. Unfortunately i got into an accident caused by the other driver that caused me to become a paraplegic. Sold the jeep to my bill. Loved that jeep and it was always offroad on the weekends. Anyway, now i have an idea what to do the next time !
Not so fun fact, the reason the XJ runs so hot is due to the 4.0 wasn't intended to be an option for the XJ. The cooling system was designed for the 2.5.
You are correct!
I totally agree with you. I took out my stock radiator and fan clutch and I realized that, with minimal trimming with grinder and dremel - one can fit a 18" x 18" x 3" all aluminum radiator with a 16" fan and still retain the ac condenser- which i fitted 2 smaller fans i front of the ac condenser (come on when the ac is turned on) for even more air flow. With this setup I got 170 water temp under 90 degrees. Above that it went to max of 215 in 110 degree weather. So, i cut into the hood with the large hyline vents so can't wait till next year to see if it lowers the 215 in 110 weather. I live in mostly dry desert. Prob wouldn't cut the vents in Louisiana but the vents don't really make it wetter then before. At 70 mph rain would cover the entire engine from the holes in the grille.
What parts of the cooling system are inadequate?
@@gregwendt7172stock there is no inadequacy but it is marginal. The clutch on the mechanical fan loses its ability to transfer power, the radiator starts to clog, the coolant gets old. It is also possible to have a fault such as a weakened pressure cap or leaking core plugs etc.
I run all day in 40 degrees celcius and it can run fine when maintained but worn fan clutches etc can creep up on you.
@@julianlord2697 Thanks for replying. I've tested everything (fan clutch.etc.). The coolant is new and there is no leking from the block, etc. The radiator is clean and it's an aftermarket 3-row aluminum welded performance unit. The heater core was plugged but was backflushed until clean. I replaced the heater hoses and ran them away from the engine and around the fender wells. They are longer this way and allow for a slight increase in total coolant capacity. I was a mechanic for quite a few years and solved many overheating problems but nothing has worked, so far, on this jeep. the clutch fan and the electric fan work according to specs. I replaced the cap and it has the appropriate spring pressure. I'm currently shopping for a new radiator and it will be a higher capacity 4-row type. This way, I'll be able to choose the fin spacing and tube size for the best cooling. It doesn't overheat often but I want it even better.
Great video! The engineers did know what they were doing, but remember this engine bay was designed for the smaller 2.5 L and 2.8 L engines. The 4.0 L sits too high and crowds the engine bay. I have a very built-out XJ and I tow an off-road trailer. Stock cooling just doesn't cut the cake at all for me. The best improvement I made was going to a Novak single core radiator with 1.5" tubing inside, combined with 3 electric fans. I relocated the transmission cooler (away from the radiator) and added an engine cooler (also away from the radiator) and my problems are 100% solved. Even taking grades with the AC running! Thanks again for the very detailed video!
The more videos you post, the more I realize is wrong with my XJ! Really appreciate the good info.
Great video. Can’t thank you enough. I found my electrical connection from fan to harness causing the fan not to come on. One of the male ends was not inserted properly into the female end, causing and improper connection. You saved me the cost of the fan and labor. Thanks buddy. Keep up the good work.
You actually want spring style clamps on radiator hoses. Because of thermal dynamics the rubber hoses and plastic radiator necks can shrink and expand depending on ambient tempatures. Spring clamp allows it to maintain the same clamping pressure as it shrinks or expands and not cause leaks.
Yes, I caught that too. The old urban myth about factory spring clamps being bad ! . .. . The other advantage of the spring clamps is that there is fully circumferential clamping.
Right! Screw-type clamps don't tighten themselves. Just as the video author says several times, the engineers knew what they were doing. The only caveat being the clamp may get tired. A tired clamp does not mean you replace it with an inferior clamp. Stick with the factory style clamps, and healthy hoses that are not all compressed where the clamps go. Hoses and clamps are inexpensive preventative maintenance.
@@99jeepxjguy97 spring clamps are the best..... project farm did a test on all automotive clamps and those were the best.
@@MiguelGarcia-vj7oo Yes, I agree that spring clamps are the best.. I have known this for years. I did not know project farm had done a test, however.
Make sure all hoses, radiator, shroud, thermostat, radiator cap, water pump, fan clutch, and electric fan are functional and in good shape. Make sure your fluid is good, bled properly, and at the correct level. If you do all this and the engine isn't broken, you will not have cooling issues.
I live in Tucson, AZ and it gets extremely hot. I drive a '92 Comanche as a daily driver and company vehicle for my business. I never have any issues cooling, even with the A/C on Max, in traffic, in the summer when it's 115° outside.
I have a '96 High Output 4.0 and solved my overheating problem with a high-performance thermostat. I also used an air grinder to grind out the interior of the water thermostat housing. That removed any sharp angles and enlarged the interior of the housing to make it smooth out the flow of coolant. My coolant temps dropped considerably...
Hmm . . . Interesting. I hadn't considered the deburring of the housing.
11:48 Interesting, the water pumps for my 93 XJ 4.0 and 2004 WJ say reverse rotation on the Napa parts site.
Depends on year of vehicle due to belt routing.
My 1997 XJ stays around the 190-205 degree temperature, all I did was install a new radiator, new fan clutch and new thermostat with a 1/8’ hole drilled on top. Zero overheating issues even in traffic and I live in Tucson and summer temps are around 108’ and also while on the trail.
Just a note from a retired mech. When checking things as a fan as you did, it's best to check the whole system, starting at the sensor and the fuse. This way you dont get other surprises.
Very good series of videos, thanks for sharing your time on it. One small correction on the older 4.0s is from 87-88 there is a temp sender for the idiot light or gauge, depending on cluster. That grounds on the head where it’s mounted at the rear corner, driver’s side, and a single post out to the gauge/ light. There also is the temp sender, 2 wire in the block below the intake near the knock sensor that goes to the ECM. One wire is ECM sensor ground and the other is signal to ECM. In 89 they moved the ECM sender to the t-stat housing and kept the gauge/ light sender on the back of the head. These engines through 89-90 had a thermal switch in the radiator to close the electric fan circuit’s relay. With the HO from 91-95 that switch was no longer needed, as the sender in the t-stat housing allowed the ECM to calculate fueling and electric fan control with the value from a single input, whereas before the electric fan wasn’t controlled by the ECM, just a simple thermal switch. And of course 91 was the start of the open cooling system so the radiator changed to add a cap and over flow line and omitted the fan control switch. 96-01 saw changes to the ECM and possibly a couple changes to wiring but the gauge/ light sender remained in the back of the head and the ECM temp input in the t-stat housing
Most vehicles today have only a 2 row radiator core. I have had vehicles that I upgraded to a 3 or 4 row radiator core. That gave excellent results for towing and offroad.
Another trick is ceramic thermal barrier coatings on the exhaust manifold or headers. My '03 Ford Explorer 4wd has ceramic coated JBA shorty headers. When I take it in for a California smog inspection. They lift the hood, and think the engine is cold. They hook up to the OBD2 port. And find the engine is warm. I plan on buying the ceramic coated headers for my '96 Jeep ZJ.
Very well explained !! I have watched some of your past videos and i like them . Just subscribed to your channel . Keep up the great work .
Very good work sir. I would recommend Hi-tac for gaskets. It makes installation very easy and unlike RTV it can be cleaned with solvents. Especially if you have an irregular mating surface. Plus squeeze out doesn't contaminate the system.
Great video!! Extremely informative. My 99’ Jeep runs super hot in this 90 degree weather.
Did clean the inside of the cooling system on my Jeep Wrangler 4.0 with evaporust. I had a light rust problem that showed up after a flush. Cools it like an iceberg since it did it.
@ hua Thai - I never thought of this. How long did you allow the evaporust to sit in there before you flushed it? Can anyone think of a reason this wouldn’t be a good idea?
@@scottbollinger3999Empty the system out, put it in, fill it up with just regular tap water. Put the cap on the radiator and did a 200 miles road trip. It works best when hot. Flush it out immediately afterwards. Re did the flush with distilled water and anti freeze and done. Did it 3 years ago and still no problem so far. When you flush it out the water is dirty black.
@@huathai8204 it’s an iron block so that makes perfect sense. I’ve used evaporust on other things and never thought of this. I guess I’d just be afraid of it dislodging flakes or whatever and blocking passages but I guess that could happen at anytime
Wow! Did you say that red XJ had 300,000 miles? Looks very well maintained for those miles. But I suppose that is why it has 300,000 on it. Just wanted to back up ToneDeaf on the spring clamps being a better system than the worm gear ones. Great video. Well put together. Thank you!
I recently picked up a 97 Wrangler TJ. It was purchased by a friend of mine from his deceased friend to help the wife pay bills. Long story short it sat in his backyard for several years and it didn't have coolant in it just water. The clutch on the fan was working okay. When I got it it, was full of rust, full of crud. I had to flush the heater core. I ended up replacing the radiator, the water pump and I went to 160° thermostat. Now it actually will maintain temperature without overheating. But what a pain in the butt when people don't use antifreeze.
IIRC, the fan kicks on at 195.
It'll also kick on if the front temp sensor is disconnected.
You can also get rid of the diaper under the engine, which is probably a oil-soaked fire hazard by now.
My Jeep kept sitting at 200° and then I realized it didn’t have a fan shroud. Threw one on and it dropped my temps from 200 down to 185-190
It's supposed to run at 190-220°f
Graham Burgdorf exactly right. Factory thermostat =195.
Agree with everything you said. Tried the CSF 3 row and it didn't cool any better. Sprung a leak after 2 or 3 years and I replaced it with stock style. ZJ fan clutch was the best upgrade I've done to keep it cool. I used a flowkooler water pump and had no problems for 10 years or so. Parts store pumps just didn't hold up.
I find having the auxiliary fan on a manual switch and a little lower temp thermostat for the summer works well. Still stays about 195 with the ac on in a 100 degree day. I just switch back to a higher thermostat in the winter. I do have a little more capacity in my radiator than stock. Heat wrapping the headers down to the y pipe is also a good modification. Helps limit heat soak and keeps the trans and transfercase a bit cooler. Later 4.0's had a heat shield under the fuel rail which you can use in any older 4.0. Just be careful not to let it run too cool though.
manual elec fan switch, 180 therm and took off heat shield junk for better airflow around manifold side......let fan run minute or two b4 /after running on hot days or sitting in traffic or drive thru works great
I have a 98 XJ with, as of today, 307,002 miles on it and I have had it as my daily driver for over 3 yrs and it hasn't over heated once. And it's sad to say that I have never changed or flushed out the coolant system nor have I added any anti-freeze I also would not be surprised to find out that it's probably the original transmission fluid 4.0 straight-6 rules! JS LOL
Super informative video. I'm redoing the entire cooling system on my 97 xj. The guy before me used some of the worst aftermarket parts I've ever seen. This was a great run through. Thanks brother
I installed a 36amp fan in my jeep 4.0 and it stays nice and cool.
The stock one that I took out with a 9 amp huge difference☺
Any mods required? Mind sharing a link?
@@luisbarraza9709 I went to O'Reilly's and bought 36amp cooling fan it wasn't specifically for a Jeep I just wanted something with some power and I just hardwired it directly in fortunately for me there was already a 40 amp fuse under the hood in the fuse box so it worked out pretty good.
I live in Texas ,auto transmission sucks and heats up rad temps so I slapped a bnm with temp sensor transmission stays under 200° out of the torque converter , but in cold temps cardboard on the grill is my fix lol
The spring hose clamps are designed to expand and contract with the different
Temperatures of the engine coolant.
Another Awesome very helpful, and informative video Thanks Again
I have 2 cherokee sports with 4.0 and a 318 gr cherokee limited. I flush the engines as the cast iron blocks rust a lot inside. on the 2001 i used 911 rust dissolver in the motor. It mixes with water and i let it sit for weeks starting occasionally. It removes most of the rust. New 3 core aluminum racing radiators for about 110$ New aftermarket water pumps, 50$ and a 180 thermostat always. 195's are just too hot, period. they are there by the manufacturer for emissions only. I highly recommend using an occasional good injector cleaner and Gunk carbon cleaner is a must. Using a borescope i can see the shiny piston domes and the idle smooths out on start up. The serpentine belts will chirp and squeal on start up and warm up if you don't tighten the belt quite a lot. Best suv ever and i am proud to drive my 2000 every day. It is my most reliable vehicle and a lot cooler than all the other more modern suv's.
fan shroud and clean cooling system.......no problems, in the trails or traffic
Very well explained , good information to know .
Vent the hood. The problem starts with a large engine in relation to the bay it sits in along with the unibody design which provides no gap between the body and frame. This is the root cause of the problem, air cannot escape the engine bay as readily as it is pulled in by the fan(s). If the air on the engine side of radiator cannot escape air will not flow through the radiator from outside no matter how much the fan is pulling. It's simple displacement of the air, the only way air can easily come in an enclosed area is if the air already in the enclosure has an easy way out. When I lived in the Arizona desert the trick was to space the back of the hood at the cowl up and remove the cowl/hood seal, or just cut a couple holes in the hood and put a return air furnace vent over it. My current Jeep Grand Cherokee WJ suffered the same problem, 4.7 V8 stuffed in a small hole with no easy air egress. Venting the hood reduced the under hood temp by about 30 degrees in the summer trail running with AC running and dropped the coolant temp from around 205 to around 195 which is the temp of the thermostat opening. Sitting at idle with the fan running I cannot keep my hand over the vents, there is a substantial amount of air coming out and it is HOT!
Fingers crossed this works, I just ordered some hood blocks to vent the hood.
@@luisbarraza9709 find a plastic bottle, and put a small hole in the bottom of it. Fill it up with water holding your finger over the hole. Turn it upside down and let the water drain out with your finger still over the hole. Notice how slow it dribbles out. Now release your finger and watch it flow out very quickly. It is a very graphic demonstration of what I mean about air in and air out.
I believe this is the correct answer. It's no coincidence that Jeep vented the hood when they put the high output 360 in the 5.9 Grand Cherokee. This also explains why it's a known issue in the XJ and not in the YJ, TJ, and ZJ with the same engine and components.
If you watch Matt's Recovery Towing videos, he did this to the "Banana" XJ.
He has a video explaining how he fixed the overheating issues.
That is exactly what I did, I cut two vent spaces out of my 2004 Grand Cherokee (with the 4.0) hood, then installed stainless steel vents with hood scoops over both sides. Never had an overheating problem again. And I did that 7 years ago.
Installed the exact same fan a week ago. Had a hard time getting the fan out as the one clip on the right side was really hard to get at. When we got it out we ended up actually braking off the clip on the old fan. Installed the new fan on easily but I actually still haven't tested it to see if it is kicking on as I was waiting to check when the temperature went up. Going to try one of your methods. Was told it was a bad electric fan from my mechanic as I was having overheating problems and the radiator I had put in from last December was still under warranty. I drive a 2000 Cherokee sport. My Dad loves the Cherokee's so much he went out and got a 2000 Cherokee limited as his main vehicle now. Thanks for the great video!
Thanks for watching! Yeah over time that metal lower clip gets rusty and can be a pain to get out, that's what happend to this Jeep on one of the previous times I removed the fan.
My 93 never over heats, the reason for the 190 degree thermostat is if run cooler would not pass smog and engine compartment was only ment for a 4 cyl engine. I also hole in cowl to let out engine bay heat...
Great video very good explanation of the entire heating cooling system including how to test. Thanks for all the info.
U did a good job on this video. Very detailed explanation
Fan clutch...even if you think yours is good, if you are over heating replace it. My normal op temp was the half way mark...after a fan clutch its now operates at the 1/4 mark and only gets to the half mark when hot it traffic. DO IT!!!!!
Should the mechanical fan be kinda stiff to turn by hand?
Mopar offers a Middle East cooling group for the XJ. It consists of a more powerfull electric fan,and an all brass, and copper 2 core radiator. The part numbers
are in the catalog.
Hey man, thanks for the video! I have two questions...
1. My 2000 jeep I bought two years ago had a coolant leak so I took it to a shop, they said it was the head gasket and a freeze plug. Coolant was still leaking, so I replaced the radiator, its hoses, the water pump, thermostat, and heater core hoses. The shop checked for cracks in the head and the block but found nothing (I doubt they checked it at all since it was warranty service and they have a history of being crooks). It's been in storage for almost a year but I don't remember seeing any leaks anywhere. Do you know where the coolant could be going? I don't smell anything in the cabin and the exhaust looks okay.
2. Do you know if the electric fan turns on with the 2000 models? I tried to wire in a direct switch to turn the fan on whenever I wanted but I heard it only turns on at high temps (~220) or when the A/C system pressure is really high as well.
To answer your first question, it's really hard to say where it would be leaking from as I am not there in person to check it out. Leaks can come from anywhere in the cooling system. On my 2001 I had it leak from a water jacket to the outside of the block and had to do a head gasket. But with yours being a 2000 model, that year the cylinder head is prone to cracking between the 3rd and 4th cylinder. I would check your oil and make sure it's not milky and sometimes if you look down the oil fill hole you might be able to see where it could have cracked.
As for the electric fan, it will turn on at 218 degrees or when the AC compressor is running. If you ran a positive wire from a switch all the way up to the electric fan, it should kick on even when the vehicle is off. If it's not then it may be a bad fan like shown towards the end of this video.
You can put UV dye in the coolant and then use a black light to find leaks. If you cant find the dye with a black light then its probably either the cyl head or the heater core. Also, if you start the jeep with the oil fill cap off, you should be able to see the coolant bubbling through the crack if the head is cracked between 3rd and 4th cyl. If the head is cracked then better start searching for a TUPY casting. Although those aren't immune to the problem either. Good luck diagnosing the problem.
The 2000 did have a problem with a new head that was put on for emissions purposes. And yes some of them did crack. There was i believe a recall for it, but that was 20 years ago. The head issue was finally resolved at the factory during the model year. The fix would be to either replace with a 2001 head, or a 1999 head.
The 2003 Jeep TJ Wrangler AMC 4.0L w/o electric fans here has never overheated except when the wrong length serpentine belt, for the aftermarket Eaton M62 supercharger, slipped off at 65mph and shredded to pieces. Had to guesstimate a replacement belt size after walking several miles to the auto parts store...fun stuff.
I had a friend that bypassed his ac compressor and and swapped his trans fluid lines to the ac condenser and plugged the old holes in the radiator with brass fittings and it helped tremendously
Best detailed video everytime!
I learned a lot !
I always wondered why my passenger floor was wet 🤣
Mine has a brand new water pump, radiator, thermostat and the fan is working but it is still overheating and getting hot in less than 10 min. The upper radiator hose gets extremely hot while the bottom radiator hose doesn’t get hot at all, what can my problem be?
How many fans do you have? My 2002 had same issue. It came with 1 fan (electric) from factory. I added a clutch fan to the electric fan and it’s at 180 always now. My neighbor has same Jeep as mine but a 2004 and hers came from factory with elector fan and clutch fan. Apparently Jeep knew it had overeat issues and fixed it in 04 by having 2 fans installed. If I take the clutch fan off mine and use just the electric fan when sitting in traffic it goes past 220. Once it boiled over. I also have a new thermostat, radiator, water pump and hoses. Ever since I added the 2nd fan (clutch fan) my overheating is gone. Ps if one hose is extremely hot and 1 isn’t hot at all that’s usually almost always a stuck thermostat. I know you said you replaced it but maybe you need a lower temperature one. If it were me… I would take the thermostat out and let it run free flow, and cool off with radiator and fan. I had a bmw that did that. A 320i. I replaced thermostat and It overheated. I took it out and it never overheated again
I put a mechanical fan in with the electric fan and it's now sitting around 190 in mine. I also installed a trans cooler.
Thanks for the video. I'm about to start this in the next 10 minutes.
Great vid as always 💪
I run 180 in my xj. And it did help it run a little cooler!
Should do some reading on constant tension spring clamps on cooling hoses(the clamps from the factory) they’re actually better then those aftermarket worm gear style clamps. They keep constant tension on degrading and hot/cold hoses to prevent coolant leaks in temperature changes. They’re better then those worm gear clamps that hold 1 pressure on the hose all the time. As condition of the hose changes by expanding/contracting or degrading the clamps keep constant even pressure. Just like everything else on XJ’s they used those for a reason. There are aftermarket constant tension clamps you can purchase that are easier to use like a worm gear style clamp that work well.
Agreed. The old urban myth about the spring clamps just won't die!
Great video. The cooling system is the first project i am working on. I replaced the radiator/hoses, & water pump. I have the thermostat and housing i need to replace. i got my 99 with the electric fan missing completely... so i need to get one of those too soon.
Would you happen to know where the ground wire for the cooling fan motor ends up at? My XJ is an 01' and I keep melting my connector (twice on the ground terminal so far). Now I gotta replace the connector yet again. 😖 Wondering if the ground wire ends off to an eyelet terminal that attaches to the body somewhere that may be loose or rusted.
Could be, check behind the airbox by the wire harness, there is a couple ground screws there. You could also create a new ground for the fan as well.
@@OutJeeping Cool thanks man! Great idea, I'll probably just ground the fan to a nearby body chassis point.
Really thorough and to the point. A great video!
Trying to get a 98 Cherokee classic up and running. Relay in fuse box is good. Flushed the system twice. Replaced the water pump and well as the coolant temp sensor. AC is not working as well as the electric fan. Any suggestion would be welcome.
Have you tested the fan by hot wiring it?
Yes the e fan as well ac work with power from a test light. Relays in box are good. Have moved them around to test.
@@jrreynolds5290 Well the fan should kick on around 220 and should be on with the AC. Do you have enough refrigerant in the ac system? It won't turn on if the pressure is too low and too high.
I finally replaced my water pump and that seemed to do most of it. The weep hole was trickling and I didn't know where it was coming from, and then one day it was literally pouring out of the large lower weep hole.
Another issue I have with my AC is the compressor seems slightly difficult to turn adding a load to my belt system. Running the AC in town with stop lights and stuff make my air come out hot and sometimes overheat the engine. I haven't had overheating issues since I replaced the water pump.
if you are using a molded lower radiator hose it must have spring inside the hose . or use universal hose that the spring is molded into the hose.
Nice video as always - still waiting for a heater core replacement video😂
I second the heater core video. On my to-do list this fall.
V good video! My understanding of my car has def improved😂
Great video lots of fun to watch...
My 01 has never overheated.
If you have your stock shroud, the clutch works and the electric fan works it should never overheat. I can crawl all day with the AC on in the hot Kentucky summer and it doesn’t overheat. Now it did heat soak the fuel rail until I added hood spacers but now after 3/4” spacers that is fixed as well.
What about the transmission? What do you recommend for a trans cooler?
I have a video covering the transmission cooler install. I went with a Hayden aftermarket cooler. ruclips.net/video/5jsABbt6e9Q/видео.html
That is where a lot of the heat is coming from. The trans cooler lines in the radiator. The factory did use auxiliary transmission coolers on some of the XJs. Usually the UpCountry or with the factory upgraded towing package wiitch also had a thicker radiator.
I would recommend using the spring in that lower hose. Even the new ones can get hot and collapse.
Also transmission heat added to the radiator. Big tires or towing will cause the trans to not reach od tq lockup and overheat. transferring the heat to the radiator and engine.
Excelent video!! Wery well explained and resumed. I have a problem with my Cherokee that tends to overheat in hard traffic. I have found that the electric fan turns on when the motor is already averheated. I have replaced the Coolant Temperature Sensor mentioned in the video, but the problem persists. I have found there are sensors with different Temperature-Resistance performance. Could anyone tell me where I can find an online store where I can buy the right one for a 1994 Cherokee model?
Double check and make sure you don't have 2 temp sensors. One could be on the back of the head and the other by the thermostat. Some years had 2 sensors, one for the gauge and other for the fan. I would stick with factory styles of sensors and not change it up to anything aftermarket.
One major problem is that it should've been a crossflow head, and thicker deck. If you look at the radiator from the bottom, there's plenty of room for a 3-4 row radiator that goes well below the bumper valance.
I might even make 2 civic radiators side by side for a chevy swap that im into.
I have 2 electric fans. I always forget, but my motor came from a 95 Tj, there are a few minor differences I run and hiccups I run into from time to time when I'm repairing and upgrading. What would be the best way to change back to a mechanical fan?
What year is your XJ? I believe the XJ fan and belt routing changed from 95 to 96.
@@OutJeeping its a 2000, but it has a 95 Tj motor. The previous owner had both my xj, with a shot motor. and a tj with with a shot trans so they had some one do an engine swap. A few things in my bay are off from the OEM layout. For example I have 2 nearly identical electric fans. The fan where the mech fan would be is custom hard wired to the battery with a fuse and relay. I think I'd like to go back to mech fan.
What's the electric fan part number and will it work on a 1996 RHD Cherokee Sport?
I love your channel! So helpful.
Why don't I find a tensioner or idler for the serpentine?? Nada??
What year is your Jeep?
@@OutJeeping 87 Comanche Pioneer Metric ton 4.0 L 6 long bed and Dana 44 tracklok etc
Thanks from Ensenada México 👍🏾👍🏾
thank you and HAVE A GREAT DAY!
FYI - OEM spring/constant tension clamps are the best. The key is constant tension at all temperatures(expansion/contraction). If the clamp is removed or disturbed, it is crucial that the clamp is positioned the exact orientation/location as before. In the exact indentation made on the hose by the clamp or it will leak.
I agree with that. I've had a coolant leak one time when it was -15F. But reason I don't replace them with the original clamps is due to the poor condition they are in and not always easily available to get compared to a traditional hose clamps.
Cool tip, pun intended, about disconnecting the coolant sensor. I just turn A/C on and efan comes on, if it doesn't it's bad, or not getting power.
Nicely done Austin....
Great info. I watched the first 1/2 (have to return to work) but, I'll watch the rest later.
Question: Where do you drain the coolant from to flush the engine of coolant? (Have a 1991 Cherokee XJ model). I don't see an easy location that can be reached to flush it out. Thanks.
Phil
Jersey Shore Area
There is a radiator petcock on the passenger side but its not an easy location. Otherwise pulling the lower radiator hose would be the easiest.
@@OutJeeping Thanks for the info. Appreciated.
Phil
Jersey Shore area
How do ya remove the fan schroud?
Remove bolts and fish out through the top.
How good is aftermarket electric fans for the XJ in terms of pulling the right amount of air (CFM)? I've had a bad experience with an electric fan in the past (I don't remember the brand). It didn't fail, but was not pulling enough air to keep the system cool on my 2000 4.0L XJ in the Summer. That's why I replaced it with an OEM one, even through was very expensive.
Honestly there are so many aftermarket fans on the market, it's hard as to tell which is good and not-so-good, you mostly just have to go off of other people's reviews. I'm not sure on the correct number for CFM that's needed keep the Jeep cool. A lot of people take out the factory fan setup in Run 3 electric fans instead, which is not a bad option. But you just need to make sure to have a correct fan relay setup to have certain fans turn on at certain temperatures, and for the fans to be drawing enough air. If it were me and I was going to that setup I would compare the CFM from the new fans to the factory electric fan and try to get it close if not better.
2400 CFM in total, 3 electric fans of 800 CFM each Shroud has to be minimum just enought to support fans. If shroud is solid with only openings for fans it restricts airflow. Connect all of them running at the same time for best result in hot climates.
(Continued) If you pack too many fins into a radiator, you restrict airflow, pack too few and the air wont be turbulent enough (the more time the air can spend between the fins, the more heat can be transferred and carried out. You can thus obviously pack more fins per sq cm in a single row radiator than in a double row and so on. the moment you come to a three row or higher though, you have to start thinking about heat being trapped in the centre of the core due to air not flowing freely enough.
A well designed three row will outperform a two row radiator by miles.
On the aluminium side its basically the same idea with the tubes and fins, except aluminium also has round tube radiators that are used in smaller engines due to a smaller cooling capacity but a much cheaper manufacturing price tag.
Everything I said above will also be moot if the system can not retain water pressure, as water boils at a higher temperature if its at a higher pressure.
The moment water starts to boil, it causes steam pockets (Air lock or cavitation) to form (especially around the water pump) and that means you have no water circulation going through the engine.
Point is, just adding a larger expansion bottle to your car, will already improve its cooling
I agree what you all have said. There are many ways to go about a cooling system to see what runs the most efficient. You can certainly get a 3 or 4 row to work well in these jeeps. But most people think that just buying the 3 row rad and not paying attention to how it plays, may have issues with it. The reason I say a 2 row works the best is because it has a small volume to cool off with the supplied airflow that is able to get through. And most people won't go this in depth about the thermodynamics of a cooling system like you. Now a 3 or 4 row could work good as well but it needs a higher flow of air or a good design of air louvered fins to accommodate the air flow the Jeep can provide with a stock fan setup. There are many combinations on all of these variables that could be played out. But for the simplicity of the video and for the common Joe, saying the stock setup is the simplest and efficient is the best route. It's cheap on parts, easy on the mind, and engineered from the factory to run efficiency. Don't get me wrong there's always room for improvement. With about 20 years since the last XJ built people will find flaws and better ways to go about curing this issue.
@@OutJeeping Totally agree. Few people realize how intricate a cooling system actually is.
My suggestion to anyone having cooling issues is make sure they have a working thermostat, a radiator cap that keeps pressure and a larger amount of water in the system is better than less
I just replaced the radiator in my 2002 Jeep Grand Cherokee Laredo brand new $220 Canadian and its perfect and the air is ice cold and was worth going new for the price new.Great Vedeo .
My temperature gauge seems to be running in the 200 to 210 range. So you're saying that is ok? Seemed kind of hot to me.
does the ingnition have to be on to test the fan ?
If you jump it to the battery no
the efanon my 98 turns on at 223 and turns off at 215, is that normal?
It should be around 220 +-5 degrees.
yeah my 98 turns on at 223 and off at 217 i confirmed with scan tool
I ordered a different one that was more expensive, how did this one hold up?
Not sure if you reviewed this prior to it's release, but are you aware that you were pointing out to things out of camera angle. Though the lighting, shooting clarity and audio was spot on for a video tutorial. I personally like the closed loop that's currently on the '89 XJ I've been working on the cooling system is much easier to fill than all the various open systems I've worked on thus far. Great work thus far and I hope you are able to keep releasing as much as you can over time, thank you.
I put a mechanical fan from an older jeep. Just make sure you have the old style water pump with the threaded shaft.
Great video, question about coolant: is it orange better than green one?
Green is what is recommended for this jeep. Other cars require different colors because of the chemical composition of what is inside to help protect the cooling system. Orange helps if protect aluminum parts a little better from corrosion.
Stock radiator had 2 rows?
I never had issues like not enough air flow or capacity. I have an older style with a single belt driven fan. My real issue was lag of the thermostat opening caused by the design of the thermostat housing itself and the fact it’s in front of a huge single fan. The thermostat housing would cool down so much from the air hitting it directly the thermostat would lag to open. This especially happened when I installed a lower temp 180 thermostat.
How I solved it? First off if you do this, it’s at your own risk. I live in the Caribbean so no cold weather for me. This works for me and I haven’t needed to touch the coolant in over 2 years. Remove (cut off) the little piece of metal that blocks a little hole in the thermostat. This allows a little coolant to always pass by the thermostat allowing the thermostat to heat up much more quickly eliminating the lag.
I honestly believe the best way is to insulate the thermostat housing but that’s something I haven’t tested.
Or drill a tiny hole in the tstat
I live in AZ and my thermostat on my TJ was stuck closed. The Jeep only survived for the previous owner on brief drives by using that one little thermostat bypass hole. Crazy that he limped it around and only drove it in the winter instead of investigating the problem. Glad he didn't crack the head in the process.
How would you check the relay to make sure that wasn't the issue?
You can swap relays with others in the box, if it starts working again then you would know that the relay is bad.
This guy is a great instructor. Subscribe!!
NP you answered my question. Good instructions! Thx
My electric fan doesn’t kick on when past 210. I’ve tested the fan and works fine. Relay works and the temp sensor has been replaced 3 times so I’m starting to think it’s a computer related problem. Any ideas on what I should do? I’m planning on getting a external auto temp switch.
It should kick on around 220 if everything is working properly.
Standard pumps are for gm v belt engines. Basically 86 and older jeeps.
Reverse is for serpentine.
At what temperature should the e fan kick in 99 jeep xj?
Around 215-220ish
Thank you 👍🏼