@@commanderdan2319 no, I don't get it, it got pretty hot a few times, maybe the metal heated and melded a bit, or the older oil started thickening enough it cant get through. I'll find out when I do an oil change soon
Me and my gf's dad both rebuilt our jeep motors a half year apart and they're both leaking out the rear main seals now. Its comforting knowing many others share this problem.
I have a 2000 XJ, 275000+ miles. Just replaced the cylinder head gasket, other gaskets and head bolts. Yeah it's loud. It's getting 16mpg/city before the gasket changes. Great video!!
Thank you! After getting a second opinion from a mechanic, I've learned my valve cover gasket (a few hundred) and not my head gasket needs replacement (5k per now previous mechanic, grrr). Your video gave me some other insights I didn't have but need to have. I love my 94 Cherokee Sport 2 door 4 liter and have been driving it for 25 years and plan on continuing. Was here to learn and I did! Much obliged.
I have a 2004 Jeep Grand Cherokee 4.0 liter.. I am the original owner with over 201k miles it and no blow up thank God😄YES you have to maintain them as in any other vehicle and for those driving off road even MORE SO., I don't take my Jeep off road. I just changed out original thermostat and water pump this past Thursday due to water pump gasket. Over all I think the 4.0 is one of the easiest engines on can work on, Love ❤️ it...
Great video brother. I have had a few 4.0 and argue with the world that the 4.0 has no problems. I agree most are easy fixes as long as the exhaust bolts don’t snap. I also had a head crack too but easy to work on motor and plenty of parts.
I'm sitting on a XJ, ZJ and a WJ. All 3 get driven on a regular bases except for the zj that stays in the garage when the snow flies Only problem I have so far is the engine noise. It goes away in the zj after it warms up. Makes noise in the wj after it warms up and never goes away in the xj. Great motors been a fan since I got the xj and been adding ever since.
I bought my new 1998 Grand Cherokee (4.0L) brand new. Still own and drive it. Never experienced any of these problems except a tiny leak in the rear main seal. It doesn't leak enough to worry about. The engine oil level never changes. I never had to add any oil between oil changes. As for noise. the 4.0 is a very quiet engine. It runs very smoothly. You should hear the noises in my 2016 4 Runner! It's been making very loud tapping noise since new. Toyota says it's normal. I sure hope this thing is as reliable as my Jeep. I used to have a 2010 Tacoma. It was full of problems. The engine sounded like an old diesel, at idle with AC turned on. Again. Toyota said it was normal. Manual transmission and the clutch was a disaster (grinding shifts). Throw out bearings had to be replaced 3 times within 60k miles I'd owned it. Sold that piece of sh*t. FYI: I did nothing but oil changes and routine maintenance with my Jeep in the 23 years I've owned it! I did use it for 4 wheeling in Arizona mountains quite a bit and towed a 2 ton travel trailer a lot with it.
Yup got all these noises both from engine and transmission. It been bothering me for a while. But I do like that sound of clanking that sound like a diesel. I will keep it that way. Adds character
A couple things I’ve taken away from my 4 years into 4.0s As long as there well lubricated and have some sort of heat absorption they’ll do just fine my 4.0 has a little tick but it’s not a bad tick same with my AW4 as long as it isn’t over heating and as long as it has some sort of fluid in it you’ll be just fine
I bought a Jeep Grand Cherokee Laredo for$650.00. it was in sad 😢 shape. It had 240,000 miles on it. My mechanic said it looked like it had never had a tune up. The coil packs were misfiring. I had a crankshaft sensor replaced, both oxygen sensors, some sort of cooling sensors, the thermostat,gas cap, and fuel filter. The old filter weighed a couple pounds compared to the new one which weighed a few ounces. The odd thing is that I can't tell the difference in performance from when I first bought it and after all the repairs. It clatters like the devil when I get on the throttle. It doesn't use any oil. I use royal purple oil and 93 octane gas. I get about 17 mpg. I 💕 love it.
Don't forget the notorious head crack on the bunch that were machined bad at the plant-hot temps and not keeping up with the cooling system-there you have it-cylinder wall crack resulting in the famous mysterious case of the lowering coolant level.-Whys it down???
I got a exhaust manifold with the flex pipes and still cracked right at the collector! Haha going to weld it back up today and do solid motor mounts hopefully that works!
Ronnie, good video. Any mechanism has some weaknesses. The 4.0L has fairly minor ones, with well-known fixes. About the longevity of the 4.0L, they are an inline engine. That means the 4.0L has 7 main bearings, while a V8 only has 5 main bearings. This makes the bottom end tougher than V engines. And if the bottom end doesn't blow up, most people will fix the rest. I have even considered making a front-end bracket for the CPS and put a magnet in the harmonic balancer. That would make them run cooler and be easier to change. If you have contacts in the industry, suggest they do this as a kit.
I welded my manifold and then used JB weld on the part I couldnt get too. Still good after 3 years. Heated up the part with a torch and used a mig welder
I put the Blue Devil rear main seal stop leak in my Jeep and it hasnt leaked since and that was over 2 years ago. I was surprised it actually worked. I have 333,587 miles on my 04 Jeep Grand Cherokee limited edition WJ and so far that is the only major problem I had. I guess I've been lucky.
My 99 wrangler bought new is past 194K and but for a fuel pump and a TPS, zero problems. My 91 Comanche also had the 4.0 and that wonderful example of American Iron tragically and suddenly died 800 miles from home ...with 234K on the odometer: RIP, faithful friend.
Have 2000 TJ 4L 130k miles on it, exhaust manifold is not cracked. I like the idea of the flex pipe, good upgrade when I replace exhaust manifold gasket. Replace rear main and trans shifter seal fixed all leaks.
Your manifold will probably never crack. Chrysler upgraded the 4.0 manifolds in ‘99 (I think) by changing to a 2 piece manifold, split front and rear. Your TJ should have the updated manifold. The real fix for the cracking manifold issue is to buy a 2000 or newer 4.0!
I have had a few jeeps with 4.0L's. I have never been able to kill one myself. Even when I did a 3rd gear burnout in my 89 Comanche with 240,000 miles on it. The only way I have managed to destroy a 4.0 is let the wife drive it. I have lost two 4.0L that way....lol 🤣
The thing about the wife is so true! I have a Grand Prix GT with a 3800 motor (another awesome motor) that was just under 200,000 but ran beautifully and drove like a dream. I let my wife drive it for 4 months and now its sitting in the driveway and won't start! You gotta do a LITTLE more than just put gas in em. I'm trying to teach her about how even the best cars need a lil love. lol
ain't that the truth. Lent my mom's the 95 jeep, For a week she drove it with no oil, or very low oil. Probably none by the end of it cause she burns some I think. Still kicking tho, Just turned over 250k miles.
A lot of the leaks I've encountered are from improper installation of seals (or just worn out). For example, my thermosrat housing leaked and when I pulled it off the gasket was buried in some rtv mess and the thermosrat was cock-eyed. Upon further inspection, the housing itself was also warped. Resurfacing the housing, cleaning everything up really well, and torqueing to proper spec has left me with a thermostat that doesn't leak. No RTV needed, just a new felpro paper gasket. I can see why a mechanic wouldn't want to spend that extra time though.
I've owned two XJ, a 1990 and my present ride a 2001 both 4.0. I have had lifter talk in both of them. It seems that only one lifter partially collapses at a time and is intermittent. I tried everything; oil flush, transmission fluid (great cleaner - don't driveway run for to long), all type of different engine oils, viscosity's, additives, graphite additive, synthetics on and on. A coworker suggested AMSOIL synthetic. It cost an arm, leg, and my kids college tuition. I was blown away after a couple of months, no more collapsing lifter. Did I just luck out. Is it a quirk? IDK. I still have the other engine noises that seem to be a part of the 4.0 inline six engine character, and personally I wouldn't have it any other way. Happy times.
mine makes that clicking sound too, replaced 3 pistons from a junkyard engine when number one wrist pin really loosened up and made a racket, found the narrow piston rings all seem to get stuck in the pistons but that was years ago, good since the replacements. basically a reliable engine
@@joeray5394 thanks joe. I hooked a mechanical gauge up to it years ago. The low readings and pressure drop were confirmed. I just kept driving it and figured if it died I'd get a reman.
I have an '02 GC 4.0L with ~160K on the clock, the engine still purrs. My only issue has been slow oil leaks, never enough to leave a puddle in the driveway but on bottom of engine it seems to get on everything and when it hits the exhaust its stinky oil burn smell so I clean it every so often. I always figured it might be the main seal, thanks for the video.
The low frequency rattle/knocking sound is piston slap. Valve train rattle is common among in-line sixes of many makes - especially Mercedes Benz. So, if you have a 4.0, you're in good company. As to piston slap: Chrysler went nuts early on and sent teams out to tear down engines in an attempt to isolate and define the noise. No design issues were found, and they reported that piston slap was the cause - which is because the pistons have relatively short skirts,possibly causing the piston to wiggle within the cylinder as it travels up and down. This is a low RPM issue, and goes away when throttling up, which tightens the entire power train. It is normally not audible when throttling down suddenly - like rod knock is. Once the curb idle is reached, the slap returns. It's just a lazy thing. Rarely is there any premature cyclinder wall wear, but the piston skirts SOMETIMES will wear to a point where SOME can chip or break off, ending up harmlessly in the sump. I can't remember if the AMC built 258 did this. I do remember plenty of CJ's and Eagles with lots of valve train clacking. ....and plenty of 280SL Mercedes doing the same. Even my 1978 280Z had valve noise brand new, but performed flawlessly. In-line engines are noisy. They have very long connecting parts compared to V engines.
I had the crack manifold way back in 02 got a quality set of extractors , new pipes and muffler! All up cost was less than a OEM manifold !! No shit !! it is still good today ! As for lifters ticking, try 15w40 DIESEL oil I have used it for last 15 years or so Higher zinc content loved by flat tappets ! Another thing is if you have all the symptoms of a bad o2 sensor upstream- unplug it and run it for a week or so ? Sure it runs rich as hell but I never got around to removing it and plugged it in again and runs great with no symptoms ??? Next is coolant sensor-- give similar symptoms? No rattles as yet and approaching 500,000 kilometres -Two other mods for long life? Big alloy radiator, and transmission cooler! I live in Australia's north , unlike Florida we have real crocs !!!
That was a really good 👍 information thanks ..... I have a question about the lifters my xj got overheated and I am doing little overhaul, new pistons, valves, timing chain. .. can I re used the lifters after cleaning them?
I PMed you on facebook looking for an opinion on this 00’s Cherokee I’m looking at, sorry I’m advance if you don’t like that sort of thing, I didn’t know so I took a shot. Great videos🤘🏼
Mine is a 2003 and I have no problems with it except a TPS check engine light for the last 6 years. Doesn't make noise or leak. Of course I don't abuse it either. That might help.
this comment compelled me to mention getting to 390,000 original ," me & wife" miles . It just recently rolled over to that on odometer of our ❤️, the '95 XJ UpCountry which we still drive .
@@MiguelGarcia-vj7oo The vehicle had 160K when I bought it and I treated it poorly. I loaned it to a friend for a year and one day, it blew a hole in the side of the engine. New engine should last a whole lot longer since I am taking much better care of it and nobody gets it but me. Everything that breaks is an opportunity for an upgrade!
High quality oil pump, always keep the oil clean, good filter and you're good to go. 35 psi or better at idle hot, plus 10 psi for every 1000 rpm is a good standard.
I recomend to use about a little less then the half of a quarter lucas gear oil for every oil change and add it up after adding the regular oil it really make this 4.0 engines to run very smooth i used this lucas gear oil with all my vehicles and it really helps the engines.
I just bought a lifted 2001 xj a few days ago. Guy told me it had a sticky lifter and I believe that’s the ticking that I hear. Anyone ever experience valve tick or is this perfectly normal since it’s just a rowdy large old school motor
Ronnie, just like the 84-01 jeep cherokee, you Sir, kick unlimited amounts of a$$!!! I've owned 9 jeeps myself so far and they are the best vehicles in this age of PLANNED OBSOLESCENCE!!!!
Really never new AMC built tractors the first use of 232 inline 6 that I no of was 1958 rambler wagon it was increased to 242 in the early 80's when it went was put in jeep
You did not manchion about the freeze out plugs or casting outlets plugs this is a big problem mostly on hi output motors after 91 You are right on with the piston skits
Hey Cherokee Ronnie. Thx for this vid. By the way...Where do you source your solid motor mounts for the 4.0? I need motor mounts for a 95 zj and figured Id get the transmission mount done as well. Amazon has Ancher brand mounts that they say are OE at a good price point. Any suggestions?
For those who doesn't have the 4.0L, straight 6 yet, real main seal is probably the most common issues that almost all I6 engines will have. This is a design issue and not much can be done. WRT oil filter adapter leak, not all 4.0L have this components to leak to begin with. Also mine had 187K miles and it did not leak. Changing the O rings is not hard but does require some brute force and ability to access tight space. I would keep the adapter though as it is there to have the filter clear the engine mount. Lastly the CPS, can be approached from below by lowering the transmission end and tilting the drivetrain, makes the job so much doable. HTH -DDTJ
@B. RD you don’t know shit about the AMC 4.0 if you think it’s a shit motor. VERY well known for 300k plus miles. New jeep is shit. Old Jeep WAS the shit.
Hey Ronnie.. I have a '99 XJ that Wonders at highway speed.. I've installed a new Steering System.. Also new Lower Control Arms.. Ball Joints.. Everything and it still Wonder.. Help..! Thanks.. Joe
Me too!!! I also have a 99 that wanders. I have replaced EVERYTHING in the steering and still it wanders. I even put “the cure” on the the drag link to stop tie rod roll with no noticeable difference. Help?
Me too!! Lol a 99 XJ. Its the only thing I cant fix. Pretty much everthing is good besides a pull to the right and wonders down the road. 132,000 miles 2 1/2 inch lift and 33 inch tires. Was like that when I got it. Has lots of new parts like steering box, pump, and track bar
I have a 02 TJ that has wandered ever since I bought it. I have replaced all of the suspension bushings, yes all of them, and it still wanders although not as bad. The only thing I haven’t done is ball joints although they don’t seem to be worn excessively.
Hay Ronnie great videos. Got a problem with my 96 grand cherokee 4.0 power steering. There isn't any. My pump is new but on the old pump I have round cylinder that comes to a Y with eletrical connector then the high psi line on the other side. Haven't seen any other jeep that has this. This has got to be the problem since my pump is new and the gear box is only a year old and still no power steering. Can't find any info on it. Hate to have to take it to jeep and get bent over by them. So have you ever seen this on any jeep before? It's one heck of a work out driving with no PS with 36" tires.
Hello Ronnie I'm a current owner of fourv4.0s.. 2 of them have coil packs. 1991 XJ still running strong at 445,211 mi. 98 ZJ 4.0 running great at 98,000 mi. My 2001 XJ has 187,000 mi running fine still.. I'm 2 weeks into my "new" 2004 WJ with the 4.0 185,000, so far so good. I keep hearing that all coil pack equipped 4.0s are junk and were made with different inferior designed blocks and heads than older models. What is your opinion on them ? Thx in advance, I know you're swamped with questions..
If your 4.0 has a tick try Restore next oil change i promise you it'll be silent for 2k miles before it starts ticking again. I'm overdue for new lifters and rocker arms at 247k and I'm 95%sure that's all It is in my 04 wj. Got a little metal in the top end so I believe the rocker arms are worn out. Also try running concentrated ZDDP additive since it has flat tappet lifters it's almost necessary for a quiet motor
I have a 98 xj with a 3 inch coil hood. It works amazing. Any amount of airflow thru the engine bay makes a huge difference. I live in hot humid central florida and i can spend all day creepin and it never gets over 210. Even with the ac blowing all day. All stock cooling system besidea a zj clutch on the fan.
Have a 4.7 stroker in my YJ (built from a 4.0)and I did the following to cool it.Hood louvers (big help)Drill three 1/4 inch holes in thermostat (an old racers trick), Aluminum cross flow radiator with black magic fan with adjustable thermostat, Hesco water pump with improved impeller and hoged out water neck.Also built a air duct below bumper to bring in more air into radiator.(grill area on YJ is too small) Only problem now is heat not so good in winter as it only runs at 160 degrees so I adjust the fan control up a bit and block off air duct. But on a hot summer day it will never go above 190.Before all this it would hit 220 .I also run Evans coolant which contains no water so it can't boil over .Good luck.
I have a 2000 Cherokee with a 4.0. It runs like a dream but once in a while when it's warm I'll stop and do. Some shopping or another chore. When I starts the warm engine it will barely run. I can nurse it to the road and within half a block it's running great again. It's not every time and has been driving me up the wall. Of course when I bring it to a shop they will even sometimes keep it for a few days but never have a problem.. I've replaced almost everything but cannot find the problem. Any ideas????
Injectors toward front of engine tend to heat soak after sitting after running on bot day. Wrap with some insulation individually and see if that works.
I have '89 cherokee 4dr w/ a mishimoto radiator, flowkooler waterpump 160 degree thermostat & it still overheats , i'm thinking switching to the 3 fan setup & an aftermarket oil cooler. Try a pacesetter 3 pc header mine hasn't cracked in 15,000 miles
4.0s are very sensitive to third party radiators. They only like OEM. Luckily Mopar started to make them again. A bad clutch fan can also cause overheating.
Is there a WJ 4.0 with a cracked exhaust manifold? Chrysler upgraded the manifold to a split/2-piece unit starting in the 1999 WJ and in 2000 for the TJ and XJ. As far as I know, buying a post-2000 4.0 is the only real fix for the cracked manifold.
I didn't know about that last part man goddamn I mean my jeeps both 4.0 are pretty loud only because my exhaust stops at the cat but they don't make any crazy noises they run great I've been told for years you can't blow these damn things up so I'm surprised they could do something like that
I own 3 Jeep's a CJ,XJ and ZJ and none of them have had the problems you have had... maybe it's just the driver and not the vehicle...all my Jeep's are meticulously maintained and serviced on a regular basis. My CJ5 had the 4.2l in it and has well over 200k miles on since 75 and the engine is the original motor for that vehicle. My XJ has the 4.0HO with 400k on it with it's original motor, transmission, transfer and axles...the motor has a slide knock to it when it first starts up and goes away as soon as it is started. The ZJwith the 4.0l has just turned over 200k miles on it and just this past weekend I replaced the rear main seal cause it looked like it was starting to leak, other then that...none of my Jeep's have had any of the issue you have had or listed as common issues
Ronnie, I unclamped the upper and lower radiator trans oil steel lines from the transmission's 3/8 rubber lines they clamp on to, so that I can install new trans oil cooler lines. I did not take note which they connect back to. the top steel line or the bottom steel line(that have the 3.8 rubber lines., can you help a girl out?
If you're 4.0 ain't leaking, you're out of oil. Lol
I usually add a quart a month, and for some reason the oil level didn't go down in a few months on the stick and that's when I got nervous lol
@@ericaasen4512 interesting. Did you add an kind of sealer or different oil?
@@commanderdan2319 no, I don't get it, it got pretty hot a few times, maybe the metal heated and melded a bit, or the older oil started thickening enough it cant get through. I'll find out when I do an oil change soon
@@ericaasen4512 I would say more likely the latter than the former. And is your aux fan working? It might explain why the engine is running hot.
My 04 wrangler 70k miles no leaks non of these issues 🤷♂️
My main seal leak comes and goes, kind of like a period but for Jeep’s LOL
Wait that’s exactly what’s happening to me and when it leaks it’s only a couple drops
Way i see it, the slight rear main leak on mine keeps the underside well-oiled as a natural defense mechanism to northeastern rust 🤣
Just means theres oil in it😂
So true. Mine leaked since I got it but decided it didn't want to leak anymore like 2 months ago. I guess she just needs a maxi pad
Replaced my crank sensor in 10 minutes with two long extensions an a swivel an a magnet for the bolts good vid!
What's best way 2004 grand cherokee 4.0 crank sensor top or bottom?
I replace it in 5 with a custom wrench built by me
@@JacobEcret Show off
@@trplpwr1038 I got one better for ya, I change it from the top. Ooooo
@@JacobEcret Smart &&&
452,000 miles on my 2004 4.0, all original, and runs like a top
Me and my gf's dad both rebuilt our jeep motors a half year apart and they're both leaking out the rear main seals now. Its comforting knowing many others share this problem.
Yeah very common
I have a 2000 XJ, 275000+ miles. Just replaced the cylinder head gasket, other gaskets and head bolts. Yeah it's loud. It's getting 16mpg/city before the gasket changes. Great video!!
Thank you! After getting a second opinion from a mechanic, I've learned my valve cover gasket (a few hundred) and not my head gasket needs replacement (5k per now previous mechanic, grrr). Your video gave me some other insights I didn't have but need to have. I love my 94 Cherokee Sport 2 door 4 liter and have been driving it for 25 years and plan on continuing. Was here to learn and I did! Much obliged.
I have a 2004 Jeep Grand Cherokee 4.0 liter.. I am the original owner with over 201k miles it and no blow up thank God😄YES you have to maintain them as in any other vehicle and for those driving off road even MORE SO., I don't take my Jeep off road. I just changed out original thermostat and water pump this past Thursday due to water pump gasket. Over all I think the 4.0 is one of the easiest engines on can work on, Love ❤️ it...
Great video brother. I have had a few 4.0 and argue with the world that the 4.0 has no problems. I agree most are easy fixes as long as the exhaust bolts don’t snap. I also had a head crack too but easy to work on motor and plenty of parts.
Easiest motor to work on
I'm sitting on a XJ, ZJ and a WJ. All 3 get driven on a regular bases except for the zj that stays in the garage when the snow flies Only problem I have so far is the engine noise. It goes away in the zj after it warms up. Makes noise in the wj after it warms up and never goes away in the xj. Great motors been a fan since I got the xj and been adding ever since.
I bought my new 1998 Grand Cherokee (4.0L) brand new. Still own and drive it. Never experienced any of these problems except a tiny leak in the rear main seal. It doesn't leak enough to worry about. The engine oil level never changes. I never had to add any oil between oil changes.
As for noise. the 4.0 is a very quiet engine. It runs very smoothly. You should hear the noises in my 2016 4 Runner! It's been making very loud tapping noise since new. Toyota says it's normal. I sure hope this thing is as reliable as my Jeep. I used to have a 2010 Tacoma. It was full of problems. The engine sounded like an old diesel, at idle with AC turned on. Again. Toyota said it was normal. Manual transmission and the clutch was a disaster (grinding shifts). Throw out bearings had to be replaced 3 times within 60k miles I'd owned it. Sold that piece of sh*t. FYI: I did nothing but oil changes and routine maintenance with my Jeep in the 23 years I've owned it! I did use it for 4 wheeling in Arizona mountains quite a bit and towed a 2 ton travel trailer a lot with it.
Haha I have all these problems but God I still love it. All things I'm working on. Your videos will help, Thanks. 👍
Yup got all these noises both from engine and transmission. It been bothering me for a while. But I do like that sound of clanking that sound like a diesel. I will keep it that way. Adds character
Ah yes, the excitement of playing the next game of wtf is that noise/vibration/smell from my Jeep
I have grown quite fond of the AMC rattle. It has been a companion of mine for many, years.
A couple things I’ve taken away from my 4 years into 4.0s
As long as there well lubricated and have some sort of heat absorption they’ll do just fine my 4.0 has a little tick but it’s not a bad tick same with my AW4 as long as it isn’t over heating and as long as it has some sort of fluid in it you’ll be just fine
Hows she running now?
The only major problem I have ever had with a 4.0 was on the wife's grand cherokee ,
#1 piston grenaded but we drove it for a month afterwards
I bought a Jeep Grand Cherokee Laredo for$650.00. it was in sad 😢 shape. It had 240,000 miles on it. My mechanic said it looked like it had never had a tune up. The coil packs were misfiring. I had a crankshaft sensor replaced, both oxygen sensors, some sort of cooling sensors, the thermostat,gas cap, and fuel filter. The old filter weighed a couple pounds compared to the new one which weighed a few ounces. The odd thing is that I can't tell the difference in performance from when I first bought it and after all the repairs. It clatters like the devil when I get on the throttle. It doesn't use any oil. I use royal purple oil and 93 octane gas. I get about 17 mpg. I 💕 love it.
Your just wasting your money with premium 😂
Most common way I’ve seen a 4.0l break is the piston skirt blowing apart. Thing was still running great no misfire just had a knocking noise lol
Don't forget the notorious head crack on the bunch that were machined bad at the plant-hot temps and not keeping up with the cooling system-there you have it-cylinder wall crack resulting in the famous mysterious case of the lowering coolant level.-Whys it down???
I got a exhaust manifold with the flex pipes and still cracked right at the collector! Haha going to weld it back up today and do solid motor mounts hopefully that works!
Ronnie, good video. Any mechanism has some weaknesses. The 4.0L has fairly minor ones, with well-known fixes.
About the longevity of the 4.0L, they are an inline engine. That means the 4.0L has 7 main bearings, while a V8 only has 5 main bearings. This makes the bottom end tougher than V engines. And if the bottom end doesn't blow up, most people will fix the rest.
I have even considered making a front-end bracket for the CPS and put a magnet in the harmonic balancer. That would make them run cooler and be easier to change. If you have contacts in the industry, suggest they do this as a kit.
Quick, concise, informative. Click! Subscribed!
Thanks I am so happy that I found this video I just got my first jeep with the 4.0 and I love it
This cleared up alot of questions I have for my 88 comanche. Thanks
I welded my manifold and then used JB weld on the part I couldnt get too. Still good after 3 years. Heated up the part with a torch and used a mig welder
I put the Blue Devil rear main seal stop leak in my Jeep and it hasnt leaked since and that was over 2 years ago. I was surprised it actually worked. I have 333,587 miles on my 04 Jeep Grand Cherokee limited edition WJ and so far that is the only major problem I had. I guess I've been lucky.
My 99 wrangler bought new is past 194K and but for a fuel pump and a TPS, zero problems. My 91 Comanche also had the 4.0 and that wonderful example of American Iron tragically and suddenly died 800 miles from home ...with 234K on the odometer: RIP, faithful friend.
Have 2000 TJ 4L 130k miles on it, exhaust manifold is not cracked. I like the idea of the flex pipe, good upgrade when I replace exhaust manifold gasket. Replace rear main and trans shifter seal fixed all leaks.
Your manifold will probably never crack. Chrysler upgraded the 4.0 manifolds in ‘99 (I think) by changing to a 2 piece manifold, split front and rear. Your TJ should have the updated manifold. The real fix for the cracking manifold issue is to buy a 2000 or newer 4.0!
I welded a 1/2" nut to a #60 torx bit and that made the oil filter adapter job easy!
Great video, I have the manifold with the flex pipes in it and it still cracked within 5000 miles
I have had a few jeeps with 4.0L's. I have never been able to kill one myself. Even when I did a 3rd gear burnout in my 89 Comanche with 240,000 miles on it. The only way I have managed to destroy a 4.0 is let the wife drive it. I have lost two 4.0L that way....lol 🤣
The thing about the wife is so true! I have a Grand Prix GT with a 3800 motor (another awesome motor) that was just under 200,000 but ran beautifully and drove like a dream. I let my wife drive it for 4 months and now its sitting in the driveway and won't start! You gotta do a LITTLE more than just put gas in em. I'm trying to teach her about how even the best cars need a lil love. lol
ain't that the truth. Lent my mom's the 95 jeep, For a week she drove it with no oil, or very low oil. Probably none by the end of it cause she burns some I think. Still kicking tho, Just turned over 250k miles.
I love my 99 TJ 4.0 with 170k. It lets me know it’s alive!
A lot of the leaks I've encountered are from improper installation of seals (or just worn out). For example, my thermosrat housing leaked and when I pulled it off the gasket was buried in some rtv mess and the thermosrat was cock-eyed. Upon further inspection, the housing itself was also warped.
Resurfacing the housing, cleaning everything up really well, and torqueing to proper spec has left me with a thermostat that doesn't leak. No RTV needed, just a new felpro paper gasket. I can see why a mechanic wouldn't want to spend that extra time though.
I've owned two XJ, a 1990 and my present ride a 2001 both 4.0. I have had lifter talk in both of them. It seems that only one lifter partially collapses at a time and is intermittent. I tried everything; oil flush, transmission fluid (great cleaner - don't driveway run for to long), all type of different engine oils, viscosity's, additives, graphite additive, synthetics on and on. A coworker suggested AMSOIL synthetic. It cost an arm, leg, and my kids college tuition. I was blown away after a couple of months, no more collapsing lifter. Did I just luck out. Is it a quirk? IDK. I still have the other engine noises that seem to be a part of the 4.0 inline six engine character, and personally I wouldn't have it any other way. Happy times.
mine makes that clicking sound too, replaced 3 pistons from a junkyard engine when number one wrist pin really loosened up and made a racket, found the narrow piston rings all seem to get stuck in the pistons but that was years ago, good since the replacements. basically a reliable engine
Sold my 93 XJ with 325k on it. My 01 Grand has 295k and I ain't skeerd.
Bravo, Brotha!!!
Mine sounds really good no clunks... oh shit 😩😂 I will be doing my crank position sensor soon
Good luck bro !!!
We have a 1990, and haven't had any of these problems.
But I did have to replace the whole floor.
My 4.0 made the weird noises you spoke about bit ran very well while I had it
My 2000 TJ has had low oil pressure for the last 12 years. Engine runs great, never had a problem.
Probably a faulty sending unit, the oil pressure is probably just fine if it's lasted that long. 👍
@@joeray5394 thanks joe. I hooked a mechanical gauge up to it years ago. The low readings and pressure drop were confirmed. I just kept driving it and figured if it died I'd get a reman.
@@Patrick-yh3oi Wow that's interesting, glad it worked out 👍
I have an '02 GC 4.0L with ~160K on the clock, the engine still purrs. My only issue has been slow oil leaks, never enough to leave a puddle in the driveway but on bottom of engine it seems to get on everything and when it hits the exhaust its stinky oil burn smell so I clean it every so often. I always figured it might be the main seal, thanks for the video.
One of the best engines ever made
The low frequency rattle/knocking sound is piston slap. Valve train rattle is common among in-line sixes of many makes - especially Mercedes Benz. So, if you have a 4.0, you're in good company.
As to piston slap:
Chrysler went nuts early on and sent teams out to tear down engines in an attempt to isolate and define the noise. No design issues were found, and they reported that piston slap was the cause - which is because the pistons have relatively short skirts,possibly causing the piston to wiggle within the cylinder as it travels up and down.
This is a low RPM issue, and goes away when throttling up, which tightens the entire power train. It is normally not audible when throttling down suddenly - like rod knock is. Once the curb idle is reached, the slap returns. It's just a lazy thing.
Rarely is there any premature cyclinder wall wear, but the piston skirts SOMETIMES will wear to a point where SOME can chip or break off, ending up harmlessly in the sump.
I can't remember if the AMC built 258 did this. I do remember plenty of CJ's and Eagles with lots of valve train clacking. ....and plenty of 280SL Mercedes doing the same. Even my 1978 280Z had valve noise brand new, but performed flawlessly. In-line engines are noisy. They have very long connecting parts compared to V engines.
Installing a flex joint between manifold and exhaust pipe works really well
Got a 91 & 92 4L over 200k . I've replaced radiators and dampers on both . 91 CPS ,92 TS . Regular maintenance.
THE JEEP IS THE HARLEY OF 4 WHEEL DRIVES ;)
And the freeze plugs rust out on the zj 🇺🇸
The headers with the flex bellows in the #1 & 6 pipes CRACK just like the originals do, my Wrangler is on it's third one!
I had the crack manifold way back in 02 got a quality set of extractors , new pipes and muffler! All up cost was less than a OEM manifold !! No shit !! it is still good today ! As for lifters ticking, try 15w40 DIESEL oil I have used it for last 15 years or so Higher zinc content loved by flat tappets ! Another thing is if you have all the symptoms of a bad o2 sensor upstream- unplug it and run it for a week or so ? Sure it runs rich as hell but I never got around to removing it and plugged it in again and runs great with no symptoms ??? Next is coolant sensor-- give similar symptoms? No rattles as yet and approaching 500,000 kilometres -Two other mods for long life? Big alloy radiator, and transmission cooler! I live in Australia's north , unlike Florida we have real crocs !!!
That was a really good 👍 information thanks .....
I have a question about the lifters my xj got overheated and I am doing little overhaul, new pistons, valves, timing chain. .. can I re used the lifters after cleaning them?
I PMed you on facebook looking for an opinion on this 00’s Cherokee I’m looking at, sorry I’m advance if you don’t like that sort of thing, I didn’t know so I took a shot. Great videos🤘🏼
Mine is a 2003 and I have no problems with it except a TPS check engine light for the last 6 years. Doesn't make noise or leak. Of course I don't abuse it either. That might help.
I had the same problem switched to elhanol free it's been gone ever since
I got a light tapping or something on the very first startup of the day until it hits 210 degrees 😅
Rocker arms & pivots.
Mine had 331K before it finally gave up the ghost
So I got another put in to last for another 20 years another 300K
this comment compelled me to mention getting to 390,000 original ," me & wife" miles . It just recently rolled over to that on odometer of our ❤️, the '95 XJ UpCountry which we still drive .
How did yours only last 330k miles??
@@MiguelGarcia-vj7oo The vehicle had 160K when I bought it and I treated it poorly. I loaned it to a friend for a year and one day, it blew a hole in the side of the engine. New engine should last a whole lot longer since I am taking much better care of it and nobody gets it but me. Everything that breaks is an opportunity for an upgrade!
I changed the crank position sensor by inside near the throttle has a hole and under body, two year ago. mine has 160.000Kms now, 2003 WJ Laredo
High quality oil pump, always keep the oil clean, good filter and you're good to go. 35 psi or better at idle hot, plus 10 psi for every 1000 rpm is a good standard.
I recomend to use about a little less then the half of a quarter lucas gear oil for every oil change and add it up after adding the regular oil it really make this 4.0 engines to run very smooth i used this lucas gear oil with all my vehicles and it really helps the engines.
I just bought a lifted 2001 xj a few days ago. Guy told me it had a sticky lifter and I believe that’s the ticking that I hear. Anyone ever experience valve tick or is this perfectly normal since it’s just a rowdy large old school motor
Updated: motor seized check for piston ring degradation if ticking don’t go away
@@jackpistone8015 Oh damn!
I thought I was crazy especially when you said they sound like diesels but I still like the engine even if they sound like diesels
My 2000 wj 4.0 sounds like a diesel
Just rebuilt my 4.0 had the piston skirt in cylinder 4 split just finishing it up now
my 4.0 literally has every one of these problems, just changed the crank sensor last summer.
I’m not a mechanic and was warned that changing the crankshaft sensor could be a pain. I found out the hard fucking way. Never again !!!
@@scatdog1 go from the top, so easy. I have flex head rachet wrench.
Ronnie, just like the 84-01 jeep cherokee, you Sir, kick unlimited amounts of a$$!!! I've owned 9 jeeps myself so far and they are the best vehicles in this age of PLANNED OBSOLESCENCE!!!!
The 4.0 was originally made for farm tractors. In 20 yearsy 4.0 has never let me down. Easy to work on too.
Really never new AMC built tractors the first use of 232 inline 6 that I no of was 1958 rambler wagon it was increased to 242 in the early 80's when it went was put in jeep
What oil leak? Are you taking about the XJ’s rust prevention system.
You did not manchion about the freeze out plugs or casting outlets plugs this is a big problem mostly on hi output motors after 91
You are right on with the piston skits
A jeep leaking is a good thing... that’s how you know there’s fluids in it! (YJ4LIFE)
I had to replace the crack position sensor, mass airflow and throttle body position sensor about a year ago.
4.0 with a mass airflow sensor?
@@markcarpenter3600 yes, it's right underneath the throttle body
4.0’s dont have a MAF sensor
MAP sensor?
Hey Cherokee Ronnie. Thx for this vid. By the way...Where do you source your solid motor mounts for the 4.0? I need motor mounts for a 95 zj and figured Id get the transmission mount done as well. Amazon has Ancher brand mounts that they say are OE at a good price point. Any suggestions?
4 wheel parts has nice motor mounts for the zj get a stock tranny mount
DB Metalworx have the best mounts for the ZJ
For those who doesn't have the 4.0L, straight 6 yet, real main seal is probably the most common issues that almost all I6 engines will have. This is a design issue and not much can be done.
WRT oil filter adapter leak, not all 4.0L have this components to leak to begin with. Also mine had 187K miles and it did not leak. Changing the O rings is not hard but does require some brute force and ability to access tight space. I would keep the adapter though as it is there to have the filter clear the engine mount.
Lastly the CPS, can be approached from below by lowering the transmission end and tilting the drivetrain, makes the job so much doable. HTH -DDTJ
Mine sounds like a Diesel and has been for years but runs great 141,000 miles still going strong
@B. RD 240k on mine, never spent more than $300 on a fix.
@B. RD you don’t know shit about the AMC 4.0 if you think it’s a shit motor. VERY well known for 300k plus miles. New jeep is shit. Old Jeep WAS the shit.
I've heard that to quite down valve train ticking you can take and run diesel oil in em.
Yes sir I have a whole video on it
yup
I've bought 3 Jeep ZJ's with no start issues. I threw in a $100 Mopar CPS and drove all 3 of them another 100,000 miles.
Love my 4.0 an I have a 90 MJ an a 91 XJ
Hey Ronnie..
I have a '99 XJ that Wonders at highway speed..
I've installed a new Steering System..
Also new Lower Control Arms..
Ball Joints..
Everything and it still Wonder..
Help..!
Thanks.. Joe
Me too!!! I also have a 99 that wanders. I have replaced EVERYTHING in the steering and still it wanders. I even put “the cure” on the the drag link to stop tie rod roll with no noticeable difference. Help?
Me too!! Lol a 99 XJ. Its the only thing I cant fix. Pretty much everthing is good besides a pull to the right and wonders down the road. 132,000 miles 2 1/2 inch lift and 33 inch tires. Was like that when I got it. Has lots of new parts like steering box, pump, and track bar
I have a 02 TJ that has wandered ever since I bought it. I have replaced all of the suspension bushings, yes all of them, and it still wanders although not as bad. The only thing I haven’t done is ball joints although they don’t seem to be worn excessively.
I just replaced the RMS , oil filter housing seals ( original ) and transmission pan gasket last week on my 90 ...no more oil on the garage floor
OH how true.. And vacuum leaks.
I spotted a 99 Jeep Cherokee sport with the 4L I6. It has 197k miles. I'm considering getting it. It's a 1 owner.
I got super lucky my 2000 TJ with 260,000 had a 4.0 that runs as quiet as a fan
Got 261k on mine 👍🏽
I bought a 178k super clean tj but I keel 2nd guessing how long I'm gunna have a running engine for. Does sound like a diesel with the ticking sound.
Hay Ronnie great videos. Got a problem with my 96 grand cherokee 4.0 power steering. There isn't any. My pump is new but on the old pump I have round cylinder that comes to a Y with eletrical connector then the high psi line on the other side. Haven't seen any other jeep that has this. This has got to be the problem since my pump is new and the gear box is only a year old and still no power steering. Can't find any info on it. Hate to have to take it to jeep and get bent over by them. So have you ever seen this on any jeep before? It's one heck of a work out driving with no PS with 36" tires.
Crank sensor. Replaced 3 on mine. Only replaced the manifold once.
We just got a 91 jeep. Lorado 245 thousand miles still runs. Down the highway
What do you mean by a quiet 4.0
LMAO. I was gonna comment the same thing. Mine rattles and clunks, but I'll be damned if she doesn't start every single time.
You can stand a coin on mine. Its smooth as silk.
@@Jack-tx2ve mine can make a coin dance, when the AC's on. But it's still running well and all the fluids look great.
The 4.0 has plenty of issues, they just aren't fatal issues. Saying that as the proud owner of '95 with 312K miles on the clock, it just doesn't die.
Hello Ronnie I'm a current owner of fourv4.0s.. 2 of them have coil packs. 1991 XJ still running strong at 445,211 mi. 98 ZJ 4.0 running great at 98,000 mi. My 2001 XJ has 187,000 mi running fine still.. I'm 2 weeks into my "new" 2004 WJ with the 4.0 185,000, so far so good. I keep hearing that all coil pack equipped 4.0s are junk and were made with different inferior designed blocks and heads than older models. What is your opinion on them ? Thx in advance, I know you're swamped with questions..
They are okay I know the newer 4.0 aren’t has tough but where I come from we beat on the pretty hard
If your 4.0 has a tick try Restore next oil change i promise you it'll be silent for 2k miles before it starts ticking again. I'm overdue for new lifters and rocker arms at 247k and I'm 95%sure that's all It is in my 04 wj. Got a little metal in the top end so I believe the rocker arms are worn out. Also try running concentrated ZDDP additive since it has flat tappet lifters it's almost necessary for a quiet motor
Speaking of leaks, any, any chance leaking rear engine freeze plugs cause coolant in oil.
Thats true my 4.0 sounds like diesel my coworkers always ask me if it has a diesel engine 😂🤦♂️
My oil filter adapter blew out the other day
Ronnie what do you think about a hood scoop to get more air to the engine?
I have a 98 xj with a 3 inch coil hood. It works amazing. Any amount of airflow thru the engine bay makes a huge difference. I live in hot humid central florida and i can spend all day creepin and it never gets over 210. Even with the ac blowing all day. All stock cooling system besidea a zj clutch on the fan.
Have a 4.7 stroker in my YJ (built from a 4.0)and I did the following to cool it.Hood louvers (big help)Drill three 1/4 inch holes in thermostat (an old racers trick), Aluminum cross flow radiator with black magic fan with adjustable thermostat, Hesco water pump with improved impeller and hoged out water neck.Also built a air duct below bumper to bring in more air into radiator.(grill area on YJ is too small) Only problem now is heat not so good in winter as it only runs at 160 degrees so I adjust the fan control up a bit and block off air duct. But on a hot summer day it will never go above 190.Before all this it would hit 220 .I also run Evans coolant which contains no water so it can't boil over .Good luck.
mine has 258k miles the 4.0 grand cherokee, honestly 0 problems besides my serpentine belt and my water pump gasket but other than that perfect
I have a 2000 Cherokee with a 4.0. It runs like a dream but once in a while when it's warm I'll stop and do. Some shopping or another chore. When I starts the warm engine it will barely run. I can nurse it to the road and within half a block it's running great again. It's not every time and has been driving me up the wall. Of course when I bring it to a shop they will even sometimes keep it for a few days but never have a problem.. I've replaced almost everything but cannot find the problem. Any ideas????
Ecu
Injectors toward front of engine tend to heat soak after sitting after running on bot day. Wrap with some insulation individually and see if that works.
It’s heat soak
I have '89 cherokee 4dr w/ a mishimoto radiator, flowkooler waterpump 160 degree thermostat & it still overheats , i'm thinking switching to the 3 fan setup & an aftermarket oil cooler. Try a pacesetter 3 pc header mine hasn't cracked in 15,000 miles
4.0s are very sensitive to third party radiators. They only like OEM. Luckily Mopar started to make them again. A bad clutch fan can also cause overheating.
Is there a WJ 4.0 with a cracked exhaust manifold? Chrysler upgraded the manifold to a split/2-piece unit starting in the 1999 WJ and in 2000 for the TJ and XJ. As far as I know, buying a post-2000 4.0 is the only real fix for the cracked manifold.
I didn't know about that last part man goddamn I mean my jeeps both 4.0 are pretty loud only because my exhaust stops at the cat but they don't make any crazy noises they run great I've been told for years you can't blow these damn things up so I'm surprised they could do something like that
The jeep wobble is another one. I had one and it scared the crap out of me
my 92 valve cover leaks. 200,000 miles
I subscribed cause of your shirt!
Your content is great too, so thanks for that too!
Dont forget about the back hatch always having issues until you cant open it anymore 😂
I own 3 Jeep's a CJ,XJ and ZJ and none of them have had the problems you have had... maybe it's just the driver and not the vehicle...all my Jeep's are meticulously maintained and serviced on a regular basis. My CJ5 had the 4.2l in it and has well over 200k miles on since 75 and the engine is the original motor for that vehicle. My XJ has the 4.0HO with 400k on it with it's original motor, transmission, transfer and axles...the motor has a slide knock to it when it first starts up and goes away as soon as it is started. The ZJwith the 4.0l has just turned over 200k miles on it and just this past weekend I replaced the rear main seal cause it looked like it was starting to leak, other then that...none of my Jeep's have had any of the issue you have had or listed as common issues
You want a cookie? 🍪
Ronnie, I unclamped the upper and lower radiator trans oil steel lines from the transmission's 3/8 rubber lines they clamp on to, so that I can install new trans oil cooler lines. I did not take note which they connect back to. the top steel line or the bottom steel line(that have the 3.8 rubber lines., can you help a girl out?