The washing of the cylinders by gasoline could have been caused by multiple Issues for example it could have had a bad fuel injector that staying open it could have a bad fuel pressure regulator..These 4.0 engines are also known for having oiling issues on cylinder #6 my dad has blown up 2 of these engines and both cylinder 6s were ran Without oil somehow I think it's just the bad design of this engine or a flaw perhaps in the oiling ...?
Port injected, so a stuck injector would only wash one cylinder...and a bad coolant temp sensor would not have fed this volume of gas to the engine. Same with a non functioning pressure regulator (unless the diaphragm is ruptured but then the engine probably wouldn't run for more than a few seconds, and again it would mostly effect the cylinder closest to the vacuum port) A bad MAP will absolutely wash the inside of an engine by hanging the injectors wide open.
@@UncleTonysGarage My 4.0 was over fuelling badly, to the point of diluting the engine oil. Turned out to be a badly cracked exhaust manifold/ header and a bad o2 sensor.
Second on the MAP sensor . My nephew bought an 88 2wd 5 speed the PO got tired of trying to fix . Of course they had no idea WTH they were doing so in true shade tree fashion proceeded to fire multiple broadsides from the parts cannon . None of these parts was a new MAP sensor and half the.lines were disconnected or misrouted . So my nephew gets this heap home and it promptly set the grass under it on fire . The MAP sensor vacuum line was unhooked making the computer believe the engine was at WOT and maxed out the injector duty cycle . All this fuel caused the catalytic converter to overheat . Luckily I had a garden hose handy and spent the next 3 days fixing all the " repairs " done by the PO . After that the thing was as dependable as could be and no more grass fires .
There are some interviews here on RUclips with one of the cylinder head engineers for this engine. He mentioned that the straight 6 was the most profitable engine in Chrysler's history. Part of that profitability was the use of the cheapest cast pistons possible. This engine greatly benefits from a nice set of 4032 forgings or hypereutectics.
Took a class at my local community college where I learned about this process. Was able to dig into a bunch of new engines, and learned a lot of really good stuff. Now I am about to start in on my 1966 Cadillac CDV. Been looking at her in the garage for months, and I do believe the time is near for our relationship to grow =) Thank you or these videos!
on my engine tear downs i will place the bolts back into the holes they come out of. keeps them where they go when you need to put it back together. another time step but pays in the long run.
In high school autoshop, we stamped cylinder numbers on each cap, rod, piston and in such a way we had a reference to not reverse them - they went back in the exact sample places and orientaion. Values were kept in a wooden jig with numbered holes/boxes to hold each valve with their rocker and springs.
I use a sheet of cardboard marked front/back and driver/passenger when I have to keep track of bolts. Just pop them through in order and it's easy to keep track.
^^^ This. Scrap of cardboard, label with felt tip marker, punch holes for bolts, valves, etc. I 'number' pistons and rods using very light 'hash marks' cut with a thin abrasive wheel in a Dremel. *gasp!* On aluminum, light marks with a small chisel work too. Don't make these marks on highly stressed areas, such as connecting rod beams or middle of rod caps. Mark the same areas used for balancing.
Tony, The best auto shop teacher you never had! Lol. Your stuff is wonderful Tony. You instruct but you entertain at the same time. What a great personality. Thanks, Dave
These episodes are released exactly a month behind my first tear down and rebuild process, step for step. Feels like uncle Tony is grading me every step of the way
Hey Tony. Better to sit and watch each step as it comes (even if it is in silence) than to just explain in a general way, without showing the procedure. I much prefer your way, over some others who really don't want to show too much, and seem to like the sound of their own voice. Keep doing good!!!
Just finished tearing my engine apart. Aside from a rust ridge on cylinder 1 it's surprisingly good for sitting open in a junkyard for 6 months. It's so caked in old oil that it protected everything. Even the bearings show minor wear.
It's funny because I even feel like I'm fancy and cheating if I use a speedwrench over a rachet. Haha. Also, with the tapping piston assemblies out, I use the wooden handle end of my ball pein hammer so there's no chance of damage. Granted, now after 33 years, the handle is splintered to hell now. Haha.
Yes exactly. Those rod and caps have to go back on the exact rod and correct direction that they came off. Same with the main bearing caps, put back exactly where and direction they came from. Very important.
I just did a 2.3 Ranger engine that drove into the shop. The piston skirt and rings were laying in the bottom of the pan. Ended up doing a hone job on it and a new set of pistons rings and bearings.
Mine came back from the machine shop like that. Every last cap flattened slightly out of round by the impacts. Very bitter about this even 40 yrs later.
my grandpa always said if you cant fix it with a screw driver, or hammer or a gross of rubbers just fuck it. no my grandpa didnt say that lol actually i was at a ford class and our tech said mechanics are getting lazy and those were the tools for a job if it took any more they wipe there hands of doing the job . i understood where he was coming from blunt and to the point great Tech he was
I saw a trick online that uses a big piece of cardboard for bolts. You take one bolt off at a time and place in the position as they were on. I took a sharpie pen and drew a simple outline or write what the bolt group is for. I use a drill to make a pilot hole quickly before pushing each bolt through the cardboard. Im telling you, its so easy and makes life 1,000 easier when taking things apart and putting back
I like the slow pace of these videos, after 30+ years of only changing out "wear parts" like starters, misc parts, I'm getting ready to attempt my first "rebuild" (Toyota 22r) Plan is same as this, just replace all parts with stock (except cam, to go with the header and Weber/ Offy manifold!)
Looks just like the #3 piston I just replaced on my 97 Cherokee. Everything in the engine looked great. I cleaned everything up put one new piston in it and runs great.
I'm using your playlist to make sure my first build is going on track! 🙏 so its working, i watch everything you make cuz it's honestly the best methods for me
I had an uncle named Tony, he was an ol school gear head like you and he rode a triumph and drove a 60 Impala, he passed away in a car accident as a passenger, RIP T-bone
Snails past is perfect for me. I have time to absorb details that we usualy skip cause we want to eat the dessert already! Nice content uncle Tony again.
I recently replaced the oil pan gasket on my ‘74 Imperial. There was a connecting rod nut laying in the bottom of the pan. Ofcourse none of the nuts on the rods were missing otherwise you would blow the engine. I was atill shocked to find it. This was an all original engine, never been apart.
If you didn't already know, do NOT use a high volume oil pump on a 4 liter. They just don't need the extra volume, and it's very likely to just chew up the cam gear. I've personally had it happen, and I found out after the fact from the machine shop I had do my work that it's super common on 4 liters with HV pumps. Also, I've had 2 of my own 4.0s meet their demise with broken OEM piston skirts.
That’s true for many engines. Common practice is to put HV oil pumps in at overhaul because ‘ it’s better’. Common result was sheared pump driveshafts. Also, burst oil filters was a problem. A standard volume pump is plenty sufficient for street use.
My first American car was a 1964 283 Chevrolet Impala, it had an engine noise which I was told maybe a stuck lifter. I changed the lifters, still the same. Turned out to be a cracked piston, the only thing holding it together was the steel strap cast into the pin boss !.
A thing you could talk about Uncle Tony while you're using that tool is how it feels in your hand and how a guy or gal should be Hands-On while they're tearing apart or put together a motor
Tony your best bet is to swap those Pistons out. What you have is exactly what happened to my friend. Only he just had a wrist pin and a rod left when I took the motor apart. We had to sleeve it to save the block
I can’t say I’ve ever had a one of these 4 liter Jeep engines apart. These things just didn’t die before the jeeps all rusted an half! I’m amazed any of these 4.0 jeeps are still around up here in New England they are all gone thanks to the insane amount of salt they dump on the roads.
Uncle Tony, your advice about mixing up the pistons and rods may turn around and bite someone's back side. one rod journal or cylinder bore may have over sized piston or an undersized rod journal. and if a novice doesn't catch it, he or she can be in a world of hurt. it's always better to put things back where they came from. ESPECIALLY if they are going to reuse some of the parts.
You demonstrated exactly why I never turn the engine upside down until I have first removed the oil pan. This keeps any shrapnel and gack from falling down into the reciprocating assembly.
Tip if you're not going to be sending the block for hot tank or doing anything like that, just use a paint marker and put a small mark where the studs are. This will save you the time of searching for the picture, and then searching for where they are.
It's a pretty thin piece, so it probably stands a better chance of receiving immediately visible damage, than its surroundings in that scenario. What I want to see is the broke-off piece held up to its spot on that #6 piston. I'll bet that it no longer fits like a glove...
I would have liked to see if that last main girdle bolt was as tight before removing all of the rest. Ive always thought that you want to remove main bolts in reverse order. No shade just admiration/curiosity. You have created a great channel with copious and easily digested info as well as what looks to be a kickass life brother! Keep up the good work!
on the egine i rebuilt got became a stroker. But keep an eye on the push rods lenths ( they where all different lenths on mine) so I put in an adjustable rocker arm kit.
Tony: “Judging by the general condition of this, I’m gonna say that this engine had a bad MAP sensor” Me: “you know I was just thinking the same thing” Not hating, Im just remind of why I’m here: UT knows his shit
The piston skirts are super common on the 4Ls. I had the same issue with my 2002 wrangler. instead of putting the 4L back we put in a 5.2L magnum. using the bell housing from a 3.9L magnum we could mount it to the jeep trans.
@@carlt6932 Its fuel injected. As long as you end up with the right computer the body and chassis harness is plug and play! even the factory gauges work properly.
Uncle Tony i wish I had these videos when I was a teenager pulling engines out in my mother's driveway . I'm 49 now and my fear is there's generations of kids who can't open a car hood .
Map sensor or maybe the thermostat was stuck open for a really long time. That can cause an injected motor to go rich.... Or maybe the coolant temp sensor.
Tony, another good vid as usual. I wondered if, maybe for next update or maybe a separate spin-off upload (if you think it would be too off the spirit of 1st engine job theme) you could grab one set of main cap, main brg, rod cap, rod brg, & crank from one of the open late model cast crank 225 slant6s that you have laying around to compare with those on that 4.0L-Jeep inline6. Not to try to suggest that 7 main brg design is in some ways better than 4 main brg design (or visa-versa), but to see how it affects things like: general shape/layout of crank, crank cheeks, counterweights, block main webs, crank crankcase, overall crank length, weight, overall engine length, etc. Also I'm not trying to troll or upset any loyal Jeep folks, after all we're still both under the same Ma Mopar banner aren't we?
When I see the filings in the oil pan I wonder if it's worth while to set a cow magnet in the oil pan to grab metal and keep it from circulating through again and again.. Did you happen to do a compression test on this engine? It would be interesting to know where each cylinder was at.
I run a magnetic drain plug and noticed a new timing chain set (cast gear vs oem nylon) sluffed and an minor afro accumulated on the magnet for a while. I want to begin using my cheap boroscope through the drain plug, don't expect to find anything but ya' never know if you don't look.
Gotcha beat...... Pulled the pistons out of 351 Windsor with unknown millions of miles on it. One of the piston skirts was broken but the piece was still trapped by the angle of the fracture holding it against the cylinder wall and just following the piston in its travels up and down. It had been that way for so long the edges of the fracture were beginning to smooth out. The piece didn't fall out until I drove the piston out of the cylinder......Weirdest thing I had ever seen.
All those Mopar/AMC Jeep inline 6 engines ran rich as Hell with that MAP sensor set up and carbon covered everything because of it plus caused rings to stick and oil to blow all over the place. They still ran good and forever though.
Unc: Maybe the boys and girls should be reminded to put pieces of fuel hose or those nice plastisol booties by Michigan or Clevitel on the conrod bolts . I have seen many cranks with the telltale mark of 3 or 4 marks from the conrod bolt threads on the journals.
Between watching this series and David Visard's videos, I'm ready to find a Junkyard engine to build. The LT1 in my 96 Buick Roadmaster sedan has over 170k miles so I know I need to rebuild it. But since I don't have the time, money, or another car to drive. I think getting a complete engine to rebuild would be my best bet. Cause I can't afford any surprises
I have been in the automotive trade for 49 years, and your instruction is spot on. If I make one suggestion, use a section of broom stick to drive the pistons out, some engines will have a pronounced ridge at the top of the bore, and people that haven't done this before may put too much force into removing them. The wood will absorb some of the beating.
I've got a 4.0 litres jeep in my engine shop that ingested a major amount of water and is literally just chunks of shit . My buddy asked if I could salvage the block and crank .I gave him a quote for a tear down , hot tank , magna flux the block and crank , the deck milled after 6 cyl sleeves then the crank work plus a replacement set of rods and the rebuild kit he decided to just get another one from a junk yard for 400.00 bucks 😂
That crack is very fresh like it just happened when you find the missing piece you should be able to research what happen. As somebody commented leaking injector problem.
I think Uncle T got the motor from my old ZJ. Bad water pump on the way home at 2 am, stopped several times to cool it down. Next day, no startie... bummer...
As I watched you remove the #1 piston, I noticed you just pulled it out of the cylinder without preventing the end of the rod possibly scraping the cylinder wall.
Just a thought Uncle Tony, but you might want to cover the steps to clean and check original pistons for the newbies so they get the scoop for re-using them too. My ring groove cleaner made me do this. Love your channel, always good stuff!
Easy on bouncing your rod bolts against the crank especially if you are not going to polish. I try to never tap on rod bolts that are the stud and nut. If they move in the rod often they don't tourqe up round. I have customers do this often when they pull there motor apart and i often have to resize the rods.
Tony it would be cool to see you throw a crank and connecting rods out of a 4.2. Turning this into a 4.6 stroker, as well as cam and some port an polish. I feel there is a lot of untapped potential in these engines nobody knows about
This engine is going together bone stock for my daily driver...the one coming out of that Jeep is a different story. That one is going to get the full treatment and will find its way into a lightened 2WD to see what we can get out of it. It'll be a while before we get to that, but I promise it'll be interesting.
As soon as I saw you pull that broken skirt out I said to myself that has to be #6. I think Chrysler undersized the pistons from the factory, and I just did a quick search and it seems that it's common on 99-2002 and that the castings were bad for those years, but why it happens so often on #5 and #6 I'm not so sure. The girdle is interesting, I personally have an 88 and mine either didn't come with one or was removed.
Kaboom is right on the money. The girdle was a 96+ add on for NVH. As far as #6 popping the skirt, its fairly common when you overheat these blocks, #6 is the hottest running cylinder, due to the path of coolant to it. As far as castings go, thats the head castings. If your head was marked TUPY, it was one of the redesigned heads that fixed the cracked castings due to the coil over plug bosses being too close to the water jacket, Tony's got a distributor ignition engine so he shouldnt have the head issue. Should have the 0621 head on it if my memory serves me correctly.. Tony- your right on the money with the MAP sensor, most likely the vacuum line running from the manifold to the MAP split, and it was getting an atmospheric reading, and the engine went into WOT fueling mode. Had that happen on both the MJ and my 93 XJ once. Usually its the rubber 90 degree fitting that fails. Those rod bearings looked mint though. The old AMC Inline's could take a pounding and keep running. Over-engineering at its finest. Those and the old 300 straight sixes will still be running somehow when the last human is walking the face of the earth lol.
Jeep 4.0's (which also applies to all AMC inline 6's) used letter coded pistons that had generally loose tolerances that varied by a couple ten thousandths of an inch and were selected based on bore diameter to reduce the number of scrapped blocks. That's why OEM Jeep 4.0 have that tell tale noise at idle. A reman motor won't have the noise due to all bore being "equal" and piston matching the diameter. They did the same for rod and main bearings It was common to have different bearing shells top and bottom in both sets of rod and mains to meet tolerance needs. Was a Jeep tech for over 20 years. The "girdle" was added starting in 1996 to combat NVH (noise vibration and harshness) and did stiffen the bottom end a lot. It's a direct fit all you need are the main bolts, girdle and nuts.
@@carllmack2287 So was I, I started working for AMC in late 85 and transitioned into Dodge in 2006. I worked at several dealerships where I was the only Jeep tech. My easy overflow would go the the Ford techs. I remember crank kits with odd size bearings. I thought that was really strange. I remember the MS1700 scanner, in that blue box. It didn’t just read the codes, it tested sensors as it ran through the program. 🤣
The washing of the cylinders by gasoline could have been caused by multiple Issues for example it could have had a bad fuel injector that staying open it could have a bad fuel pressure regulator..These 4.0 engines are also known for having oiling issues on cylinder #6 my dad has blown up 2 of these engines and both cylinder 6s were ran Without oil somehow I think it's just the bad design of this engine or a flaw perhaps in the oiling ...?
Port injected, so a stuck injector would only wash one cylinder...and a bad coolant temp sensor would not have fed this volume of gas to the engine. Same with a non functioning pressure regulator (unless the diaphragm is ruptured but then the engine probably wouldn't run for more than a few seconds, and again it would mostly effect the cylinder closest to the vacuum port) A bad MAP will absolutely wash the inside of an engine by hanging the injectors wide open.
@@UncleTonysGarage My 4.0 was over fuelling badly, to the point of diluting the engine oil. Turned out to be a badly cracked exhaust manifold/ header and a bad o2 sensor.
Second on the MAP sensor .
My nephew bought an 88 2wd 5 speed the PO got tired of trying to fix . Of course they had no idea WTH they were doing so in true shade tree fashion proceeded to fire multiple broadsides from the parts cannon .
None of these parts was a new MAP sensor and half the.lines were disconnected or misrouted .
So my nephew gets this heap home and it promptly set the grass under it on fire .
The MAP sensor vacuum line was unhooked making the computer believe the engine was at WOT and maxed out the injector duty cycle .
All this fuel caused the catalytic converter to overheat .
Luckily I had a garden hose handy and spent the next 3 days fixing all the " repairs " done by the PO .
After that the thing was as dependable as could be and no more grass fires .
Map has a very high priority on fueling.
Why do the rods and caps need to be kept together?
Love the slow pace of these videos. For a guy who knows FA about stuff like this, it's fascinating.
There are some interviews here on RUclips with one of the cylinder head engineers for this engine. He mentioned that the straight 6 was the most profitable engine in Chrysler's history. Part of that profitability was the use of the cheapest cast pistons possible. This engine greatly benefits from a nice set of 4032 forgings or hypereutectics.
Screw the piston dome to a door and use it as a knocker. The missing skirt facing down will allow the rod to swing into the door unobstructed.
Took a class at my local community college where I learned about this process. Was able to dig into a bunch of new engines, and learned a lot of really good stuff. Now I am about to start in on my 1966 Cadillac CDV. Been looking at her in the garage for months, and I do believe the time is near for our relationship to grow =) Thank you or these videos!
An easy trick to not lose parts or fasteners is to minimize the time between tear down and reassembly
The small block chevy sitting in the corner of my shop for the last five years would probably agree with you
I never lose fasteners. I always have extra after the job 😬
on my engine tear downs i will place the bolts back into the holes they come out of. keeps them where they go when you need to put it back together. another time step but pays in the long run.
@@bob8776 i know the pain of that reality
@@erwinnijs1 WOW that can be a problem do you have extra rod bolts ;-)
In high school autoshop, we stamped cylinder numbers on each cap, rod, piston and in such a way we had a reference to not reverse them - they went back in the exact sample places and orientaion. Values were kept in a wooden jig with numbered holes/boxes to hold each valve with their rocker and springs.
I use a sheet of cardboard marked front/back and driver/passenger when I have to keep track of bolts. Just pop them through in order and it's easy to keep track.
When I bag parts on big projects l all ways tag things Driver or pass side.
^^^ This. Scrap of cardboard, label with felt tip marker, punch holes for bolts, valves, etc. I 'number' pistons and rods using very light 'hash marks' cut with a thin abrasive wheel in a Dremel. *gasp!* On aluminum, light marks with a small chisel work too. Don't make these marks on highly stressed areas, such as connecting rod beams or middle of rod caps. Mark the same areas used for balancing.
@oneeyedcat3072 sub to him if you can please
Tony, The best auto shop teacher you never had! Lol. Your stuff is wonderful Tony. You instruct but you entertain at the same time. What a great personality. Thanks, Dave
These episodes are released exactly a month behind my first tear down and rebuild process, step for step. Feels like uncle Tony is grading me every step of the way
Hey Tony. Better to sit and watch each step as it comes (even if it is in silence) than to just explain in a general way, without showing the procedure. I much prefer your way, over some others who really don't want to show too much, and seem to like the sound of their own voice.
Keep doing good!!!
agreed...the suspense of going thru the whole motor & finding the failure
Just finished tearing my engine apart. Aside from a rust ridge on cylinder 1 it's surprisingly good for sitting open in a junkyard for 6 months. It's so caked in old oil that it protected everything. Even the bearings show minor wear.
@oneeyedcat3072 sub to him if you can please
It's funny because I even feel like I'm fancy and cheating if I use a speedwrench over a rachet. Haha. Also, with the tapping piston assemblies out, I use the wooden handle end of my ball pein hammer so there's no chance of damage. Granted, now after 33 years, the handle is splintered to hell now. Haha.
@oneeyedcat3072 sub to him if you can please
I’ve got a very old “ Blue Point” hammer handle that looks the same way.
Definitely not production work. Dealers everything gets blasted on/off with the battery tools to a torque of it stopped
Making a video or group of videos that give a semi detailed instruction to engine tear down, rebuild and reassembly is a daunting task.
There seems to be a lost art these days in using hand tools.
I try to use them when I can as well. Thank you for your content UTG!
Also an exhaust leak before an o2 sensor will read lean and over time will correct by adding fuel washing the cylinders down, good video.
Yes exactly. Those rod and caps have to go back on the exact rod and correct direction that they came off. Same with the main bearing caps, put back exactly where and direction they came from. Very important.
I just did a 2.3 Ranger engine that drove into the shop. The piston skirt and rings were laying in the bottom of the pan. Ended up doing a hone job on it and a new set of pistons rings and bearings.
An alternative to pounding down the pistons is to use a piece of woodstick. Hickory is hard and nice, and will not make any dents regardless.
I usually number stamp my rod caps and main caps. That's was what my grandpa use to do.
Dots with a centre punch.🇨🇦
Mine came back from the machine shop like that. Every last cap flattened slightly out of round by the impacts. Very bitter about this even 40 yrs later.
my grandpa always said if you cant fix it with a screw driver, or hammer or a gross of rubbers just fuck it. no my grandpa didnt say that lol actually i was at a ford class and our tech said mechanics are getting lazy and those were the tools for a job if it took any more they wipe there hands of doing the job . i understood where he was coming from blunt and to the point great Tech he was
YOU TAKE YOUR TIME ! All the time you need !
Valve job, new rings, bearing, new cam with lifters, gaskets, soft pugs, etc ! $500 AND 100,000 MILES! GOOD to go!
I saw a trick online that uses a big piece of cardboard for bolts. You take one bolt off at a time and place in the position as they were on. I took a sharpie pen and drew a simple outline or write what the bolt group is for. I use a drill to make a pilot hole quickly before pushing each bolt through the cardboard. Im telling you, its so easy and makes life 1,000 easier when taking things apart and putting back
I like the slow pace of these videos, after 30+ years of only changing out "wear parts" like starters, misc parts, I'm getting ready to attempt my first "rebuild" (Toyota 22r) Plan is same as this, just replace all parts with stock (except cam, to go with the header and Weber/ Offy manifold!)
Looks just like the #3 piston I just replaced on my 97 Cherokee. Everything in the engine looked great. I cleaned everything up put one new piston in it and runs great.
@oneeyedcat3072 sub to him if you can please
I love the tap on the rod bolt nuts technique to separate the rod cap from the rod thank you
That Craftsman ratchet. The best design ever.
I'm using your playlist to make sure my first build is going on track! 🙏 so its working, i watch everything you make cuz it's honestly the best methods for me
I had an uncle named Tony, he was an ol school gear head like you and he rode a triumph and drove a 60 Impala, he passed away in a car accident as a passenger, RIP T-bone
Number 6 runs hot on the 4.0. I’ve seen a few with broken #6 . A friend just replaced the piston and is still driving it after two years.
Classic case of muffler belt too loose causing the timing regulator to over stimulate the carbinator thus the #6 piston failure.
thank you for this series. i'm new to engine building and owning classic cars. i've found your channel super helpful
Snails past is perfect for me. I have time to absorb details that we usualy skip cause we want to eat the dessert already!
Nice content uncle Tony again.
great content, have a 318 I'll be doing my 1st complete rebuild this summer. This series of yours is perfect. Thanks!
At least that pan doesn't look like a gravel pit... Keep up the good work man. J. (Michigan)
I recently replaced the oil pan gasket on my ‘74 Imperial. There was a connecting rod nut laying in the bottom of the pan. Ofcourse none of the nuts on the rods were missing otherwise you would blow the engine. I was atill shocked to find it. This was an all original engine, never been apart.
Watching a bunch of your videos and its making me really excited to start tearing down and rebuilding my 327.
If you didn't already know, do NOT use a high volume oil pump on a 4 liter. They just don't need the extra volume, and it's very likely to just chew up the cam gear. I've personally had it happen, and I found out after the fact from the machine shop I had do my work that it's super common on 4 liters with HV pumps. Also, I've had 2 of my own 4.0s meet their demise with broken OEM piston skirts.
That’s true for many engines. Common practice is to put HV oil pumps in at overhaul because ‘ it’s better’. Common result was sheared pump driveshafts. Also, burst oil filters was a problem. A standard volume pump is plenty sufficient for street use.
the wire you keep finding could be the spring under the timing cover that keeps the camshaft back
YES!!! The Old School "Speed handle" 👍👍
My first American car was a 1964 283 Chevrolet Impala, it had an engine noise which I was told maybe a stuck lifter.
I changed the lifters, still the same. Turned out to be a cracked piston, the only thing holding it together was the steel strap cast into the pin boss !.
A thing you could talk about Uncle Tony while you're using that tool is how it feels in your hand and how a guy or gal should be Hands-On while they're tearing apart or put together a motor
@oneeyedcat3072 sub to him if you can please
Tony your best bet is to swap those Pistons out. What you have is exactly what happened to my friend. Only he just had a wrist pin and a rod left when I took the motor apart. We had to sleeve it to save the block
I can’t say I’ve ever had a one of these 4 liter Jeep engines apart. These things just didn’t die before the jeeps all rusted an half! I’m amazed any of these 4.0 jeeps are still around up here in New England they are all gone thanks to the insane amount of salt they dump on the roads.
Uncle Tony, your advice about mixing up the pistons and rods may turn around and bite someone's back side. one rod journal or cylinder bore may have over sized piston or an undersized rod journal. and if a novice doesn't catch it, he or she can be in a world of hurt. it's always better to put things back where they came from. ESPECIALLY if they are going to reuse some of the parts.
You demonstrated exactly why I never turn the engine upside down until I have first removed the oil pan. This keeps any shrapnel and gack from falling down into the reciprocating assembly.
What about numbering the rod caps and rods to make sure you get them back on the way they came apart
You can, or just remember the locks always go together when putting the cap back on the rod.
@oneeyedcat3072 sub to him if you can please
Very similar of how I work.. again great conformation that I have been on track with my projects…
Tony's speed wrench......classic ! ...and yes I do own one .
Tip if you're not going to be sending the block for hot tank or doing anything like that, just use a paint marker and put a small mark where the studs are. This will save you the time of searching for the picture, and then searching for where they are.
@oneeyedcat3072 sub to him if you can please
I can't believe that "chunk" came off and dropped into the pan without damaging anything else in the process. 😮
It's a pretty thin piece, so it probably stands a better chance of receiving immediately visible damage, than its surroundings in that scenario.
What I want to see is the broke-off piece held up to its spot on that #6 piston. I'll bet that it no longer fits like a glove...
@oneeyedcat3072 sub to him if you can please
The definition of good fortune, I thought. Small enough to pass into the sump, big enough not to get picked up again.
I admit to getting "antsy" waiting for each episode of this series to appear, but I appreciate that Uncle Tony is taking the time to be thorough.
I appreciate your patience! It's a fine line between overwhelming the channel with one series and keeping the flow moving on this.
I would have liked to see if that last main girdle bolt was as tight before removing all of the rest. Ive always thought that you want to remove main bolts in reverse order.
No shade just admiration/curiosity. You have created a great channel with copious and easily digested info as well as what looks to be a kickass life brother! Keep up the good work!
You're doing God's work, Uncle Tony.
Truly, thank you.
When you said "Just use an airgun !" I laughed. My OCD was saying the exact same thing ! Lol
I like the way you work and operate:) I have a 1997 Cherokee I've had 20 years. Good vehicle:)
Watching you work on that straight 6 make me want to tear down my slant 6.
I've heard of some of those 4.0L Jeep engines lasting upwards of 700k miles.
In states where vehicles don't rust out of course.
Good idea to use sump pan for all the pieces I do the same
Same. I like to "feel" what the bolt or nut does as I remove or tighten.
Reminds me as a kid watching chuck on horsepower tv, he always used a speedwrench every chance he got lol.
on the egine i rebuilt got became a stroker. But keep an eye on the push rods lenths ( they where all different lenths on mine) so I put in an adjustable rocker arm kit.
Tony: “Judging by the general condition of this, I’m gonna say that this engine had a bad MAP sensor”
Me: “you know I was just thinking the same thing”
Not hating, Im just remind of why I’m here: UT knows his shit
Thanks!
Surprised you didn't put hose on the rod bolts so the crank doesn't get nicked....
Just about every 4.0 jeep engine I ever taken apart cylinder 5 or 6 always had a cracked piston skirt. I could never figure out why.
Runs hotter, more stress. Modern cost reduction clashed with the ancient design.
When the check engine light comes on. Sometimes it really really means check the engine.
Especially when the check engine light stops working.
YES!!! Early to a video release!! Thank you for these videos.
@oneeyedcat3072 sub to him if you can please
The piston skirts are super common on the 4Ls. I had the same issue with my 2002 wrangler. instead of putting the 4L back we put in a 5.2L magnum. using the bell housing from a 3.9L magnum we could mount it to the jeep trans.
@@carlt6932 Its fuel injected. As long as you end up with the right computer the body and chassis harness is plug and play! even the factory gauges work properly.
Uncle Tony i wish I had these videos when I was a teenager pulling engines out in my mother's driveway . I'm 49 now and my fear is there's generations of kids who can't open a car hood .
Map sensor or maybe the thermostat was stuck open for a really long time. That can cause an injected motor to go rich.... Or maybe the coolant temp sensor.
I've had many 4.0 jeeps over the last 30 years. Most had a lil piston slap noise.
The Strong’s Garage boys just found an old (house) door hinge pin and a 1976 penny in the oil pan of their Ford Model B oil pan.
These videos are great. Like watching Bob Ross on engines.
No pressure, no pressure you can just rebuild that engine however you you like.
Peace from the fringes of the jersey turnpike.
Everone of these I have done has been number 6
Tony, another good vid as usual. I wondered if, maybe for next update or maybe a separate spin-off upload (if you think it would be too off the spirit of 1st engine job theme) you could grab one set of main cap, main brg, rod cap, rod brg, & crank from one of the open late model cast crank 225 slant6s that you have laying around to compare with those on that 4.0L-Jeep inline6. Not to try to suggest that 7 main brg design is in some ways better than 4 main brg design (or visa-versa), but to see how it affects things like: general shape/layout of crank, crank cheeks, counterweights, block main webs, crank crankcase, overall crank length, weight, overall engine length, etc. Also I'm not trying to troll or upset any loyal Jeep folks, after all we're still both under the same Ma Mopar banner aren't we?
When I see the filings in the oil pan I wonder if it's worth while to set a cow magnet in the oil pan to grab metal and keep it from circulating through again and again.. Did you happen to do a compression test on this engine? It would be interesting to know where each cylinder was at.
I run a magnetic drain plug and noticed a new timing chain set (cast gear vs oem nylon) sluffed and an minor afro accumulated on the magnet for a while.
I want to begin using my cheap boroscope through the drain plug, don't expect to find anything but ya' never know if you don't look.
Gotcha beat...... Pulled the pistons out of 351 Windsor with unknown millions of miles on it. One of the piston skirts was broken but the piece was still trapped by the angle of the fracture holding it against the cylinder wall and just following the piston in its travels up and down. It had been that way for so long the edges of the fracture were beginning to smooth out. The piece didn't fall out until I drove the piston out of the cylinder......Weirdest thing I had ever seen.
All those Mopar/AMC Jeep inline 6 engines ran rich as Hell with that MAP sensor set up and carbon covered everything because of it plus caused rings to stick and oil to blow all over the place. They still ran good and forever though.
Yeah, and the earlier ones had the worlds shittiest injectors too, one big nozzle like a super soaker. No atomization whatsoever.
Unc: Maybe the boys and girls should be reminded to put pieces of fuel hose or those nice plastisol booties by Michigan or Clevitel on the conrod bolts . I have seen many cranks with the telltale mark of 3 or 4 marks from the conrod bolt threads on the journals.
Thank you Sir👍
Between watching this series and David Visard's videos, I'm ready to find a Junkyard engine to build. The LT1 in my 96 Buick Roadmaster sedan has over 170k miles so I know I need to rebuild it. But since I don't have the time, money, or another car to drive. I think getting a complete engine to rebuild would be my best bet. Cause I can't afford any surprises
Thankyou
On bikes wire or spring in the oil is from a seal. On this engine idk.
Got a Honda shadow slave rod seal spring ended up in gear synchro. Not looking forward to taking it apart .lol
I have been in the automotive trade for 49 years, and your instruction is spot on. If I make one suggestion, use a section of broom stick to drive the pistons out, some engines will have a pronounced ridge at the top of the bore, and people that haven't done this before may put too much force into removing them. The wood will absorb some of the beating.
I've got a 4.0 litres jeep in my engine shop that ingested a major amount of water and is literally just chunks of shit . My buddy asked if I could salvage the block and crank .I gave him a quote for a tear down , hot tank , magna flux the block and crank , the deck milled after 6 cyl sleeves then the crank work plus a replacement set of rods and the rebuild kit he decided to just get another one from a junk yard for 400.00 bucks 😂
I blame . . . Wait! . . . What?
@@uncle_moose 👉🏻🐿😎
That crack is very fresh like it just happened when you find the missing piece you should be able to research what happen. As somebody commented leaking injector problem.
I think Uncle T got the motor from my old ZJ. Bad water pump on the way home at 2 am, stopped several times to cool it down. Next day, no startie... bummer...
As I watched you remove the #1 piston, I noticed you just pulled it out of the cylinder without preventing the end of the rod possibly scraping the cylinder wall.
Just a thought Uncle Tony, but you might want to cover the steps to clean and check original pistons for the newbies so they get the scoop for re-using them too. My ring groove cleaner made me do this. Love your channel, always good stuff!
Rebuild on the cheap (budget) was/is a permanent tenet of UTG. Good point
Easy on bouncing your rod bolts against the crank especially if you are not going to polish. I try to never tap on rod bolts that are the stud and nut. If they move in the rod often they don't tourqe up round. I have customers do this often when they pull there motor apart and i often have to resize the rods.
Don't reuse ANY 4.0 or 2.5 Jeep pistons. Replace with aftermarket, even if you're not boring it.
Matye those are safety wires to secure the rod bolts after removing shims to compensate for the babbit bearings wearing. You never know!
Looks like a lightening job on that piston
UTG is the "Bob Ross" of engines ......I can watch either all day long.......well maybe not ALL day.
Tony it would be cool to see you throw a crank and connecting rods out of a 4.2. Turning this into a 4.6 stroker, as well as cam and some port an polish. I feel there is a lot of untapped potential in these engines nobody knows about
This engine is going together bone stock for my daily driver...the one coming out of that Jeep is a different story. That one is going to get the full treatment and will find its way into a lightened 2WD to see what we can get out of it.
It'll be a while before we get to that, but I promise it'll be interesting.
In your opinion what makes these engines so durable and long lasting? In-line six configuration ?
Inline 6 just makes them well balanced and smooth. Longevity comes from the design being under-stressed.
@oneeyedcat3072 sub to him if you can please
As soon as I saw you pull that broken skirt out I said to myself that has to be #6. I think Chrysler undersized the pistons from the factory, and I just did a quick search and it seems that it's common on 99-2002 and that the castings were bad for those years, but why it happens so often on #5 and #6 I'm not so sure.
The girdle is interesting, I personally have an 88 and mine either didn't come with one or was removed.
Those came in 96 along with some added beef to the block for NVH issues ( noise vibration harshness ..) .
They can be retrofitted to earlier blocks .
Kaboom is right on the money. The girdle was a 96+ add on for NVH. As far as #6 popping the skirt, its fairly common when you overheat these blocks, #6 is the hottest running cylinder, due to the path of coolant to it. As far as castings go, thats the head castings. If your head was marked TUPY, it was one of the redesigned heads that fixed the cracked castings due to the coil over plug bosses being too close to the water jacket, Tony's got a distributor ignition engine so he shouldnt have the head issue. Should have the 0621 head on it if my memory serves me correctly.. Tony- your right on the money with the MAP sensor, most likely the vacuum line running from the manifold to the MAP split, and it was getting an atmospheric reading, and the engine went into WOT fueling mode. Had that happen on both the MJ and my 93 XJ once. Usually its the rubber 90 degree fitting that fails. Those rod bearings looked mint though. The old AMC Inline's could take a pounding and keep running. Over-engineering at its finest. Those and the old 300 straight sixes will still be running somehow when the last human is walking the face of the earth lol.
Jeep 4.0's (which also applies to all AMC inline 6's) used letter coded pistons that had generally loose tolerances that varied by a couple ten thousandths of an inch and were selected based on bore diameter to reduce the number of scrapped blocks. That's why OEM Jeep 4.0 have that tell tale noise at idle. A reman motor won't have the noise due to all bore being "equal" and piston matching the diameter. They did the same for rod and main bearings It was common to have different bearing shells top and bottom in both sets of rod and mains to meet tolerance needs. Was a Jeep tech for over 20 years.
The "girdle" was added starting in 1996 to combat NVH (noise vibration and harshness) and did stiffen the bottom end a lot. It's a direct fit all you need are the main bolts, girdle and nuts.
@@carllmack2287 So was I, I started working for AMC in late 85 and transitioned into Dodge in 2006. I worked at several dealerships where I was the only Jeep tech. My easy overflow would go the the Ford techs. I remember crank kits with odd size bearings. I thought that was really strange. I remember the MS1700 scanner, in that blue box. It didn’t just read the codes, it tested sensors as it ran through the program. 🤣
I love this content, Uncle Tony. Thank you