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 ...?

An easy trick to not lose parts or fasteners is to minimize the time between tear down and reassembly

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.

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.

I usually number stamp my rod caps and main caps. That's was what my grandpa use to do.

There are some interviews here on KZfaq 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.

Making a video or group of videos that give a semi detailed instruction to engine tear down, rebuild and reassembly is a daunting task.

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.

Love the slow pace of these videos. For a guy who knows FA about stuff like this, it's fascinating.

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!

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

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.

That Craftsman ratchet. The best design ever.

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!

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.

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!!!

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

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.

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.

Classic case of muffler belt too loose causing the timing regulator to over stimulate the carbinator thus the #6 piston failure.

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 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 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.

When you said "Just use an airgun !" I laughed. My OCD was saying the exact same thing ! Lol

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.

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 .

Valve job, new rings, bearing, new cam with lifters, gaskets, soft pugs, etc ! $500 AND 100,000 MILES! GOOD to go!

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.

What about numbering the rod caps and rods to make sure you get them back on the way they came apart

Watching a bunch of your videos and its making me really excited to start tearing down and rebuilding my 327.

the wire you keep finding could be the spring under the timing cover that keeps the camshaft back

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.

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 can't believe that "chunk" came off and dropped into the pan without damaging anything else in the process. 😮

great content, have a 318 I'll be doing my 1st complete rebuild this summer. This series of yours is perfect. Thanks!

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

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.

YOU TAKE YOUR TIME ! All the time you need !

You know he’s an old school mechanic when he likes using hand tools

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!)

I like the way you work and operate:) I have a 1997 Cherokee I've had 20 years. Good vehicle:)

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

Reminds me as a kid watching chuck on horsepower tv, he always used a speedwrench every chance he got lol.

YES!!! Early to a video release!! Thank you for these videos.

I love the tap on the rod bolt nuts technique to separate the rod cap from the rod thank you

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 !.

YES!!! The Old School "Speed handle" 👍👍

Very similar of how I work.. again great conformation that I have been on track with my projects…

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.

Tony's speed wrench......classic ! ...and yes I do own one .

Told you number 6 had something wrong with it! Go back to the first video and look at the number 6 exhaust valve and the color of the plug, totally different from the other five! It was burning way leaner for obvious reasons!

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.

You're doing God's work, Uncle Tony. Truly, thank you.

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.

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.

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.

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!

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?

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.

Same. I like to "feel" what the bolt or nut does as I remove or tighten.

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 😂

Watching you work on that straight 6 make me want to tear down my slant 6.

Great video, nice job.

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.

Thank you Sir👍

is it possible the bits of wire came from the oil pick up tube strainer thing? thats all i can think of

I found the “”wire “in my pan too ! Looked like a round needle

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.

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 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...

On bikes wire or spring in the oil is from a seal. On this engine idk.

What are the correct installed degrees between the top (firing) compression ring, second compression and the third (oil) ring in reference to the piston boss?

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

Magical video. 😊

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.

Good idea to use sump pan for all the pieces I do the same

Peace from the fringes of the jersey turnpike.

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.

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.

The item you called a girdle, it seems to be pretty heavy gauge metal, but looks a bit like a minimalist windage tray, is it actually there to stabilize the main caps? It’s a low stress engine, I’m surprised it would be needed, but they wouldn’t go to the expense of adding it if it wasn’t.

I learn alot from you.

My 79 F150 302 has both piston and connecting rods stamped with cylinder numbers from the factory in 79. Are all pistons stock and the difference in the cylinder is taken up by the rings (ie) 30 over ect? My truck is bore is 4” and 3” stroke. Just asking.

Does the piston swap work well or do anything for the inline 6 engines?

Was the broken portion of the piston on the left side or right side of the bore?

I wonder if those head bolts being stretched wasn't made worse by only one trip over them with the torque wrench? Or if they weren't loose from the factory? I did some work on a couple N14s a few years ago, it took 6-8 times over the torque pattern til they all stayed tight.

I love this content, Uncle Tony. Thank you

These videos are great. Like watching Bob Ross on engines.

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.

Thankyou

When the check engine light comes on. Sometimes it really really means check the engine. Especially when the check engine light stops working.

Where did the piston parts go? In pan?

Why why why did the piston break Uncle Tony? I have this very same problem, had to change my oil pump and I found 2 pieces of skirt in the bottom of the oil pan. After careful consideration I looked at my budget. So I put it back together, so far 10,000 miles later just a little slap sound still goin 1/21/23

I think that jeep 4.0L was built on a Thursday before a long weekend

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.

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.

Even though my engine re-builds were done with all new parts, could you put a new cam in with old lifters ? Thanks in Advance. Tight lines Captain Keith

Somebody's definitely been in that bottom in because that is not a factory gasket that's a Fel-Pro gasket aftermarket

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.

What would you say is safe piston to wall clearence I'm looking on the internet all over it's a low like 3500 maybe 4k rpm motor I just can't find anything on safe piston to wall clearence trying to figure out if I need machine work on this motor or not