Broken piston skirt, now what

grr

grr

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Well started tracking down a knocking noise the other day in my 00 4.0. 150k miles on it and thought it might be the timing chain. Took cover off and chain had lots of slack so I thought I found the noise. But I also knew from reading the forums it could be a piston slap so since I also had a slow leak in the rear main I decided to pull the pan and fix it while I had it tore down.Sure enough there were broken pieces of piston laying in it. Now what? Just fix the 1 piston(#5) or more? Some may suggest stroking it. It's got a 4" lift with 35's. it's my dd and I Offroad it 8-10 times a year. Not going any bigger and I have been very happy with the way it runs stock.
 
Well, I know for a fact you can get fully remanufactured (basically brand new) 4.0 engines for around $1500-$2000 (I had to buy one once).

That being said, I figure you've got a few options:

1) Fix only the piston in question (though you'll want to remove the whole engine and inspect all of the pistons just to be sure)
2) Rebuild the entire engine yourself
3) Buy a remanufactured engine
4) Buy a stroker engine or build your own

It all depends on what your budget is. Personally, I would choose #3 being as though I wouldn't dump money into a 4.0 stroker. At that point I'd just save more money and throw in a V8!
 
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I *just* had my 4.0 totally rebuilt from the bottom up, and it cost me 2k with a brand new mopar crank put in it also (old one was pretty far out of spec).
I can say, it is reaaally nice as a new engine.

I think if you have the resources and time to either do a rebuid, or have one done, it will be more worthwhile. I mean, you'll be in there anyway... ;)
 
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Thanks for the replies guys. I was afraid these were my options. As I said it's my dd and the wife and I have taken it on a few Offroad trips. We went to NM for week (8 hr trip) in it and we have gone on a Jeep Jamboree about 5hrs away. We had a lot of fun and plan on more of those. So I don't want to drive it til it blows, I want a dependable ride. I drove it maybe 5 or 6 miles after the noise started and parked it. It hasn't moved since. Maybe I should just tear into it myself. I've done almost all of the other work on this 17 yr old heep. Everything from new axles, control arms, armor, brakes, steering, winch, lights, to starting on the timing chain and rear main seal, but I have never tore inside the engine. But I can read and follow instructions. Just fearful of the time it will take.
 
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grr said:
Thanks for the replies guys. I was afraid these were my options. As I said it's my dd and the wife and I have taken it on a few Offroad trips. We went to NM for week (8 hr trip) in it and we have gone on a Jeep Jamboree about 5hrs away. We had a lot of fun and plan on more of those. So I don't want to drive it til it blows, I want a dependable ride. I drove it maybe 5 or 6 miles after the noise started and parked it. It hasn't moved since. Maybe I should just tear into it myself. I've done almost all of the other work on this 17 yr old heep. Everything from new axles, control arms, armor, brakes, steering, winch, lights, to starting on the timing chain and rear main seal, but I have never tore inside the engine. But I can read and follow instructions. Just fearful of the time it will take.
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That's the thing... the time it takes. Honestly, if it's your DD, I'd just try and take the hit and have a shop rebuild it (Or, get the crate engine - there are some pretty nice ones out there). That way, not only will it get done more quickly, but they will be responsible if anything goes wrong in the end. Especially quickly if you get the crate engine, since it's a plop and swap ;)

It is a lot of cash - but if you can swing it, it would be totally worthwhile for the peace of mind and longevity. I know I feel *very* confident in my engine now!
 
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Rebuilding engines isn't a trivial exercise. Yes, you can do it yourself in your garage and have a good outcome. You can save some cash if you do it yourself. But, it takes a lot more specialized tools to do it correctly than one would suppose. You need to run around to find someone to do the machine work on your head, block, crank and etc. Not all machine shops are the same in regards to tooling and experience. One example would be getting the block prepped. Does the machine shop you selected have the appropriate deck plate to hone the cylinders? Can you select and fit the proper crank bearings? Lots of minor details go into a rebuilt engine that can add up to something wonderful or something ugly and useless.

My vote would be snag a crate engine and plug it in. That's going to be enough of pain as it is.
 
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Agee about the rebuild it yourself. Unless you have the tools, the space and especially the good machine shop contact it could be a very bad experience. I have been researching Golan and Titan engines. Also found a reputable local shop that will rebuild mine compete for $2500. Seems like I could buy a crate for cheaper but like the idea of rebuilding mine locally. He gives a 1 year warranty and is literally about a mile from my house. If I have a problem I could stop by his place on the way to work.
 
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Decided to pull my engine and have it rebuilt. Never pulled one before, should be fun. Took pics. Got almost everything disconnected and labeled. I have to get my a/c discharged and then unbolt my manual tranny and it should be ready. Still researching easiest way to do both.
 
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Got the motor ready to pull, it will be out tomorrow. Just wondering what you guys thought I should fix/upgrade while I have it out? Again , 150k on it. Clutch was replaced at about 90k, so does it need any1hing? What about fuel injectors? They are original. Should I replace them, or maybe the o rings? What else should I look at?
 
I would replace every single seal and o-ring you can just as preventive maintenance. It's so much easier when the engine is out. The fuel injectors should be fine though.

As for the clutch, I personally would throw a new one in just because. Well, if it wasn't too expensive I mean
 
Let's see. You found parts of piston in the pan? So how much got into the oil circulation system? This is a total disassembly and spec out of all bearings! That is if you really want a dependable DD.

Pull the head etc and replace the piston, ring etc and hope that nothing else was damaged. That's what I did when I was drag racing on the street--50 or so years ago. Know what? I ruined a lot of engine blocks that way.

When you have crap in the pan the bearings have been affected. I would suggest a crate engine as the easiest way out of this mess. Sorry but good luck. Please follow up.
 
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Stinger said:
Let's see. You found parts of piston in the pan? So how much got into the oil circulation system? This is a total disassembly and spec out of all bearings! That is if you really want a dependable DD.

Pull the head etc and replace the piston, ring etc and hope that nothing else was damaged. That's what I did when I was drag racing on the street--50 or so years ago. Know what? I ruined a lot of engine blocks that way.

When you have crap in the pan the bearings have been affected. I would suggest a crate engine as the easiest way out of this mess. Sorry but good luck. Please follow up.
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Stinger: Yea pieces of piston laying in the pan. Drove it maybe 5 miles after the "slap" noise started. I too worry about other damage though. Figure with 150k miles if it must be tore down for inspection it's a good time for a rebuild. Got the motor pulled out and stripped down today(well, over the last 3 days). Taking it to a local shop this week. Will update progress of rebuild. I am on my 2nd clutch, not sure how many miles on it. It looks ok but wondering if I should change it too while I have the engine out?
 
grr said:
Stinger: Yea pieces of piston laying in the pan. Drove it maybe 5 miles after the "slap" noise started. I too worry about other damage though. Figure with 150k miles if it must be tore down for inspection it's a good time for a rebuild. Got the motor pulled out and stripped down today(well, over the last 3 days). Taking it to a local shop this week. Will update progress of rebuild. I am on my 2nd clutch, not sure how many miles on it. It looks ok but wondering if I should change it too while I have the engine out?
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Sorry to say but think about it. How many rpm were those internal pieces facing while you Only went 5 miles?

I am in the process of rebuilding a 1970 Jeep Gladiator pick up. If it even smells like it may be bad it gets replaced-—-don't want to worry about it or tear the SOB down to fix it later.
 
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Just to follow up on this....had my motor completely rebuilt. Bored 30 over, new silverlite pistons, mild comp cam, melling oil pump, timing set, balanced etc. While I was at it replaced the clutch, crank pos sensor, coil pack and a few other small things. Cost of rebuild was way more than a reman but at least I knew everything would bolt back up. Runs great, very smooth and no cels. Anyone who says it's ok to drive it while making that knocking or tapping noise needs to look at that pic.

IMG_0024.JPG
 
grr said:
Just to follow up on this....had my motor completely rebuilt. Bored 30 over, new silverlite pistons, mild comp cam, melling oil pump, timing set, balanced etc. While I was at it replaced the clutch, crank pos sensor, coil pack and a few other small things. Cost of rebuild was way more than a reman but at least I knew everything would bolt back up. Runs great, very smooth and no cels. Anyone who says it's ok to drive it while making that knocking or tapping noise needs to look at that pic.
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Excellent news. Congrats on another 150k engine.
 
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