Cylinder 6 piston failed

BrunoPizz97 said:
currently swapping in an 01' cherokee 4.0 will post pics.
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Just a word of caution in case you didn't already know. The original 0331 cylinder head on the 2000-2001 Cherokee 4.0L's were known to have the same weak spot the Wranglers shared for a year or two around that same time period. The newer 0331 TUPY head (TUPY was stamped between cylinders 3 and 4) is known to be the improved head. Your 4.0L donor may already have a TUPY head if it had issues at some point in it's life. If not, it doesn't guarantee you will have an issue, but the redesign does show there was a flaw deemed important enough to fix.

P.S. See this thread that shows how to check
https://wranglertjforum.com/threads/how-to-identify-0331-or-tupy-head.8112/
 
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Vidar said:
Piston 5 went on me a few weeks ago. I’m going the rebuild route. $700 for the machine work on the block and head, and another $650 for the rebuild kit. Mine had just shy of 210k on it.

View attachment 143056
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I lost number 5 on mine too!
I could have rebuilt it if I haden't drove 10 miles to where I could park it safely...
Damn the 4.0L is one tough little booger!
Skirt failure is common though... Just sayin...

IMG_0559.JPG
 
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mots said:
Just a word of caution in case you didn't already know. The original 0331 cylinder head on the 2000-2001 Cherokee 4.0L's were known to have the same weak spot the Wranglers shared for a year or two around that same time period. The newer 0331 TUPY head (TUPY was stamped between cylinders 3 and 4) is known to be the improved head. Your 4.0L donor may already have a TUPY head if it had issues at some point in it's life. If not, it doesn't guarantee you will have an issue, but the redesign does show there was a flaw deemed important enough to fix.

P.S. See this thread that shows how to check
https://wranglertjforum.com/threads/how-to-identify-0331-or-tupy-head.8112/
Click to expand...
Or, just look down the oil cap... Whoop! there it is!

TUPY.jpg
 
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mots said:
Nice, that one is perfect, even better than the cap picture I linked. Glad you got a TUPY! Let’s hope the OP has a TUPY too! (Not be be confused with toupee, LOL).
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What did you mean by that.... Ha ha ha!
And no, that hat is not to hide the dreadlocks...

FatherChristmasII.jpg
 
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mots said:
Just a word of caution in case you didn't already know. The original 0331 cylinder head on the 2000-2001 Cherokee 4.0L's were known to have the same weak spot the Wranglers shared for a year or two around that same time period. The newer 0331 TUPY head (TUPY was stamped between cylinders 3 and 4) is known to be the improved head. Your 4.0L donor may already have a TUPY head if it had issues at some point in it's life. If not, it doesn't guarantee you will have an issue, but the redesign does show there was a flaw deemed important enough to fix.

P.S. See this thread that shows how to check
https://wranglertjforum.com/threads/how-to-identify-0331-or-tupy-head.8112/
Click to expand...
Not sure if it’s TUPY or not but I do know that the motor has been well maintained. I’ll check on my old head and see if it was TUPY, I didn’t even know this was a common problem.
 
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Jeepn_Texas said:
I lost number 5 on mine too!
I could have rebuilt it if I haden't drove 10 miles to where I could park it safely...
Damn the 4.0L is one tough little booger!
Skirt failure is common though... Just sayin...

View attachment 143167
Click to expand...
I was 160 miles away from home so I kinda just said screw it because it was already knocking if I made it home I made it home if not then oh well
 
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BrunoPizz97 said:
Not sure if it’s TUPY or not but I do know that the motor has been well maintained. I’ll check on my old head and see if it was TUPY, I didn’t even know this was a common problem.
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Cool, good luck with the repairs. I didn't know about the 0331 head issue either until I got bit by the TJ bug, and of course the venerable 4.0L that comes with it. I am also fond of the XJ's and was disappointed to learn this of the 2000-2001 years when I was eyeing up a 2001 near me that was in great shape in and out. Unfortunately being all original, it also has problem heads. I figured no way I am paying top dollar for an XJ and then getting into this situation. I've decided to look for the more recommended 90's models instead, if I decide to look for an XJ again.
 
BrunoPizz97 said:
Those wheels gotta go
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I know, I like how they look but... weigh a ton and to be honest, I like steel wheels.
You can bend them back, paint them and scrape the crap right out of them!
Those are a booger, they are out of balance one has like 4 lbs. of weights on it...
If they did that and then ran them, the tire is probably way out of balance again!
Going to put them up for trade to see if I can just get some steels...
 
Jeepn_Texas said:
I know, I like how they look but... weigh a ton and to be honest, I like steel wheels.
You can bend them back, paint them and scrape the crap right out of them!
Those are a booger, they are out of balance one has like 4 lbs. of weights on it...
If they did that and then ran them, the tire is probably way out of balance again!
Going to put them up for trade to see if I can just get some steels...
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I have Steelies and there nice idt I would run any other whee besides a beadlock
 
The Xj block is slightly different than the tj in the bracket machining, the alternator doesn’t mount the same , not sure if you were aware
 
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