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  #1  
Old March 23rd, 2006, 20:47
Jackhill442 Jackhill442 is offline
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2000 XJ with 122K...Is it prone to head problems?

What is the head problem on the 2000 I keep hearing about, and how likely is it to happen? With good cooling service, can it be avoided?
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  #2  
Old March 24th, 2006, 00:54
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Re: 2000 XJ with 122K...Is it prone to head problems?

Good cooling service will definitely help. These heads are prone to crack between the no.3 and 4 cylinders and overheating the engine makes that more likely.
You've reached 122k miles so you could be one of the lucky ones. Most of the guys who've experienced head cracking problems on their 2000 models had fairly modest mileages (50-80k miles) on their engines.
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  #3  
Old March 24th, 2006, 05:16
anony91xj anony91xj is offline
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Re: 2000 XJ with 122K...Is it prone to head problems?

I've seen and read a lot about head problems on the 99-01 engines on internet forums, and only on internet forums.

That being said, I've never actually seen one in my experiences as a tech. I've also talked to techs at the local Jeep/Chryco/Dodge dealership, and they also said there are no common head problems with Cherokee 4.0 engines. Chrysler has released no head or head gasket-related TSB's that I've seen. I wouldn't worry too much about it honestly.
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Old March 24th, 2006, 05:35
rstarch345 rstarch345 is offline
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Re: 2000 XJ with 122K...Is it prone to head problems?

The head with casting number 0331 is the only one in question.
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  #5  
Old March 24th, 2006, 05:46
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Re: 2000 XJ with 122K...Is it prone to head problems?

Quote:
Originally Posted by anony91xj
I've also talked to techs at the local Jeep/Chryco/Dodge dealership, and they also said there are no common head problems with Cherokee 4.0 engines. Chrysler has released no head or head gasket-related TSB's that I've seen.
Either the problem with the 0331 heads hasn't been reported to them or they (and DC) have got their heads in the sand. I've heard of so many 0331 heads cracking between the no.3 and no.4 cylinders that I've lost count. I'm only surprised that owners of Jeeps stuck down by this problem haven't banded together to take a class action suit against DC.
Even here in the Gulf, the 0331 heads are considered to be junk because of the same cracking problems. That said, it seems to be only year 2000 models that are affected while 2001-2006 versions seem to be problem-free, so it's possible that just one large bad batch of castings was produced some time in 2000. Unfortunately some of them also made their way outside the US.
I'd be interested to find out the build dates of the Jeeps that have suffered these problems.
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  #6  
Old March 24th, 2006, 07:08
2001XJeep 2001XJeep is offline
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Re: 2000 XJ with 122K...Is it prone to head problems?

Well that is somewhat good news, at least for me and my 2001 (no problems to report at 68k). I wonder if this is common to all 2000 4.0's (including TJ's & WJ's)? If so then hopefully my brother-in-laws WJ will be spared.
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  #7  
Old March 24th, 2006, 10:52
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Re: 2000 XJ with 122K...Is it prone to head problems?

Quote:
Originally Posted by Dr. Dyno
Even here in the Gulf, the 0331 heads are considered to be junk because of the same cracking problems. That said, it seems to be only year 2000 models that are affected while 2001-2006 versions seem to be problem-free, so it's possible that just one large bad batch of castings was produced some time in 2000.
I've got a 2000; no idea if it's the 0331 head or not (and if someone can let me know the place to look on the block I'd appreciate it) but it just turned 100,000 miles this past weekend and I'm not seeing any coolant loss, coolant/oil mixing, or other early signs of impending head or head gasket failure. I've owned it since about 72,000 miles and the coolant was changed both immediately after I got it (looked factory-original judging from the colour and sludge) as well as about two months ago as part of normal maintenance.

What I am wondering, though, is if this might be related to the TSB for the #3 injector heat soak issue. Since the cracks seem to happen between the #3 and #4 cylinders, there's enough suppositional evidence to suggest that they may not be completely unrelated.
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Old March 25th, 2006, 02:24
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Re: 2000 XJ with 122K...Is it prone to head problems?

Quote:
Originally Posted by casm
What I am wondering, though, is if this might be related to the TSB for the #3 injector heat soak issue. Since the cracks seem to happen between the #3 and #4 cylinders, there's enough suppositional evidence to suggest that they may not be completely unrelated.
No, they're completely unrelated. The head cracking issue seems to be the result of several bad castings and I can only speculate that the cast iron used in one large batch must have been of poor quality.
The area between the no.3 and 4 exhaust ports is the hottest part of the head and is subjected to the largest temperature fluctuations, making that the area most prone to crack.
The first sign of a problem is unexplained loss of coolant. If there are no external coolant leaks, remove the oil filler cap and look between the valve springs of the no.3 and 4 cylinders. A crack is usually too small to be seen with the naked eye but you WILL see crusts of coolant in that area and that's a telltale sign.
Left neglected, enough coolant can accumulate in the crankcase to contaminate the oil and result in accelerated main/rod/cam bearing wear, manifesting as low oil pressure.
If the crack is between an intake port and the water jacket, the engine might run like it's on 5 cylinders. If it's between an exhaust port and the water jacket, you'll have steam coming from the exhaust but the engine will run fine.
If the crack is only between the water jacket and an oil gallery, you'll only have the mystery loss of coolant with the engine otherwise running well.
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  #9  
Old March 25th, 2006, 13:16
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Re: 2000 XJ with 122K...Is it prone to head problems?

Quote:
Originally Posted by casm
I've got a 2000; no idea if it's the 0331 head or not (and if someone can let me know the place to look on the block I'd appreciate it)
If you look right on the top of the head, about mid-way down on the drivers side, you should find the stamp number. You might need a flashlight to see it, depending on how dirty your engine is. It should be located right where the top of the head and the bottom of the valve cover and everything else meet up. If it wasn't pouring right now and I wasn't sick, I'd go take a pic for you.

On a side note, Everything i've read suggests that the 99's also had this problem. However, I have a 9/99 build date on my XJ and have the 0630 head on the orig. motor. So perhaps any 99's that have the 0331 are extremely late 99 models, right as they were switching over to the 2000 model year?
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  #10  
Old April 4th, 2006, 12:17
jmelby jmelby is offline
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Re: 2000 XJ with 122K...Is it prone to head problems?

Quote:
Originally Posted by Dr. Dyno
No, they're completely unrelated. The head cracking issue seems to be the result of several bad castings and I can only speculate that the cast iron used in one large batch must have been of poor quality.
To continue with this subject and my currently ailing ride...

I didn't see what the number on the head was on mine. I looked rather quickly, but didn't find it...

Quote:
Originally Posted by Dr. Dyno
The area between the no.3 and 4 exhaust ports is the hottest part of the head and is subjected to the largest temperature fluctuations, making that the area most prone to crack. The first sign of a problem is unexplained loss of coolant. If there are no external coolant leaks, remove the oil filler cap and look between the valve springs of the no.3 and 4 cylinders. A crack is usually too small to be seen with the naked eye but you WILL see crusts of coolant in that area and that's a telltale sign.
The inside of the oil cap was horribly milky - it had about 1/2" of milky buildup on it. Just inside the oil cap had some milky crap on the springs as well. There is also a drop of antifreeze on top of a bolt head in there. When I started it and warmed it up and looked inside the oil cap, it looks as though small drops are forming closer to the #4 side on the inside. I have pictures that sort of show it, but haven't seen how to add them in here quite yet.



Quote:
Originally Posted by Dr. Dyno
If the crack is between an intake port and the water jacket, the engine might run like it's on 5 cylinders. If it's between an exhaust port and the water jacket, you'll have steam coming from the exhaust but the engine will run fine.
If the crack is only between the water jacket and an oil gallery, you'll only have the mystery loss of coolant with the engine otherwise running well.
It runs fine, and the exhaust might be a little steamy, and it seems a little steamy inside the oil cap while it's running and warmed up. Is a little steam normal or is it from the antifreeze in it? I originally thought it was more of a mystery loss, but maybe it is coming out the exhaust...

Any comments or suggestions? It's in the shop waiting for a call to do a head gasket job. Wonder if they'll find a cracked head as well...
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  #11  
Old April 5th, 2006, 05:08
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Re: 2000 XJ with 122K...Is it prone to head problems?

Quote:
Originally Posted by jmelby
The inside of the oil cap was horribly milky - it had about 1/2" of milky buildup on it. Just inside the oil cap had some milky crap on the springs as well. There is also a drop of antifreeze on top of a bolt head in there. When I started it and warmed it up and looked inside the oil cap, it looks as though small drops are forming closer to the #4 side on the inside. I have pictures that sort of show it, but haven't seen how to add them in here quite yet.

It runs fine, and the exhaust might be a little steamy, and it seems a little steamy inside the oil cap while it's running and warmed up. Is a little steam normal or is it from the antifreeze in it? I originally thought it was more of a mystery loss, but maybe it is coming out the exhaust...

Any comments or suggestions? It's in the shop waiting for a call to do a head gasket job. Wonder if they'll find a cracked head as well...
It's an odds-on bet that your head has cracked in the commonest place; between the no.3 and 4 cylinders. The crack may only be on the top between the crankcase and the water jacket but the head is most likely still to be junk. A little steam from the exhaust on a cold damp day when the engine's cold is normal, but steam appearing when the engine's hot definitely isn't.
What year is your XJ and how many miles on the engine? The 2000 model seems to be the worst affected by the head cracking issue.
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  #12  
Old April 5th, 2006, 05:24
jmelby jmelby is offline
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Re: 2000 XJ with 122K...Is it prone to head problems?

2001 with 67,000. I should find out later today what the scoop is...
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  #13  
Old April 5th, 2006, 08:19
75SV1 75SV1 is offline
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Re: 2000 XJ with 122K...Is it prone to head problems?

I've seen two and another one was worked on by the same tech, my neighbor. I sold an '03 head to repair one. All three were around 80K and looked well maintianed. The main problem is people run them for several K miles. This damaged the bearings. Hopefully you caught it in time. Well, at least I got an '00 motor minus the head for $40.
Tom
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  #14  
Old April 7th, 2006, 11:32
jmelby jmelby is offline
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Re: 2000 XJ with 122K...Is it prone to head problems?

EMERGENCY!!! Head is cracked - casting number 0331 on a 2001... Anyway, do I have to get the same casting number for the head or are there substitutes that will work fine? Anybody have a spare head?

I can get a motor with 44k on it for around $700, plus a little extra for a one year parts and labor warranty if I want...

Last edited by jmelby; April 7th, 2006 at 11:44.
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  #15  
Old April 7th, 2006, 11:51
75SV1 75SV1 is offline
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Re: 2000 XJ with 122K...Is it prone to head problems?

Any of the other heads will fit. You might try :
http://www.car-part.com/
Look for the * in the results. That will be the lowest prices. You can even put on an earlier head. I don't know the legality of that though. The later heads will be OK. The 91-95 don't have the dowel pin locator holes, but will fit.
Tom
I would guess a head will cost about $200-$300. You might consider the motor deal. If you've run that engine any amount of time with coolant in the engine, you might have damaged the bearings.
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