Jackhill442
NAXJA Forum User
- Location
- Atlanta
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?
anony91xj said: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.
Dr. Dyno said: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.
casm said: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.
casm said: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)
Dr. Dyno said: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.
Dr. Dyno said: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.
Dr. Dyno said: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.
jmelby said: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... :bawl:
jmelby said:2001 with 67,000. I should find out later today what the scoop is...