I recently purchased a 96 Cherokee with the HO 4.0 and 202k on the odometer. Ran rough and after a compression check cylinder 3 and 5 were down to 50psi. (code p0300, p0303, and P0305 also showed) The previous owner said she had ran it hot.

I had the chance to pull the head this weekend and wanted to share the sad story with pictures. (After I figure out how)

First up may be the culprit. Two leaking freeze plugs behind the exhaust manifiold.

Next is clogged water passages from copper snake oils

Next is Blown head gasket from Cylinder 3 to 5

Last the cracked #4 Cylinder wall

The leeking freeze plugs behind the exhaust manifold I believe started the downhill plunge because they possibly never "dripped" water

 

If the cylinder wall itself wasn't cracked, I would say check the block for warping, get a new head and gasket, flush it all out really good, fix the freeze plugs, check the water pump for play, and make sure the radiator isn't clogged at all. But the cracked cyliner wall pretty much kills the idea of a repair. Unless its possible to have a shop fix the crack. How deep is it? You might be better off just getting a jy or rebuilt engine. I hate it when people say "Oh, jeeps suck b/c I had one, and had nothing but problems..." Its either the previous owners fault, your fault, or just bad luck, usually just bad luck. People think they don't have to take care of the 4.0 b/c its an insanely great engine, the best one i've ever had, but that doesn't mean you can run it without oil or coolant, its still an engine, and the best one ever made! New jeeps have the V6 that chrysler borrowed from the dodge caravans... A minivan motor in a Jeep? Whats this world come to? My aunt has a KJ with the V6, and the thing sounds like a sewing machine, I hate it. And I hate the KJ (Liberty) too, they though it could replace the XJ, nothing will ever come close, especially the new Cherokee. I like it wayyy more than the liberty, and I'm happy to see the Cherokee name back, and I'm happy the XJ's so called replacement (liberty) is now dead. haha
4LHO FOREVER!!!!!!!

 

If the cylinder wall itself wasn't cracked, I would say check the block for warping, get a new head and gasket, flush it all out really good, fix the freeze plugs, check the water pump for play, and make sure the radiator isn't clogged at all. But the cracked cyliner wall pretty much kills the idea of a repair. Unless its possible to have a shop fix the crack. How deep is it? You might be better off just getting a jy or rebuilt engine. I hate it when people say "Oh, jeeps suck b/c I had one, and had nothing but problems..." Its either the previous owners fault, your fault, or just bad luck, usually just bad luck. People think they don't have to take care of the 4.0 b/c its an insanely great engine, the best one i've ever had, but that doesn't mean you can run it without oil or coolant, its still an engine, and the best one ever made! New jeeps have the V6 that chrysler borrowed from the dodge caravans... A minivan motor in a Jeep? Whats this world come to? My aunt has a KJ with the V6, and the thing sounds like a sewing machine, I hate it. And I hate the KJ (Liberty) too, they though it could replace the XJ, nothing will ever come close, especially the new Cherokee. I like it wayyy more than the liberty, and I'm happy to see the Cherokee name back, and I'm happy the XJ's so called replacement (liberty) is now dead. haha
4LHO FOREVER!!!!!!!

 

I was able to post pics in an album... the crack is about 2.5 inches long if it is indeed a crack.

 

Sounds like it's done.

Completely replace the whole engine (long block) or you will be chasing expensive problems forever.

 

Last time I saw a crack like that was on a 403 Pontiac, a long time ago. The head still looks good though(maybe?), that'll save you about 2 to 400 dollars if it is good still.

 

I'd say it's shot with that crack, I'm sad to say that because these great engines aren't made anymore, and if people don't take care of them, we won't have any left.

 

Considering I see one every 10 minutes in traffic, I don't think you have to worry

 

I just love them so much! Xj's are very common on Long Island in New York, but those ugly jk's are starting to become more common, but the xj's are still here, the jk's aren't replacing xj's at all! But jeeps are becoming more popular in general, I'm starting to see a lot more modified xj's though. But Long Island is flat, so the beach is all we've got.