1999 Jeep Grand Cherokee

[Donald]

Originally Posted By: jeepman3071
Originally Posted By: Chris142
Not every head cracks and not every piston breaks. If its got almost 200k on it chances are that it will be ok.my 02 has the updated 0331-tupy head. I'm at 144k and my pistons are ok...so far.


+1


Yes, thats true. But two people on this forum (myself and zrxkawboy) had the issue with cracked piston skirts, and the shop that replaced my engine had done a few for the same reason. So I would say its not uncommon.

 

[Nick1994]

My grandpa has a 1996 Cherokee 4.0, 131k miles runs absolutely perfect, no issues. My brother has a 1991 Cherokee 4.0, 212k miles runs fantastic

 

[rslifkin]

Originally Posted By: fdcg27
Is this one of the model years known for disintegrating piston skirts?


Yeah, it's within the years that do that, but it's a pretty rare problem overall. The issue started when they switched to aluminum pistons in 96.

The cylinder head cracking is more common, but isn't guaranteed to happen. If it starts losing coolant and you can't find where it's going, it's probably in the oil. Replacing a head can be DIY-ed for about $1200 (with a head that won't crack in the future) and is doable in a weekend.

As far as transmissions go, make sure the fluid is kept fresh, the bands are adjusted properly and add an extra trans cooler. If you do that, they'll generally hold up fairly well (and if it goes, they can be rebuilt to be pretty much bulletproof). It's basically just an old 904 Torqueflite with a lockup TC, an electronic governor and an OD unit bolted to the back. I've got the 727 based big brother of that trans in my Jeep and it's still going at 158k miles (some fail earlier, some will break the 200k mark). And mine hasn't lived an easy life (although I take good care of it and I added a shift kit when I cranked up the power).

ECU failures are actually pretty rare, it's not something I'd be worried about.

If it's got the fulltime 4wd transfer case (quadra-trac or quadra-drive systems), use only the special dealer fluid. The part time system just uses ATF in the t-case.

If the front brakes start having issues, upgrade it to the later design Akebono front calipers if it hasn't been done already. They're much less prone to issues.

The only other common issue is the relays for the e-fan failing. But again, that's hit or miss. I've seen WJs break 110k without a relay failing and others go through several relays in that mileage.