So I've been kicking around the idea of buying this 02 Grand with the 4.0, about 124k miles on it. I crawled under it today and what would you guess is leaking? The Rear Main Seal!! I just find it hard to believe it is 9 years newer than my 93 XJ yet has the same old typical 4.0 leak. Not a very useful thread I know, but I had to share this with some people who would know what I'm talking about. While I'm at it....Any thing to look out for with the 02 Grand Cherokee Laredo other than typical stuff to look out for when buying a vehicle?

 

I think that year still has the bad head on it

 

Bad head.....what mileage does that usually go out at? I'm really trying to decide if I should buy it....Can't sit on money too long cuz **** happens then it's gone...Every one knows that. It's pretty clean and in good shape, Arizona lifetime so no rust...Clean Carfax...Priced a little over blue book but not a huge deal...Just figured since it has the 4.0 I should be some what familiar with it. Gonna replace my XJ due to rust and a lot of other issues.

 

it may not have it, and if it does have the 0331 it may not be defective, or it may have a 0331 tupy which had the stronger metal in it

just search google and be sure to maintain the cooling system as with any engine

 

yeah I'm searching and finding a slough of info, but nothing really conclusive except to look through the oil fill cap for the TUPY stamp. But my father in law who works at a dodge dealership says it should have the 0334 cylinder head, build date of 7-5-1, so I'm pretty confused.

 

Sure it's the RMS?

I'd be looking up above first. A leak at the back of the valve cover could produce the same symptoms. Don't jump on the RMS/oil pan gasket bandwagon just yet.

Almost any oil leak on your 4.0 is gonna drip from the RMS area for 2 simple reasons. First off, the engine sits nose-up and oil will run back to that area. Secondly, the RMS area is also the lowest point on the engine. Simple physics and the old plumber's adage apply here. "$hit flows downhill".

Valve cover gasket, oil pressure sending unit, oil filter adapter seals and distributor gasket have to be eliminated as possibilities first.
Revised 3-23-2012

 

lol, rms band wagon, you very well could be right.

 

Guess I just gotta look under the oil fill cap. 0334 could be the part number but the casting number could differ. Can't anything just be straight forward

 

This oughtta help you out if you're serious about buying one:
http://www.jeepforum.com/forum/f310/...guide-1271979/

 

I am looking at this one very seriously. This is a great link. Thank you.

 

damn... it says the trannys that come with the 4.0 often fail. Too bad they didn't keep the aw4 huh....

 

Now I understand not all the 0331 heads crack...but are the ones that are cracking doing so with out being overheated?

 

there is polls out with mileage being a factor but ive not seen anything about overheats although have read if the 0331does overheat bad a couple times its pretty much dunzo

 

well I appreciate the heads up... Good info....even though it's giving me more "buyers anxiety". Lol.

 

Just FYI, the innard from the 42RE trannies that come with the 4.0 can be replaced with the stronger guts from the 44Rsomething or other.