kermit-xj

i have a 2000 model xj with the legendary 4.0 hi output 6 cylinder. and the question is does the valve cover leak on this engine? is it a common problem it has about 140k miles.

elnino

legenday 4.0....you mean better than the 2.5....

haha...honestly i dont think is a common problem...just replace it...mine has 110k and is kind of leaking..

kermit-xj

lol. got love it.

muddeprived

Mine leaks too. I had 6 drops of oil on my head from working under there today.

Are there high output 4.0's on the newer cherokees? I didn't know that...

XJ90

i believe that all 4.0's after 91 are high output. just they didn't badge it as high output after 97.

okcjeeper

yeah replace the gasket with the nice expensive felpro one not the cork but the nice rubber one..Costs more but IMHO much better...

Bouncy

Either go with the rubber gasket or get a tube of RTV and make your own.

I have seen inch thick RTV put in there in place of gasket and it did hold.

Skip cork its a pita to get cleaned out when it goes bad...and it will.

UNCC_99XJ

3 most common oil leaks on a 4.0:

• Valve Cover Gasket
• Oil Filter Adaptor O-Rings
• Rear Main Engine Seal

So yes, it's quite common, and quite easy to fix. As for which gasket, they're expensive no matter how you look at it. I got a nice cork one a couple of years ago and haven't had a bit of trouble since.

muddeprived

Hmm i didn't know you could use RTV on that.

nick_n_ii

All AMC inline 6's for the beginning through '06 have two common problems, leaky rear mains and leaky valve covers. Some go 250K no prob other only 20K...