TJ Valve Cover Options?

[Rubicon]

I am looking/needing to replace the valve cover on my '04 TJ Rubicon (4.0) with about 104,000 miles. I've sprung a leak from the valve cover & will be pulling the old one off over the weekend & at least replacing the gasket and torquing the bolts back down properly.

I'm thinking of "upgrading" to an aluminum cover, as I've "heard" that they can dissipate heat a bit more efficiently than steel, and also that they can help "quiet" some of the valve train noises....

Does anyone have any experience with this? Not sure it's worth the $$$ to replace the cover with aluminum, or keep the stock stamped steel one. Not sure if the factory one is "tweaked" at all (but there is a definite leak & from what I can see the gasket is shot), since I haven't had a chance to pull it off.

I've searched the forum a few different ways & haven't been able to find a discussion about this....

 

[jeepdreamer]

Guessing you have a 4.0 in the TJ as the Rubi's never got the 4cyl IIRC. Anyway... there really isn't much to gain from a non stock cover on the 4.0. The older 4.2/258 was a different animal and a new cover is almost a requirement if it was plastic. But for yours... not so much. What you will want to do is get a quality FelPro gasket kit for the later 4.0 like yours. The "newer" 4.0s use both a valve cover gasket that is pretty different from the earlier 4.0s (say 97 and older??Ish??) and it has "bridges" that cross over the head in a couple places. But the important aspect of the better gasket is it comes with the little O ring looking seals that go around the bolts that hold the VC to the head. Without those the thing will leak as if there was no gasket at all. Ask me how I know.
The other thing I'd suggest is to look at your head and see which one you have. There is a casting # on top, drivers side, between the VC and the throttle body kinda. If you have that aluminum insulation on the intake you'll have to pull it back a little to see the number. If it says 0331 you will want to check it once you get the VC pulled off. Just between cyls 3 and 4 they are known to develop a crack. Better to find it know and make plans as opposed to not and having it eat the engine over the long run.

 

[Rubicon]

Thanks for the head's up on checking the head, and the gasket advice. I'll definitely look at the head closely!

Any thoughts on whether or not an aluminum cover would withstand warping any better than the stamped steel? Also, the mfg website says that the aluminum helps "quiet valve train noise" - not that I can hear much of that with the top down running freeway (highway) speeds....

Won't know if my existing cover has any warping/damage until I get her back from the shop (she's in having a tranny leak and another oil leak fixed)...

 

[jeepdreamer]

Helping is what Jeeps are all about.
To be honest, I would be surprised if your factory VC was warped or at least enough to cause an issue. Like I mentioned, the early ones may have had issues (Most 258/4.2s) but I think Jeep got it pretty right with the 4.0. The early 4.0 (Renix through say 97ish) had a thick aluminum valve cover from the factory. The later ones got the formed steel one with the bolt hole seals etc. And while the early ones could simply be sealed with a bead of RTV if you didn't have a gasket handy, this will not work for the newest gens.
If you want to replace your cover that's up to you. Will it reduce valve train noise? Maybe a wee bit but unless your building a stealth jeep and can find a way to eliminate all the other noises inherent to a mechanical objects in motion. So I call that idea false... or at least not worth the money. And if your valves and rockers are making so much noise that its an issue... maybe you should check them instead? lol
If you clean the VC thoroughly and install it correctly you should not have any issues with it warping. Don't crank down the bolts Gorilla tight... just follow the factory specs and sequence. You may find the one that is rear most a bit of a PITA but don't let it stress you out. A universal (swivel) joint on a ratchet extension is usually enough to get to it.
Good luck and post up if you need to know anything else. There are some wise old Jeepers on here and all are usually willing to help.