Off Roading Forums banner

Valve cover: Aluminum vs plastic

3745 Views 4 Replies 1 Participant Last post by  **DONOTDELETE**
Hey folks!

I have an 85CJ7/258 with the plastic valve cover. When I bought the Jeep last year the old cover was cracked, leaking like crazy, etc. I couldn't afford an aluminum one at that time and sprung for the plastic kit from 4WD. It has worked great since, but has recently started leaking and I started thinking that its time for the Clifford aluminum cover.

I remembered seeing one sitting on a shelf at Jack's Jeep here in MD. So I called and talked to them and they recommended *not* to go with the aluminum cover! He claimed that they still leak and that the baffling on the inside is flawed and allows oil to blow into the air cleaner.

I've heard nothing but positive testimony about the Cliffird valve covers up to now. I also thought that oil in the air cleaner was more a vent problem or a ring problem rather than a "baffle" issue.

Has anybody out there with the later model CJs switched to aluminum? I'd like to hear some opinions: How long its gone without leaking, oil in the air cleaner, any problems, etc.



1 - 5 of 5 Posts
The factory

The FACTORY plastic cover is the only way to go. The aftermarket aluminum covers look neet but will leak quicker than the factory plastic one. They don't
have proper baffles which allows oil into the air cleaner and the pcv valve will start to drink mass quantities of oil. they also have a puch in oil cap that sits over the front rockers that has a tendancy to all out after the rubber hardens in a few months. The rear of the cover also has a yery thin section near the rear head bolt where the gasket (special) tends to slip outof place. Did your kit come with the updated headbolts and clamp washers? Did you clean off the surface of the head spotlessly? You could also try re-sealing the cover you have now using a high quality rtv sealer and making sure the head and cover surfaces are 100% oil free and letting it cure overnight. The best solution to this problem is to replace the head with a late YJ 4.2l one that has the factory aluminum cover. All other parts are the same. Its a bolt on for 86 & 87 engines with 1/2" head bolts. The 81-85 used 7/16 head bolts so spacers may be needed to keep the late head centered on the block. I work at a Jeep dealer that used to sell the aftermarket covers but I won't use them any more as I can't guaranty them not to leak for the customers. I hope this helps.

did you

See less See more
Stay away from the the Clifford aluminum cover. I didn't have a problem with it sealing, but the casting is
poor and I suspected it when I started backfiring through the carb. Sure enough there were marks on the
inside where the rocker arms were scraping on the valve cover. It was returned to Clifford for replacement
but they just took a rotary tool and tried to relieve it. I still had the same problem when it came back.
Clifford knows about this problem, but keeps selling them. I don't buy anything with the Clifford name on
it. I still have it, when somebody with the right engine really irritates me I'll sell it to him cheap to get my


Another reason I was all too glad to yank the 258.

I had the Clifford on my engine before I replaced the it with a Chevy 350. I dont think I would recommend it. It requires tapping the head which Im completely against. On the same note.... plastic is a joke to use as a valve cover.

There is another company that makes an aluminum valve cover. This new one is polished aluminum and it isnt cast so Im sure has tighter tolerences. Look for the advertisement in the back of the latest 4WD & Sport Utility magazine for info. If you dont get the mag let me know and I'll dig it up for you.


Larry 85CJ7,350TBI,T19
See less See more
I have a factory Aluminum valve cover on my 89 258. It seems to be working great for me. Doesnt leak at all,(I have a spare gasket in my basement for a while now, but havent had to use it yet). It also seems to quite down most of the rocker noise so you cant hear it to much. I have had no oil in my air cleaner when I check it, so there is no baffle prob. on the factory aluminum cover. I would recomend checking into it from your jeep dealer, it prob will cost more than the Clifford or 4wd Hardware aluminum cover.

1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.