Ordered a replacement plastic cover off eBay and it has two unneeded holes for hold down bolts on the top of the valve cover. Looking on eBay all the 1983 replacement pictures show the holes. My plastic cover has holes but not those 2 additional holes. I know it's the stock cover. I've seen threads that talk those holes so I understand some jeeps needed them but mine doesn't have that set up. What am I missing/not understanding? Nothing is ever simple when working on a jeep!
Thanks for the help, Joe
01-31-2013 09:43 PM
Not sure what holes your talking about.,Could they be the ones for the air cleaner? Some cj had the air cleaner bolted to the valve over, some did not, depending on whether they had the brake booster.
01-31-2013 09:58 PM
My 258 did not have the two rocker arm studs used to hold the valve cover on. Thats what the holes are for ive discovered. I guess they don't make my style of plastic cover anymore. I'm trying to decide if I want to buy the rocker arms with studs $12.00 or return the plastic cover and go the aluminum and tap two holes mod.
only in a jeep cj
01-31-2013 10:03 PM
The OEM plastic covers did not have them that I know off. It was later when it was determined that due to the heat on the plastic, they all bow, lift and leak....so a retro fit was used where two of the rocker bridges were replaced with ones having a threaded stud to allow downward force to help seat it better. (to me, it just makes the sides bow out more). The new cover didn't come with the stud bridges?
01-31-2013 10:46 PM
Nope. They will sell me them for $12. I'm trying to decided if I want to just buy an after market aluminum or make this plastic one work by just buying the rocker arm studs. So the rocker arm stud mod is a fix that isn't too good?
only in a jeep cj
01-31-2013 11:22 PM
The only way Ive gotten the plastic valve covers to not leak (for a while) is to do two things. Don't use the rocker studs and just seal up the top holes with a bolt and rubber washer...or whatever. Next is to degrease and brake clean both the bottom of the cover and head surface thoroughly. I ran an even bead of thick RTV around the valve cover bottom in the groove and allowed to the fully cure. It was about 1/4 tall. The next day, I ran another thinner layer on top of that and installed the cover and only tightened it enough to slightly compress the cured seal...yes, I used no other seal or gasket. Allow this to cure as well. This worked great for me and lasted a long time. BUT it does not compare to using an aluminum aftermarket valve cover. This would be my first choice.
02-01-2013 10:43 AM
My 82 factory cover had the 2 holes and 2 of the rocker bridges had studs on them that went thru the holes. When I switched to a Aluminum cover I cut those studs off. Maybe a previous owner did that to yours as well.
02-01-2013 12:07 PM
02-03-2013 09:57 AM
Update. Do not buy the cheap plastic cover.
The holes don't line up and you end up screwing with it to make it work. It's installed now and of course it's leaking. Fortunately only a small amount forward and so far it doesn't seem to be causing a problem. If I had it to do again I would bite the bullet and spend the money/time required to tap holes etc (as many on this forum have recommended) and just buy a quality aluminum. I'll leave this for a few years just to get some use out of it but, my next cover is aluminum.