Looking for Truth about Valve Cover Gaskets!

It seems that there are a variety of opinions on the subject of valve cover gasket installation. I just took my cover off due to a big leak down the back of the engine. My PCV valve and hose are in perfect shape. I made the valve cover as straight as I can. My factory service manual says to put a new cork gasket on the cover and tighten to 50 inch/lbs. In this forum and others, I have read of methods using RTV sealer, permatex, "the right stuff," etc. with a variety of application methods. Some are passionate about installing the cork gasket dry only. Can anyone help me sort this out? This time I want to do this right, haven't put too many miles on this jeep and this is my 3rd valve cover gasket!


Thanks for your input!

 

Well, I'm not a big fan of cork gaskets. The factory supplied rubber gaskets, which work pretty well. Felpro may sell the rubber gaskets, but last time I looked they supply some kind of composition gasket.

I have never seen a steel 258 valve cover that did not leak a little. Even brand new Jeeps with that valve cover would have a wet spot or two after driving them a while. Not a drip, but a seepy leak that would attract dust and dirt.

I can tell you how I'd do the gasket, but I can't guarantee that my method is the best or that you won't have a little leakage.

I prefer to glue the gasket into the (carefully straightened and verified flat with a straight edge) valve cover. Then I use a coating of silicon sealer (like Permatex Ultra Black) on the bottom of the gasket. Don't overtighten. I use a nut driver or 1/4" palm ratchet to install - don't overtighten. Apply and let dry for a day before starting the engine.

 

Yeah, the main problem seems to be that there are not enough bolts to cover the span between holes. I agree with making sure the flange is straight and the holes are not caved in.
I use the brown Permatex form-a-gasket sealant (1A) and glue the cork gasket to the cover good and a light,thin coat for the head side and torque it down with a torque wrench. Then wait 24 hours before firing it up.

 

I usually glue the gasket to the cover with 3M weatherstrip adhesive ad put a thin layer of rtv on the head side. tighten by hand till the bolts are snug and it should be good to go.

RSN

 

put em in dry.... if you use cork.. it's designed to absorb some oil and expand sealing the joint..

BUBBA

 

Since the cork is designed to expand with oil absorption, is there any harm in adhering the top and bottom cork to the valve cover and cylinder head while leaving the sidewalls of the cork exposed?

 

The factory could have used a cork gasket, but chose to use rubber. The factory gaskets are the same as Fel-Pro VS13839R. I expect the Fel-Pro cork gasket is actually ground-up cork and rubber, and not a 100% cork sheet gasket. I would avoid any gasket that is 100% cork for this application. There are two Fel-Pro cork gaskets that fit, VS50258C (thick) and VS50186C (thin) - technology has advanced since these cars were new, and the newer gasket material may be superior to the old cork or rubber gaskets.

Note that Fel-Pro supplies a good product, and I believe they would not offer a particular type of gasket if it were not suitable for the application. Each of these gaskets is less than $10 each, and changing a valve cover gasket is quite easy. Pick one and try it, and if it leaks, try the other. However, if it does not leak, I suggest you leave it in place and curb your curiosity about which is better.

IMO glueing the gasket into the valve cover should only help - if you don't glue, the alignment of the gasket between the bolt holes may be difficult, and especially if you use a slippery gasket cement on the other surface, the gasket may squirt out from under the cover and not seal.

Don't overtighten!

 

Thanks for your help. I will take your advice and give it a shot.

 

So, Tim, let me see if I understand. You're saying DON'T overtighten?

 

Try these.

http://www.realgaskets.com/files/automobile.htm

Install dry, both sides.

DO NOT OVER TORQUE:evil:

Defiantly straighten the cover as above, or change to cast alum cover. Load spreader bars help.

I like to install studs in the head, I use allen set screws, an inch or so long as needed for a stud, and a nut and star washer on the cover. Locktite the stud in---red not blue.

Studs keep the gasket in place while fitting the cover.

Good luck.

P.S., dont overtorque the hold downs.

http://www.magnalabs.com/realfasketfaq.htm