Rubber or Cork valve cover gaskets?

[lbrowne]

I used new rubber gaskets when I did the heads on my truck. The driver side keeps leaking oil.

I tried loosening the bolts incase I had them too tight, and retightening after driving it for a bit. Still leaks.

The truck hardly leaked a thing for a month after I did my heads, now it is. I got underneath and I can see it seeping out from the back of the valve cover and making it's way down the back of the motor.

I have a new set of cork gaskets on the shelf... but I was always told to use rubber.

[78 Chevyrado]

If you have them on the shelf go for it.  I wouldn't buy cork, but I'd use em if I had em.  If its still leaking, take the valve cover off and check it to see if its really flat, like on a known flat surface.  tweak it until its flat.  also where the bolt holes are you may need to flatten that area back out as tightened bolts would dimple the area down and ot pull the rest of the flange down enough.  Are you using the spreaders on the bottom bolts?  Maybe a set of wider aftermarket spreaders would help. I pretty much always use em.

The stockers look something like this but aren't chrome.


The aftermarket ones I use look like this

[lbrowne]

I'm using wider spreaders, they were already on the truck. (like your bottom pic, but not chrome)

[bobcooter]

I used the Fel-Pro cork gaskets with the spreaders and have had pretty good luck. The first set leaked some, but I think I put too much silicone on them. On this set I used 3M adhesive and they are working well. It's really important to make sure your sealing surfaces are smooth and flat like Kenny stated.

[lbrowne]

Maybe I'll try pulling that valve cover this weekend, for some reason I remember the driver side valve cover being a pain to remove and get back on.

[beastie_3]

I have tall covers and the booster gets in the way.

[Captkaos]

You are tightening down on the cork gasket to much.  If it is leaking you can never "loosen" it to make it stop.  You have to get it tighter.  The cork gaskest aren't meant to be clamped down on.  I get them cinched down by had (no ratchet) and then put a small turn on them with tension.

[lbrowne]

I have the rubber gaskets on there right now, that's what's leaking. I thought you could overtighten them and cause them to leak.

Maybe I'll throw a cork gasket on there after I check the mating purposes.

[HAULIN IT]

Fel Pro makes some with a plastic "framework" with a raised sealing bead that work well & are reusable. They are a bit costly (about $25), but really should be the last ones you'll need. Lorne

[Dr_Snooz]

The torque spec on those valve covers is 48 in-lbs. That's not far past wrist tight. If you didn't use a torque wrench, chances are good that you over-tightened them.

[Irish_Alley]

I had a Guy at autozone once get two sets of gaskets I looked at him he said he puts both sets on at once and has never had one leak. Never found out how it turned out nor have I tried it

[lbrowne]

The torque spec on those valve covers is 48 in-lbs. That's not far past wrist tight. If you didn't use a torque wrench, chances are good that you over-tightened them.

45 INCH pounds? !?!  I must have them too tight, yikes!

[Psycho71]

 I like the valve cover gaskets that are rubber with the steel shim in the middle of them. They seem a lot more forgiving to me. I rtv them to the valve cover, then turn them gasket down on a flat surface. Let them sit overnight, then install the valve cover using the spreaders described above, and t-handle bolts. Just good and snug. Then, as a habit, every time I open the hood I check all the t-handles to make sure none have backed off.

Works like a champ for me.

[Irish_Alley]

just dont leave the t handles on that can be removed lol

[Psycho71]

just dont leave the t handles on that can be removed lol

Good point. I use the ones that the "T" is pressed in. Not the Cheaper/uglier "Y" handles that will eventually vibrate off driving down the road.