Valve cover gasket

[cscarlson]

Had to put new valve cover gaskets on my corvette but the new ones leak on the bottom side. is there anything i can do to fix this short of replacing them again?

 

[C3forME]

Did you make sure that both the cylinder head and the valve cover surface were 100% clean and free of any pieces of the old gasket? 99.9% of the leaks afterwards are usually due to the surfaces not being cleaned properly before installing the new gaskets. Also did you adhere the gasket to the cover first and let it set up so that it doesn't move when you go to put the cover onto the head? And lastly did you tighten them enough, without over-tightening them. Sometimes if you over- tighten them you can bend the covers and then they leak.

 

[cscarlson]

YES, Yes. YES... I did all that and still have a leak. anything i can do short of replacing the valve cover gaskets again?

 

[iron cross]

Glue the gasket to the valve cover with 3 M weatherstripping cement. Once this is done, the gasket is guaranteeded not to move by bumping rocker arms and springs ect. Merely use a light grease on the head side and you can use them over and over. NEVER use that blue junk or any kind of silicone.

 

[The Car Whisperer]

Why not Silicone? I've used the red silicone and the blue silicone in the past on valve cover gaskets and never had a problem. I know you shouldn't use silicones anywhere in the intake system because residual silicones can poison your O2 sensors, but I have never heard anything bad about using it on the gaskets exposed to the luricating system.

 

[iron cross]

The first problem with silicone is that it really never hardens to make the gasket stick as well as the 3M cement. Another problem is that it brakes off and goes into the oil pan plugging the oil pump screen and that is really dangerous. Thats two good important reasons, keep it out of the oiling system. It is often used as a substitute for a gasket from the factory however, but we replace many engines and the old cores are usually filled with the stuff and lodged in the oil pumps. You can do what you want, but it will never be used in any of my stock, gas or fuel racing engines, nor those we replace for our customers. A position in favor of 3M is also that the overhead covers are off our engines after every run and the 3M allows us to reuse the same gasket over and over as they are almost permeant that way and one less problem between rounds. Hope this helps as sometimes a person could get confused and wonder why if not familiar with it`s use. C3forME covered the preparation which should be done first, but i`m sure you already did that.

 

[The Car Whisperer]

I'll stick with the silicone, when used in the proper amounts on engines I have built and rebuilt I have never seen a problem. It must be used sparingly or of course it will create problems.

 

[lt4 gs]

I realize that this is older than dirt. I prefer the non hardening Permatex stuff....never had one leak yet. Ask the Chick our resident tech..

 

[The Car Whisperer]

I have also used that. Never had a problem with it either.

 

[cscarlson]

Where do you buy this Permatex stuff..?

 

[Jack]

Where do you buy this Permatex stuff..?

I realize that this is older than dirt. I prefer the non hardening Permatex stuff....never had one leak yet. Ask the Chick our resident tech..

Just about any local parts house should have it. I agree 100% w/ lt4 gs ... permatex non-hardening on VC side only of gasket ... if it still leaks put some on head side too. Make sure your cover rails are straight ... especially if stamped VC. PNH looks like dookie-in-a-tube ... good as gold. Been around forever ... it’s what everyone used before the advent of silicone ... still best for some apps. Works great on water pump mounting flange-gasket too. The pnh will hold gasket in place on VC very well ... & is nowhere near as hard to scrape off as gorilla snot (3Mwsa) ... but is more difficult to remove than silicone. I believe its present-day correct name is “Permatex® Form-A-Gasket® No. 2 Sealant” ... it is not silicone /not RTV. The #1 is similar but it hardens ... #2 stays pliable.
JACK:gap

 

[iron cross]

If you insist on permatex, use #1 it will harden up and the gasket will never be allowed to move because #2 never hardens up to prevent movement by accidently hitting a rocker arm when installing the overhead cover.

 

[CS72Roadster]

Oh Man! You cracked me up with the "gorilla snot"!!

 

[iron cross]

don`t use it on both sides, wheel bearing grease on the head side is all thats necessary. I`ts damn good stuff when used correctly. You use it on both sides, it will never come apart. Just in the valve cover and it can be used over and over.

 

[Enigma]

I've come into this discussion a bit late.

It may be that the valve covers are not perfectly flat.

There are extension bars that you can buy that will distribute the force applied when the bolts are tightened.

The bars are about 6" long, with a slight curve to them that straightens out when bolted down.

They are the same width as the lip of the valve cover.

They stopped the leaking with standard gaskets.

I could take a picture if my description is not clear enough.

Enigma

 

[Gunther]

Hi

What type gasket are you using, the cork or rubber ?
I used SUMMIT's rubber gaskets on my 68 BB original chrome covers , and since than , the left cover is leaking at the aft end.
Never had this problem with the cork gaskets before.
I will switch back to cork as it expands when it gets oil soaked and has some kind of selfsealing effect.

I'm a bit p..ed off about the so called better rubber type gaskets.
Multiple use bu....t !ad

Gunther

 

[iron cross]

The rubber gaskets are not what they are cracked up to be. But 1606 and 1630 performance gaskets by Felpro are a combination cork and rubber and the only difference is the thickness . VS30055C is Felpros cork material. GM also has a very good imprinted gasket with a steel insert used on the LS7 engine. This GM gasket is used without sealers. The Felpros should merely be used with a hard setting sealer only in the overhead cover. I prefer 3M weather stripping cement in either black or yellow, but any hard setting sealer or glue will work. No silicone sealers. This accomplished, you can be sure that the gasket cannot move during installation to the engine. Plus you can use them over and over as long as you don`t use the sealers against the head surface. That would be a no no.

 

[Gunther]

Hello iron cross

Nice car you got. Gongrats.
Actually my dream car, black 62 .:cool
Possibly my next one , when I get my life-insurance paied out.:Silly
62 is my year of birth.

With jealous greetings: Gunther

 

[iron cross]

Thanks Gunther, Wally Knoch