simplyconnected (5/10/2009)
Use RTV, but get it from an auto parts store, and get the correct kind.
At the factory, we commonly use RTV with NO gasket (normally on cast parts like oil pans). RTV comes off VERY easilly (with a razor blade), and may be re-applied whenever you like. You don't need a thick layer. Spread a coat onyour dry gaskets, let it 'skin over' for ten minutes, THEN applyyour valvecover. Any imperfection will be sealed and the skin provides a cushion. The remainder simply squishes out. You shouldn't have to retighten your cover nuts.
- DaveI'm sure you mean what you say, but GM burned up a lot of vehicles using this technique. In the 80's, GM started using the RTV technique to seal intake manifolds and the like. They also started painting their engines black so that the oil leaks wouldn't show up so bad. Then came the outbreak of engine fires.
I owned an 86 Suburban that burned to the ground while my brother was driving it through the desert. There's no doubt that the leaking valve covers were the cause. And, as we speak, GM is recalling its Grand Prix 3.8L engine for oil leaks that lead to fires.
Personally, the use of RTV as a gasket replacement is the sign of sloppy work. I realize how harsh that sounds, but I don't have much patience for self-defeating 'short cuts'.
Use a cork gasket on flat valve covers.
Best regards,
Paul Menten
Meridian, Idaho