To seal or not to seal? (Valve cover/half moons)

[klylor10]

I have been searching around a fair bit on here and found some conflicting information about whether or not one should use sealant on an OEM valve cover gasket. I've read everything from some oil on each side to sealant on both sides. Hoping for some sort of conclusive thing, but maybe I am doomed not to have it.

Any thoughts?

Also, what about new half moon seals? Sealant or no?

Thanks

[Sandy]

Actually both grease and sealant. I do the valve cover side with a very thin film of a non hardening sealant and the cylinder side a light smear with grease. That way next time you remove the cover you're guaranteed that the gasket will come off cleanly with cover.

[chuck hahn]

They are metal covered with thin rubber. First time they are used the metal squishes and takes that form and it doesnt spring back. So, if your gonna reuse them seal them.

I use a thin smear of Threebond 1184 in the head recess and across the tops of the half moons and extend it a little past the edges of the head and half moons meeting points. As youll see on the tube it is a SEMI hardening agent and it will seal them leak free.

New ones generally dont require sealing as they havent been squished yet..

[eil]

There are a lot of ways to go, and to a degree it comes down to personal preference. I myself use a very thin smear of grease on the gasket and a thin coat of RTV on the round portion of the half-moons. No leaks yet.

[Grimly]

Actually both grease and sealant. I do the valve cover side with a very thin film of a non hardening sealant and the cylinder side a light smear with grease. That way next time you remove the cover you're guaranteed that the gasket will come off cleanly with cover.

This is golden advice. <four thumbs up>

[chuck hahn]

I think he actually posted where he puts the sealer and grease in reverse order. Least thats the way i read it.

[Grimly]

Lightly stick the gasket to the cover - the gasket comes off with the cover and can be re-used. Stick the gasket to the engine, you're guaranteed to wreck it when doing the work. I've tried grease on both sides, but 50/50 results on re-use; same with dry fitting.