so i have the Mr Gasket chrome valve covers and they are leaking. my question is what gasket should i be using on them rubber or cork and should i use RTV on both sides of the gaskets to get a good seal because i'm tired of these leaking on my headers. it's on my 351w. oh the covers are new and i got the little spreaders for each bolt to avoid the over tightening

 

Make sure the valve covers are perfectly true and flat. Place them on a flat surface to check. The trick with valve covers is, if they are too tight they will leak. Every. Time. So, people tighten them down even more!

Cork gaskets work fine, the trick with those is they can't be too tight either. Use RTV on one side only. I like to have the gasket attached to the valve cover. Maybe it doesn't matter, I dunno. Tack up both the valve cover and gasket, then install and let cure thoroughly.

Then coat other gasket surface with clean motor oil only and let it soak in for a while. Tighten "finger tight" with a socket and extension, and then with a wrench a little bit more. This is not intuitive, so people start reefing them down to 20 yard/tons and that's that. The spec is maybe 50 inch pounds or something like that.

Usually after engine operation, you might want to tighten juuust a smidge more after it cools down, if necessary. They will not leak this way and the valve covers can be popped on and off many times using the same gasket. Just re-coat the gasket with clean oil each time. Useful if needing to periodically adjust valve lash and things like that.

 

ok! you say use the cork gaskets... i have those rubber with the steel inserts from felpro but i'll get the felpro cork ones.. thanks for that tip i'll be doing this one day this week or this weekend coming up...

 

Well use what you have... they work fine too I'm sure. But the installation may be a bit different, not sure on that part.

 

Try this.

With the rubber or rubber with steel core, de-grease all sealing surfaces with acetone or lacquer thinner. Probably best to avoid using that on the gasket so just wipe it dry with a new towel. Put valve cover on, get a socket and extension, and just get them as tight as you can by hand WITHOUT a ratchet. Works for me every time. No sealer, no mess, no BS.

 

You my never keep them from leaking. How do they compare with the factory covers? If they are thinner and cheaply made, they may not seal. Some of this stuff is junk. Also check out where the PCV valve goes in the cover on the factory covers and on the chrome covers. If it's just a open hole on the chrome covers with a grommet, your engine will use oil badly. If you look at the factory covers they have baffles at the holes to try to separate the oil from the air going through the system and into the intake.

 

ok! well like i was saying i'm gonna try to get to the local pullapart if the rain here lets up to find some better valve covers off a 5.0L V8 explorer which the heads came off of or a mustang. if not then i'll try the cork gaskets and just let them sit up clean everything off again to ensure a proper seal and hope for the best.

 

well i used the cork gaskets and i cut them damn tabs off. i used gasket tack spray on one side to hold it to the valve cover and put them puppies on. so far no leaks...