IXLR8

Because heat exchangers are not 100% sealed and if you have pools of oil sitting atop the heat exchangers, as more oil leaks onto them, the oil running off the sides makes it into them via the ends where the exhaust pipes exit the heat exchangers.

When I got my low mileage 1995 993 in 2009 when it was 14 years old, the valve covers were oily due to old and original seals, the original spark plugs had never been out, so not wanting to pi$$ a$$ around, I removed the complete exhaust system, replaced all 12 spark plugs and all four valve cover seals while giving it all an extremely thorough cleaning.

There was oil within the heat exchangers upon removal. I used a commercial water based degreaser till the insides there were like-new clean, sloshing it around. Of course this is pointless doing if your valve covers still leak. I've never had valve covers leak after an initial replacement. Do it right; life is too short to do things twice.

mferris

Thanks. No more smoke, I just don’t understand why I can’t seem to get all the drips resolved even with new valve cover gaskets carefully installed and torqued. Trying new valve covers (and gaskets) now. If I had the guts or time I would drop the engine and reseal everything…(timing chain covers….)

Matsuzaka

I think my replacement ones look great.

IXLR8

Not that I would replace mine, but who makes them and what does a set of lower and upper valve covers go for?

The trouble with metal is it makes a good ground for leaky or ignition wires on their way out, especially in rain.

Matsuzaka

[QUOTE=IXLR8;19193314]Not that I would replace mine, but who makes them and what does a set of lower and upper valve covers go for?

Mine are Rennline, got mine from Pelican and they were $300 per pair, lower or uppers, but I think they’re bit more now.