oil on plug threads

i pulled the plugs on my 200 six to oil the cylinders for the winter. When I pulled the plugs the threads were soaked in oil and it looked like the oil was coming from the valve cover. there was also oil on the head bolts on the exhaust side. I had replaced the valve cover gasket and also put a sealant on the gasket last year. The valve cover is a chrome aftermarket that was on the car when I bought it. could this cover perhaps not be stiff enough to give a proper seal. Another thing is how would the oil go past the plug seal? Could the oil perhaps not be returning to the pan fast enough and filling up the valve cover. the head was rebuilt and when I put it back on I poured the oil in with the valve cover off and it seemed to go down quickly. Any suggestions would be appreciated.

8) ok first, the valve cover can very well be the source of the leak in a couple of ways;

1: the gasket failed. if it was cork it can dry out and crack, if it was rubber it can be pushed out of place during installation and normal day to day operation.

2: the valve cover rail, especially near the bolt holes, can be bent or otherwise warped thus not allowing the gasket to seal.

as for the oil on the plug threads, that probably happened when you pulled the plugs. oil in the plug wells ran down on the plug threads as you were pulling the plugs out. this is rather normal. it is also possible that the engine is blowing oil in the combustion chambers with enough force to push the oil up the plug threads, but unless the plugs themselves are oily, i would no purse that line of thought.

one more thing, sealant doesnt really stick to chrome very well depending on what sealant you use. and for the record, i use sealant only to glue the gasket to the valve cover for installation, and for chrome covers i use 3M weatherstrip adhesive, and only enough to get the gasket to stick in place.

Gasket is cork but only a couple years old. Of course the car isn't driven a lot so quite possible. Should the bolts not have a special washer? There is only a normal washer on these ones.

mannella":2mf71a9d said:

Gasket is cork but only a couple years old. Of course the car isn't driven a lot so quite possible. Should the bolts not have a special washer? There is only a normal washer on these ones.

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since the car doesnt get driven much, the cork has dried out and cracked. it doesnt matter the age of the gasket since it was pulled from the package.

you can get load distributors for the valve covers, they are basically a washer with wings on them to distribute the bolt load in a wider area. something like this;

http://www.summitracing.com/parts/mor-68510/overview/

Thanks

I used to have this happen with a chrome valve cover as well. Sealed and resealed, sometimes with better sometimes with worse results. One day I found an aluminum valve cover (mine's an Edelbrock, Classic Inlines makes them now) and using it solved this problem. I use almost no sealer with my aluminum valve cover and it doesn't leak down into the plug wells at all.

8) yeah, for some reason chrome just doesnt like to seal sometimes. i have always had issues trying to seal chrome water necks, even the ones that had "O" rings designed to be part of the sealing system.