My take on this is the last place a valve cover gasket would leak would be at the compression points. You say "the screws are leaking", I can't see by the picture, but are you really saying the valve cover leaks?
One common mistake is over tightening, Seen it many times. Done it myself. Get a new gasket, use pan head screws with spreader washer. The star washers may have encouraged you to think they are lock washers and you needed to crank down. They are to be slowly tightened to snug. Crisscross pattern. They may need to be re-snugged a few times. Very carefully.
We don't know the history of this leak, that would be very helpful to determine cause. I.E. Out of shape cover or holes that need work as Martin describes. That would be if it has always leaked. Do check the cover, per Martin, for surface flatness and hole perimeter distortion.
If recent a leak........ over tightening/gasket over squeezed, no compression left. Gasket too old...........etc. Looks like you are using a good name brand gasket. Just be sure it's thick enough. Cork has always worked.
There are good gaskets and there are bad gaskets. There are different thickness gaskets. The cover, done properly, will not leak. I would not use any sealer except if the gasket comes out of the package non linear and won't stay on the cover in the right place, it may need a super light tiny dab at the bad spot. Tape it until it stays with screw in the holes. Gasket to cover only.
Why do your screw heads look so white?
Andy, I've seen your posts before. You know what you are doing. My post is just basic stuff, a refresh or a idea jogger. Not trying to be an instructor.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
