Hi Henry - tell me about it - valve cover leaks are easy - right? I have just rebuilt a Vw Turbo Diesel and I maintain all my cars - but this stupid little gremlin is driving me nuts. The only thing I can see is that the valve cover just covers the head to the edge - there is no piece of head extending past the valve cover gasket. The rubber valve cover gasket pushes onto the bottom of the valve cover and goes up the side of the cover by about 1/2" both inside and out for a good seal. The sealing surface of the gasket is flat and about 3/8" wide. On the aftermarket one there is a round rubber bead about the height of a pencil lead molded into the bottom face of the gasket and about 1/16" in from the outer edge. If this bead is not grabbing the back of the head - I believe that is causing the drip. That is why I am trying to find out if a Mercedes gasket has another molded bead 1/16" from the INSIDE of the bottom of the gasket - as if it did - it would definately seal for sure. Like I said - a stupid problem. I don't want to use silicone unless it is absolutely necessary. The car was designed to work without silcone on the valve cover gasket - and by gum - it WILL work without silicone - or I will die trying!! The problem of being a purist!!!