Last night I pulled my valve covers so that I could replace the leaky old gaskets and polish my valve covers while I was at it. I noticed carbon deposits on the side opposite the lobe of the cam. It seems that the rocker arms are not coming up all of the way to contact that side of the cam. I assume this would be caused by dirty valves and deposits in my head. I am tempted to just run it until it breaks and put lots of Techron in my fuel. My ride is a 94 TT with well over 100 K miles on her.