I have a 91Z28 supercharded with 8lbs of boost. Recently, i have noticed oil on the top of the valve cover. I replaced the pvc valve and it had no effect on the oil running on to the valve cover. I have no idea what is going on? The car runs fine, oil psi is normal. I changed oils in april from amsoil synthetic to mobil one synthetic only because it was easier to purchase. Any Ideas what could be causing this?

 

Could be blow-by? That's when compression gets past the rings causing the crank case to pressurize. It could be from your change in oil or a sign that the rings are craping out. I haven't run a supercharger before, so maybe that has something to do with it?

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1988 L98
Vette Heads/no EGR
SLP Headers/Y-Pipe
ARAP bin

 

I Think you are on the right track. I plan to do a compression check on wensday and then add oil to each individual cylinder. I am PRAYING that it is a valve guide! I changed my rocker's from a 1.5 to a 1.6 roller tip about 6 months ago and hoping that maybe..Just maybe the geometry change is whats causing the blow-by? We'll see soon enough..i hope