Lifetime Premium Member
Join Date: Apr 2011
Location: SO CAL...Huntington Beach and Rancho Cucamonga
Re: Finding Vacuum Leaks
I found a vacuum leak at the intake to head gasket by first checking the plugs. On short runs or lots of idle time showed oily, but the oil cleaned up on long runs and the plugs looked lean compared to the others. So I tried to figure out WTF. I pulled the PVC and plugged it. Then sprayed carb cleaner into the valve cover, after a few seconds the rpms would increase slightly. That told me I had a vacuum leak or bad valve seals/guides and maybe sucking oil at other times. Pulled the manifold and found the leak at the gasket. The intakes were pulling vacuum and oil through the lifter valley.