I got my 1966 chevy with 292 on highway 3 times it seems when it gets above 45 mph the oil comes out as if the crancase gets pressurized could this be the pcv valve the engine does not smoke alot but has not had hard running since probably early 70's has anybody else worked on this problem also have not replaced any gaskets yet but do not have a problem below 45 ps truck feels great on highway no shimmys or shakes only 64,000 on original motor Any ideas or help appreciated Thanks Dave
Yeah, the problem could be a bad PCV valve or more likely the valve cover breather or breather tube into the aircleaner is plugged up.Or less likely is the rings are worn from lack of maintanence causing excessive blowby into the crankcase.
The valve cover cap is not vented and no breather on the air cleaner should it have a vented oil fill cap with a breather on it from what I can see there is no breather on the valve cover.
Yes, the engine needs to have a source of air ,to ventilate the engine and have a exit for crankcase pressure when the PCV valve is closed, like during times of low engine manifold vacuum, heavy loads, acceleration, vented breather cap will work.
Truckedup thanks for the great advice bought a 3 dollar breather cap ended all my problems had it on the highway last night no oil leaks I also tightned valve cover bolts funny thing is I have been around this truck since 1983 and the old cap has been on since then so i thought it was original but the truck had not been on the road since 1978 so it never built up enough pressure to force oil out with its short runs.again thanks
