Oil leaks and crankcase pressure

[4rsfed]

Just did a rebuild last summer and got a couple of defective valve seals on the rebuilt head. Just finished getting it all back together now have some serious oil leaks, it leaked before especially the pan, now seems worse than before. The mechanic said seems like building crank pressure. Compression tests ( warm engine, dry test only) where all at 148 to 150. The PCV, valve hose from manifold reads 20 in of vacuum, the elbow fitting on the top left which is supposed to draw air from air cleaner, appears to blow air out and idel however when rev it stops. Any ideas as to where the pressure can come from. The car was tuned at a qualified garage and runs like a top. But this oil thing is getting me down

 

[DSMcamaro]

Clean up all the oil and then start it up and let it idle. See if you can spot the source of the oil leak. If it doesnt leak at an idle, you know its probably a leak somewhere that requires you to build oil pressure to make it leak. Find the source and go from their.

 

[4rsfed]

Thanks for the reply but it leaks from the pan, around the main seal, even oil on top of intake manifold, a bit down by the oil filter. If seems to leak bad only at high speed so this indicates to me a pressure build up. Any ideas on what would cause the crankcase to build up pressure.

 

[vintagemuscle]

Thanks for the reply but it leaks from the pan, around the main seal, even oil on top of intake manifold, a bit down by the oil filter. If seems to leak bad only at high speed so this indicates to me a pressure build up. Any ideas on what would cause the crankcase to build up pressure.

possibly a bad turbo seal is causing the excess pressure in the crankcase.

 

[amp9211]

My car is doing pretty much the same thing, only it is leaking from the front of the engine (near the exhaust manifold). I am very interested to see what could be the cause of this because it has been haunting me for a few months now and Mobile 1 gets expensive to replace.

 

[Denji]

Hey, i just wanted to tell you that the same thing happened to me, i was getting a mystery leak only sometimes, a new pcv valve solved this problem. I cant believe that the oil stopped leaking with a new pvc valve, it must not have been changed in the whole 140000 miles i had it, it worked kinda, but it would stick easily.