Need Help! Excessive positive crankcase pressure resulti in RMS leak

[jayadams66]

My car is leaking out the rear main seal from excessive crank case pressure.

I came to this conclusion after fixing the oil pan gasket and it then still leaked. so I started it and sat under there. So in than remembered a car I fixed where someone blocked off all the breather hoses. pushed oil out the seals because of the pressure.

I searched the forum and think I might have found a solution at his thread. in post #7 "Catch can was vta with the OEM pcv valve in place. Had too much pressure in the block." posted by 2.0t03speed
but he doesn't say what he did to fix the problem. and what is VTA mean? Oil leak from weeping hole at pan/tranny joint: rear main seal

I suspect the PCV valve but wanted to get a second opinion. It has a corksport OCC installed on the car. motor was rebuilt bored .020 over. other than that completely stock.

Thank You

[SeeMeGovan]

Oh boy. Quick, before you get railed in the ass for making this your first post, go read the welcome message in your inbox, then read this thread and make an intro post in the new member section.

Next, go over here and read these 2 posts by Matt Damond about PCV's, crankcase pressure and OCC's.

But I'll throw you a bone: VTA is vent to atmosphere, meaning your can has a filter on top that just dumps crankcase/valve cover pressure into your engine bay instead of back into your air system. This can be a dangerous system because your air system actually pulls vacuum to help vent the excess pressure in your crankcase/valve cover and a VTA setups relies purely on the excess crankcase pressure to vent itself. It works much better to have vacuum on one end of the venting hose.

So you need to figure out:
1) What mods are done to your car (mechanical, ECU tune, etc) that might be increasing your boost pressure, or if your engine is old as shit and you have a ton of piston blow-by pressurizing your crankcase like a balloon.
2) What OCC setup you have running (VTA or closed-loop).

There could be a number of things causing you to have excess pressure in the crankcase like a PCV valve caked over with crud so it won't let any air out. It is technically a replace item every 75k miles or so (whatever the manual says) cuz it's just a shitty plastic valve. But whatever the problem is, you need to fix it before replacing any seals or you'll just fuck up your new seals, too.