Pronto
No amount of evidence will ever persuade an idiot.
- Joined
- Dec 9, 2002
The typical route for lines to a catch can is vacuum block 3/8" line to check valve to catch can to pcv valve. The check valve blocks boost from going into the engine. At least one valve cover has a vent to allow the pcv suck out air from the block at mid vacuum. The pcv is weighted so it will open at a certain vacuum and evacuate the block. As the throttle opens more and vacuum drops the pcv closes. It's supposed to block boost from backing up into the block but they leak. That can pressurize the block and drive oil out the gaskets and valve cover vents.