Im from England and I have a Japanese import Lancer evo 4 which is standard.It has developed a fault whereby it blows the dipstick partly out of its tube and then blows out large amounts of oil.I imagine this is caused by excess crank case pressure?I have located what I think is a breather valve to the rear of the rocker cover and this is clear.Anyone know what the problem is?The car runs perfectly in every other way and it takes 1 or 2 minutes for the fault to occur.I am sure I am missing something simple but I am struggling to get any data on the crankcase ventilation system.

 

Blocked/sluged return?

 

positive crankcase ventilation, it vents off excess pressure in the crankcase. since you never get 100% compression, there is always blowby, so the pcv gets rid of that blow by. You can also have worn piston wrings that is causing excessive blowby, or a blown headgasket.

kent

 

Well considering it is an EVO 4 you are missing the most simple problem off all. This is common on the DSM's too. 99% of the time the engine is in great shape. The rubber on the dipstick simply gets hard and no longer seals. This allows even a small amount of blow by to blow the stick out. One easy fix is to simply put a small crimp in the tube so it holds tighter to the dipstick

It might still be a good idea to do a leakdown test just to be sure.

Take care,
David Buschur