Post by
dattodude »
https://forums.nicoclub.com/dattodude-u30125.html
Sun Jan 27, 2008 7:54 pm
under boost...PCV shuts, and only exhaust side vents, and galleries in rear of head allow pressure in intake rocker cover to vent via the exhaust cam cover..
So Niscort is right to say that both should be vented. Especially if you do get a lot of blowby, and run a high oil level.
My engine is rebuilt, and with the 'aussie way' of hooking up breathers, mine doesn't get a drop of oil in a catchcan hooked up to the exhaust side, and feed back to the pre-turbo intake piping.
ps.I temporarily didn't vent anything and piped everything to the PCV, which is fine on NA. But causes dipstick-missing related fires under boost...
Maybe you are just running too much oil,
OR
There is a breather hose that goes from bottom/back of intake cam cover, leading to the oil filter area. This pipe can get blocked with gritty carbon crap, and this can stop the breathers working properly under boost.
Getting to the pipe is not easy. And will involve a lot of swearing. Also note that the silicone hose connected to it is 1.25 inch, and hard to replace if cracked.
Chris