Oil from VC Vent

[MazdaSpeedSix]

Heyy guys back again with another question. I searched and couldnt find a solid answer to my problem and i wanted to verify.

I was running fully bolted and tuned.. I had the car sit for a week while i changed out the clutch, Spark plugs, oil, i powder coated my valvecover as well. So this is my problem, i have a breather filter on my valve cover vent and it just spews oil through it. I am running 20 PSI and 1-2 gear dips to 9 AFR readings. (Need to calibrate intake and disconnect SWAS and check again) but thats what i am dealing with. Any ideas?

My thoughts were getting an OCC with a check valve but that wouldnt fix all that oil pushing past the vent.
PCV valve not closing all the way under WOT, pressurizing the crankcase and forcing oil out into the breather. (Keep in mind the car has 15k miles)

[Lex]

A lot of oil coming out the VC vent either means a clogged PCV system or a lot of blowby. Check the PCV system and also do a compression and leakdown test. Adding an OCC if you have a lot of oil coming out of the VC vent is not addressing the root cause of the problem.

[2012FailWheelDrive]

Originally Posted by Lex A lot of oil coming out the VC vent either means a clogged PCV system or a lot of blowby. Check the PCV system and also do a compression and leakdown test. Adding an OCC if you have a lot of oil coming out of the VC vent is not addressing the root cause of the problem.

How exactly can you check the pcv system? I am having the same problem and my compression results were still in spec.

[MazdaSpeedSix]

Compression is just fine. Leak down turned out just fine. PCV valve is my only guess but i really dont think so. I have a small breather filter on the valve cover and i sealed off the intake port. At WOT it just leaks a good amount of oil. not an insane amount but noticable. Before i changed the plugs and the dirty breather and powdercoated the VC it had no problem. Now it leaks... Isnt the breather vent suppose to relieve the crankcase pressure? Dipstick isnt popping out and no oil in the IM.

[atvfreek]

Originally Posted by MazdaSpeedSix Compression is just fine. Leak down turned out just fine. PCV valve is my only guess but i really dont think so. I have a small breather filter on the valve cover and i sealed off the intake port. At WOT it just leaks a good amount of oil. not an insane amount but noticable. Before i changed the plugs and the dirty breather and powdercoated the VC it had no problem. Now it leaks... Isnt the breather vent suppose to relieve the crankcase pressure? Dipstick isnt popping out and no oil in the IM.

What were the actual compression and leak down numbers?

[MazdaSpeedSix]

Compression
170
170
160
173

[atvfreek]

Originally Posted by MazdaSpeedSix Compression 170 170 160 173

Those numbers are close to spec at elevation. Do you recall the leakdown percentage? May oir may not have an issue creeping up in cyl 3.

Once my rings started taking a shit, I had 165ish across the board but 13% leakdown in all cylinders. Car still ran great and had no loss of power, but the blowby was getting worse and worse.

I stuck a vented OCC off the VC vent and even added a second VC port to keep the oil contained after extended wot pulls. It got to be a PITA which led to a rebuild.

[Lex]

If a lot of pressure is getting into the crankcase, it does vent through the valve cover under boost but it also pushes some oil out with it if the pressure is excessive.