Intermittent crankcase pressure issues

Deceus said

Fair point. I'll be honest I'm not even really sure what purpose that fulfills. I saw the diagram but what does that hose do that a breather and pcv doesn't? I know there's no significant vacuum at WOT so the PCV isn't as effective but wouldn't that be the same case at the air cleaner?

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Actually the pcv valve is almost fully closed at idle and high vacuum. The pcv valve is fully open and functioning at wot. When you did your leak down test did you listen at the exhaust, intake, valve covers, and dip stick tube to see where the air was leaking to? If you redid your pcv system did you use oil resistant vacuum hose? Fuel line hose is for pressure and will collapse under vacuum witch is how the pcv system works. Also make sure the pcv valve is sealed to the grommet and the grommet sealed to the valve cover good.