Quote:
Originally Posted by dzenno
Researching further on this topic on other turbo platforms (vw/audi) seem to suggest that vacuum provided by the turbo (so in our case the rear intake tube where the stock PCV hooks onto) is a great source of vacuum and basically a free vacuum pump every turbo car comes with 
In any case this PCV on the N54 definitely needs some research/testing especially as we run high boost/upgraded turbos...crankcase pressure gets really evil up there and if at the minimum the stock checkvalves aren't working as they should it can wreak havoc in various places |
That was one of the weaknesses in the VW/Audi platform.
The stock pcv system could not handle the additional boost from tunes and would allow some leakage and blowby into the crankcase.
You could easily spot it by looking at your oil filler cap......if the oil on the cap looked frothy, it was a sign that your boost was entering the crankcase. Sometimes it would even leak around the oil filler cap.
Dzenno, if you have the BSH catch can, you should contact Phil @ BSH as he did a lot of work fortifying the VW PCV system and came out with some useful bolt on kits that made sure boost didn't enter the crank and that there was still a vacuum source during idle/deceleration cycles.