Quote:
Originally Posted by Zaaa
I will restate the fact that while I had the BSH OCC installed I was experiencing a rough, lumpy, unhappy sounding idle. Since I've taken it out and put the stock tube back in, everything is smooth and happy. Coincidence? Maybe. But I don't think so. For now I will just be accepting blow-by until someone comes up with a proper solution  |
this has nothing to do with a OCC... only used under boost
Quote:
Originally Posted by Big Tom
You will get vaccum from the crankcase regardless if the checkvalve is there or not.
My theory is that this checkvalve is there to prevent the boost spike coming from the DV's.
...and I'm using BOV's so I will not be affected by this issue.  |
The vacuum is not from the cc, but other side of the pcv system inside the cylinder head cover (off boost)
Quote:
Originally Posted by RobBeck
That Big Tom catch can appears to be the fire!! Good job!! (I want one!!)
But, you need to get that check valve back in there. Its needed as when the intake manifold (post throttle body blade) is lower vacuum than pre-throttle blade... The secondary check valve opens and that one is supposed to close. So in essence you are creating some sort of vacuum leak at idle and ver low loads without that check valve in place. Aside for that, looks amazing.
As for the secondary check valve, it's supposed to close when the post TB blade pressure is higher than the pre-TB blade pressures (ie. Under boost and mild engine loads). At this point the check valve you ommited is to open and is essentially what you have in your setup.
Can anyone locate this secondary valve? It's in the diagrams but I havent had a moment to tear my car down to find it. I have concerns it may need replacement after time, and if it leaks under boost it will cause the turbos to pressurize the crankcase.
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this check valve is inside the cylinder head cover i believe. It is possible that the on boost side could have 2 check valves, one inside the valve cover to close the boosted pcv side and one for DVs like Big Tom mentioned. I remember the BMW pdfs showing both check valves inside the head cover.
EDIT: see Dzenno's post