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Old 04-21-2011, 08:29 PM
Got_boost? Got_boost? is offline
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Location: Seattle
Join Date: Apr 2011
Posts: 5
Mein Auto: 2004 BMW 745li
Originally Posted by Keif View Post
The state of the CCVs shouldn't impact secondary air flow, only crankcase pressure, intake pressure, and oil/air separation. The secondary air pump pushes fresh air directly into the exhaust manifold / post-combustion area in the head to continue burn during cold start (to improve emissions, I believe) -- so that system is entirely independent of stuff related to the CCVs ( help you eliminate items).

You replaced both the hose and check valve and still had the issue? Have you pulled off the connector for that hose at the front of the engine and tested the air pump that way? I think a while back someone ran power straight to the pump to test it (look through some threads about the air pump); I can look up the wiring diagram if you need it. Just because the pump is buzzing doesn't necessarily mean it's actually pumping anything, and maybe the bank 2 side check valve just isn't as stiff or something (i.e. easier to push air through and so is not faulting).
I will unplug the connector and test the pump tmrw. I have not tried that. I had someone replace the passenger side valve cover. So i was wondering if they put the wrong one on, because there should be that pressure regulating vavle right next to the oil cap,(as you can see in the pic from real oem) but my car doesnt have one (as you can see in the pics up there). So im just trying to see if other 2004 bmw 745li's have that, or if it looks like mine, because i would think without that pressure regulating valve, it is unable to regulate ccv pressure in the head on the left(passenger side)?
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