Thanks!

The 530i has 195K and the ZHP is at 90K now. My personal feeling was that 800 mi/qt was pretty crazy consumption, but both BMW and my indie mech at the time said that was on the high side of acceptable. I didn't really question it until it got significantly worse - which led me to some discoveries about how the CCV worked and ultimately led to the more typical PCV-managed crankcase breather.

I've written some opinions on the subject of the M54 CCV on other forums. The CCV not only acts as an oil separator and return, but regulates the pressure in the crankcase by closing off and releasing the breather. I think there are conditions where the CCV causes momentary positive pressure in the crankcase, which results in oil siphoning from the pan through to the intake manifold, as well as contributing to the short lifespan of valve cover and oil filter housing gaskets.

I'm very happy with both cars at 2000-2500 mi/qt now, and suspect that is close to the average. I really don't think there are too many engines with no oil consumption. With an OCI of 7500 mi, which I think most of us do, we could be 1.5 qt down at oil change and not know (without measuring) what comes out.

Quote Originally Posted by KevinC View Post
Welcome!

What's with the crazy oil consumption? Are both cars hyper-milers? I'm at 80k and have never burned a drop. But 80k isn't much I suppose.