Originally Posted by trader4

If it's a mayo problem, then the CCV system can be clogged, that is the essence of the problem, so I don't see the point there. The drain back to the oil sump is part of the system. I also don't see any evidence that a long drive is the solution to the problem. I agree short drives probably make it worse, but I don't agree that just taking it for an occasional long drive solves it. I see a lot of people having the oil separator problem, regardless of how the car is driven.

Also, it's another example of a screwy BMW design. This is the first engine that I've heard of where a CCV valve can cause all the sump oil to get sucked into the engine, causing hydrolock.