I am fixing up my 89 740, 175k, w single overhead cam, 4 cyl engine - I notice oil spatter around the oil filler cap on the valve cover.
I replaced the flame trap, cleaned the throttle body, unplugged a clogged vacuum line, replaced some cracked vacuum tubing. I replaced the oil filler cap gasket, too.(the old one was like wood)
When the car is running and I unscrew the oil filler cap on the valve cover, it bounces around, and I can see visible blow by. It does not get sucked down by any vacuum.
Is this normal? I have heard that this was a way of testing the PCV system for some models, not all.
Car is running very smooth, plenty of power. Do I leave well enough alone?