I have a 240 D with high oil usage that diminishes with the oil level (as splash lube decreases, crank air dries out). Lack of an obvious leak on the valve cover or head gasket, and the uniform coating of oil under the hood make it look like blow by but I got some conflicting information.
Ring blow by seems negligible based on the valve cover breather test per:
An oily blows out of the breather tube.
Crankcase vacuum as measured at the oil filler tube was 10-20 mm Hg at about 1/2 throttle- hard to tell as it was as full scale is 760 mm Hg.
Manifold vacuum was 60-80 mm Hg at about 1/2 throttle.
So I'm confused, I thought I'd find high manifold vacuum drawing excessive air through the crankcase or something. Do I just need to replace the breather? And if so, where do I find one, tried autozone and autohausaz, no luv.
What does this information say about the health of the engine as well.
Thanks,
Andy