Sale
BMW has an issue with oil separators freezing in cold weather if the engine is not fully warmed up during driving. Common symptoms are a howling noise followed by oil leaks.
Crankcase breather valve used to purge the oil vapor from the engine block into the valve cover. This valve has 4 hoses connected to it, running to the dipstick, valve cover, and air intake.
Bavarian Autosport
