For years, my wife's E53 X5 asked for oil (low oil message on the dash) every 1-2 months. Today she commented that it hasn't asked for oil in quite awhile. I pull the dipstick and it's bone-dry. When I took off the oil cap, I see the dreaded yellow sludge is back with a vengeance.




We had this issue a few years ago. In 2011, we had the oil separator/CCV replaced and the problem went away. Now it's back. I added a quart of oil and it barely reached the tip of the dipstick, so I think the oil-level sensor might be kaput too. What's the normal dipstick level where the low-oil message should be issued?

Is it possible the sludge has accumulated on the oil-level sensor? Why does the CCV suck so much on this vehicle?

My wife's commute is 35 minutes each way - half highway, half city.

Advice?