recently purchased a 2005 rover. I am experiencing tremendous vacuum in the crankcase. On the trip back to Michigan from Az. it went thru 15 quarts of oil. I stopped at a dealership in Tulsa and they changed the oil seperator and I went on my way. It didn't fix the problem and I went back to get the system checked again. They seemingly thought they fixed problem and again I was on my way. The problem still exists. It even makes a whirling noise when vacuum increases. Noise will quit when I take off the oil filler cap. Any ideas?