I just had this oil separator issue as well and BMW said they would not even cover the parts on my 01 X5 4.4i. May end up costing me over $2,000. If I could turn back time, I would have sold my BMW when I had 80,000 and still had 20,000 on the extended warranty. My tranny went out at 102,000 and BMW (gracious as they are - not) gave me 50% off on the parts. How nice, eh? I think I'll stay with the Germans next time, but give my money to Audi.