I have 2007 X3 with N52 engine, bought it used, CPO with 38k on it, now approaching 102k and it runs great. One issue that I am struggling with is oil consumption.
Oil consumption has been an issue with this car since day one. Right after oil change, it is consuming roughly 1/4 of quart every 1000k miles. But as oil get older (3k after oil change), consumption increases and rate is 300-500 miles for every notch drop (.25 of a quart).
Have complained several times to my SA and each time he looked at it, and PVC, and oil cooler gaskets were not leaking.
CPO warranty expired in December, so on the last day I called and asked to have it checked again just to be certain. Several days back I get a call saying that nothing was discovered. They performed several tests, visual inspection and everything looks good. Then he said, we can do compression and leak down test and if nothing is discovered, I will be charged for these tests ($500). I authorize them to proceed, thinking that if something is discovered, then it will be fixed, and if everything comes back normal at least I have some peace of mind..
Well, nothing was discovered. The exact reading for compression was 231-232 psi across all cylinders. Leakdown was 11-14%, cylinder #6 being worst. SA stated that anything udner 20% is acceptable. Is that correct?
Also, can anyone please help me understand why oil consumption is increased? This pattern is observed with Mobil 1 High Mileage FS, Castrol FS, and BMW oil. I performed extra oil change between dealer changes at 7500 miles using one of the oils listed above.
My old 330i had 130k miles on it when it was sold and oil consumption was 1/2 quart between oil changes (7500 miles). Consumption did not increase, granted, 330 was driven very differntly than X3 (not dogged, just opend up almost daily). I am really puzzled here to what is causing this.
After I paid my dealer for these tests, I called BMW NA to try to get money back, they basically said take a long walk, you agreed to pay for it, so it is between you and your dealer.. Figured I would try..
Sorry for long post!