Now I am having another problem with my 2004 x5 with 95,893 miles . It appears to be smoking from the tail pipes blue smoke. One of my mechanics said it appears that it's burning oil and may need the valve seals replace. Another mechanic look at it and stated that he does not believe it's the seals. He stated that it may be an emission problem or maybe a sensor or something. Note; no check engine light and the vehicle was sitting a while before I brought it. I took it to dealer and no problem with engine was noted. Car runs well and fast with no knocking. I changed oil seven months ago at the dealer and had to add 4 quarts of synthetic oil this month although the car was not driven since the oil change in February until this August. Please help if you have any information.