i've been reading lots of threads here and haven't quite narrowed it down yet. i have a 1996 850 turbo with 117k. it smokes pretty bad on start up, white-ish blue i guess and water. also smokes if left at idle for a few minutes. the entire rear of the car also has some oily substance on it. has been doing this for a while now, but recently started using alot of oil, emitting burning oil smell, and a little foam on dipstick. also, the oil reeks of gas and mileage has dropped. it looks as though oil is burning in the catalytic converter. even with all this the car still starts and runs fine. if it didn't smoke or smell you couldn't tell anything is wrong. valve guides? this is my first posting on the board, please help!! thanks, in advance!!!

also, no warning lights are coming on.