White smoke can also be from overfilled oil in engine. I had this problem also. brought car to dealer with 6 qts of oil (2qt left over and 4 qt new). They used up all 6 qts. I noticed on start up it smoked for a couple of seconds and then stopped. I drained about 1qt out and have not seen the smoke since.
Why is it white since it is oil? leaking through seals from what i've read.