Hi everyone- new to the forums; and here because I thought you might be able to help. I have a 2002 Passat GLX wagon (58k miles) that has always run fairly well, barring a transmission computer reprogramming a ways back. About 2 weeks ago the check engine light came on solid, and stayed on. Checking the oil before a big trip I noticed it was down and added about half a quart to get it back to proper levels. Poof- Check engine light off. Now today, the car has started running rough and knocky and producing a huge amount of white vapor exhaust (no particular gas or oil smell)- and the check engine light was blinking. It seems to settle itself down in a manner that would suggest to me (in my limited experience) that it's not a mechanical failure, rather a computer control issue. Thoughts?? Thanks in advance-

Check the codes (it's free at autozone or buy OBDII scanner). White smoke usually means water, which comes into probably turbo. Oil needed to be used is fully synthetic because of higher breakdown temperature about 400 degrees as oppose to regular 250 degrees. From previous threads it looks like your turbo is going bad--sorry to tell you. Also, run engine for 1-5 min before shutting it down-it will prolong life of turbo.