In my own situations there have been two causes of white smoke. First is the white regen smoke when the exhaust system is not up to temp. Usually burns off after a mile or less. I watch all the regens on a livewire, and every time, there is at least SOME white smoke when it starts. Usually very little in hotter weather.
The other situation (only happened to me once but heard others complain of it on another forum) involves the air filter and it possibly becoming saturated with water (and/or possibly a sensor or something intake related). In a very heavy rain storm, I had driven for about an hour at a steady 50mph in torrential rain and very saturated roads. I had to slow down to go around a ramp to get onto the next road... and upon acceleration, the power was just NOT there. Looking back in my rear view, I was fogging the road with heavy white smoke and it was NOT in regen (according to the livewire). Lifting off of the pedal and getting back on seemed to help it. It ran like it wanted to keep doing that on heavy accel (50% or more throttle), for the rest of the day. The next day, after the monsoon was done, it was fine. Has never done it since.
Not sure if that helps you try to determine what is going on, but just figured I'd share.
Last edited by ZeroOne : 06-23-2008 at 08:38 PM.