Smoking Vents?

[Philossifer]

Originally Posted by Rosco

Ok, im not sure exactly what is happening. It started yesterday, when i turned my car off i would get some moisture on the inside of my windshield above the vents. Well now I just got home from work, and the moisture started to appear again, but now there was white smoke coming from the vents for about 25 seconds. Any ideas?

Rosco,
If your heater core is leaking, the smell of antifreeze will be very strong and your windows will fog up quite a bit and stay fogged.

The white smoke coming from the vents might be ice cold water vapor when operating your A/C. It's fairly normal in humid climates but in your case, it might be that the evaporator drain is either clogged or partially clogged. The condensation from the evaporator doesn't drain, and gets blown through the vents as cold vapor (when the A/C is on) which is the white smoke you are seeing.

Another possibility is that your A/C is slightly undercharged which would cause the evaporator to freeze up. This would cause the white vapor too. But, eventually, if you drive the car long enough with the A/C on, there would be so much ice built up on the evaporator that it would block the air flow. You could tell if that were the case when you get little or no airflow, even with the fan on high. Then, if you turn the A/C off, as the ice on the evaporator melts, the airflow would slowly return to normal.

My guess is that your evaporator drain is clogged. From under the car on the passenger side, find the drain and run a wire coat hanger through it to unclog it.
Good luck,
Phil