Any clue what could be causing this? If I run my fan and have it set to take in air from outside the car (without the A/C on). I get white smoke coming out of all 4 of my vents - a lot out of the center 2 and then some on the driver and passenger one. I've had a musty smell if I just run the blower (on cold) and no A/C. But then if I set it to recirculate the cabin air the smoke goes away.

I swung by my mechanic and he tried to sniff it and see what it is but he's not completely sure. I have an appointment Friday to get that looked at and have my A/C recharged, but does anyone have any ideas on what's causing the smoke.

Thanks,
Mike

EDIT: Also, I had a couple leaks about a month ago. One was my drain was plugged and my passenger floor turned into a swimming pool. Secondly, I had an issue with the cowl screen (I think that's the term...the black plastic piece under the wipers). But it was right by where the cabin air filter is and at the time I didn't have a CAF and water went through it and came in by the heater core. So could the leaks have messed up my heater core and that's my problem?

 

First, if you were (and possibly still are) getting wet floors, I stand by this repair (cheap, easy and takes about 5 minutes):
https://montecarloforum.com/forum/si...lem-fix-26663/
I was going to do this as preventative maintenance, had the piece and low and behold, turns out good I got the piece, as my carpet was beginning to get wet (found that the original idea GM had fell off).

As for the smoke, you mention only when using outside air. I'd check the cabin air filter. See if it's plugged, if something got into it, if it's soaked.....
Does the smoke have a smell (like anti-freeze or exhaust)? When I put a Daytona Hood (which has a raised cowl), I found the hard way I had an exhaust leak at the manifold (the car has a carb on it, if I turned on anything with the HVAC immediately after starting the car was worse then waiting a few minutes, one time I got so much exhaust in, I pulled the car right back in the driveway and grabbed another car to take to work). Never had the issue until I had the raised cowl, but I made sure to fix this ASAP once I found the problem (about a week of having this issue).

 

The leaks have been fixed already, and after investigation I found I had some crap in my air intake. I removed it...no smoke, no more musty smell.

 

Sounds good. If I might offer a suggestion, if you found crap in the air intake (I assume in or near the cabin air filter), this might just be a good time to replace the cabin air filter. I replaced mine for about about $7 when I was ordering other stuff from RockAuto. I'm sure you can nab it locally for $10 or less.

 

The 'smoke' may have been residue in the ducts from the previous leak. My old Blazer did that after replacing the heater core in it. I ran the heater on high for 10 minutes in each duct position and it stopped 'smoking' after that.