Vapor coming from air conditioning vents!
 

My 98 A4 has started spewing visible vapor (it looked at first like smoke and frightened me!) from the a/c vents, accompanied by an unpleasant odor. I searched the archives and found a few references to evaporator drain clogs, but could find no details on whether there is a DIY fix and, if so, how to do it. Could anyone shed some light?

Howard

Normal.
 

The air is simply condensing. It's normal during days of high humidity, where the cold air, contacts water in the air, and cools it down enough to condense out of vapor, into liquid.
It's the same phenomenon that causes your Pepsi can to condensate on the outside of the can, when it's humid outside.

is it the same for coke cans too? : ) j/k

In old VW's it was often a propylene gylcol leak that produced similar results...
 

not harmless. But of course this is a new car so it's probably not that...it usually also had a white tint almost powdery...
ajp

Coolant usually has a very sweet smell to it.
 

On VW's, the problem usually was a leaking heater core, that actually leaked coolant into the passenger footwell area.

Doubt it, Coke is inferior in its design. :)

yup - happened in my old Vanagon...Although I'd call it a sweet stench...not pleasant in my op.

this should be in the faq .. whatcha' think sal?

Re: this should be in the faq .. whatcha' think sal?
 

Really? Where's the FAQ?

If it smells like rotten tuna, it could be the evaporator core.