: Foul Smelling Air

10-16-07, 03:58 PM
My 05 STS has a "sour" smell, I guess you could call it, coming out of the air vents when I turn the air conditioner off. It only happens when the fan is blowing without the air conditioning button pressed, and it's only when the temperature is turned down. When I turn the temperature up, the smell goes away.

Any ideas on what it may be, or how to clean the vents to rid the smell?

10-16-07, 07:25 PM
2 Things I would do, check your cabin filter, and make sure the AC drip tube is clear. The cabin filter is on the firewall under the hood, the drip tube, I would have to hunt for that. Oh and maybe spray some Lysol in the hole with fan running full power before you put the cabin filter back in. My new cabin filter did not fit that great, but I got it to work.

10-16-07, 08:33 PM
how many miles on your '05?

can you describe the smell in further detail?

any friends or kids barf in the back lately?

vacuum under the seats? etc. trunk leaking? Lots of possibilities here.

Don't mean to be a smart a** but... is the smell chemical in nature or organic?

Cabin filter, a/c out of the question... lots of options here. Coolant smells sweet, refridgerant..chemical etc.

10-17-07, 01:08 PM
There may be standing water in the drainpan of the evaporator ( a/c ) coil , that may have mould growing in it.
Your dealer may have a chemical that can be sprayed into the air intake to kill it .
Standing water alone can smell pretty bad over a period of time. My 2000 sts used to turn the heater on for about a minute when i had the a/c off to overcome any standing water , but it used to overheat the cabin.
The on time was adjustable , and i had it reduced but it still got to hot in the car.
Warm air will evaporate any moisture on the a/c coil and make the smell go away.