Bad smell in my face

Hi Guys,

I enjoy your show and newspaper column. Here’s my situation. I have a 2008 Grand Prix with a stinky problem. There’s a terrible musty, moldy smell that comes out of my vents(any vents, i.e. dashboard, floor, defrost) after I shut off my air conditioning. When just the fresh air from outside is coming through the vents, everything is just fine. When I turn on my air conditioning, everything is just fine. When I turn off my air conditioning is when the funky smell starts.
Mechanic number one cleaned out the drain hole, sprayed anti-mold spray and foam through the air intake vents with the recirculation switch on and the windows rolled up. But the mold is still there. Mechanic number two shared with me that the only way to get the mold out is to disassemble part of the A/C unit, physically clean out and disinfect the unit and then add some other part that helps drain or dry the unit so moisture never sits in there and starts the molding process. Is that the best way to deal with this problem? Mechanic number two said to do this would cost between $300-400. I can’t stand the mold smell in my face and am willing to pay the money because there is only 50,000 miles on the car and I plan on keeping it for several more years. My question is will that procedure solve the problem for the short and long term?

Thanks, guys.


there is a plug on the cover of your AC unit on the firewall and its clogged. There is a rubber spout on the bottom take something and poke up in the hole to clear it out. It may take a long time for the smell to clear out it all depends on how long it has been clogged and how much mildew has grown. You also might spray some mildew remover in it.

@JoeJoe I realize that Pontiac no longer exists . . .

I feel you should go to a Chevy dealer and ask them to activate the after blow function of your HVAC control module. If your car does have that capability, they’ll be enable it with their factory scan tool.

@knfenimore I just watched that video

What that guy is doing is fixing the symptom, not the root cause.

That is what the afterblow function is for. In fact, there are afterblow modules that can be connected to cars that didn’t originally have that function.