Musty Smell when A/C turned on - Help!


550rwhp

GT Owner
Nov 6, 2012
199
North of Dallas, Texas
Hello Forum.

I have been experiencing a musty smell when the A/C is first turned on, the smell goes away after a minute or two. Form past posts, I see others have experienced this too.

What is the cause? What is the fix? Do we have cabin air filters? If I were to spray a deodorizer where would I spray it? Could this be a A/C condenser draining issue?

Thank you to all that respond with solutions or comments.

Jack
 
I get it on my Vette not GT

I hear a distinct "flap shut" in ducts sound when I turn A/C on in GT

I always Turn a/c OFF before turning car off...and this i believe leaves ducts "open" and allows air to dry out ducts
 
How often do you run the a/c?
 
I run the a/c every time I drive. So, once a week. I did just buy it and think it was sitting for a while.
 
I've notitced that too occaisionally, figured I got water in the inlet on the hood. Will have to be sure to turn a/c off before washing.
 
We went for a ride this summer and when I got home there was water dripping down the floor mat on the passenger side.
 
We went for a ride this summer and when I got home there was water dripping down the floor mat on the passenger side.

Condensation or left over from washing?
 
If you look under the car, on the passenger side, at the back of the tire,there is a drain hose from the HVAC. Make sure it is hanging down and not blocked. Easier to do when up on lift.
 
Condensation or left over from washing?

Condensation....
 
You probably cant see a tube. On my car, the tube just dumped the condensation into the front pan. I extended the tube to get the condensation to the ground with plastic tube. I got the idea from an OLD thread on this topic.

If you look under the car, on the passenger side, at the back of the tire,there is a drain hose from the HVAC. Make sure it is hanging down and not blocked. Easier to do when up on lift.
 
This is a common problem on current vehicles that are not driven much. There is probably some mold or such growing in the system from condensation. I doubt it happens in dry climates.

I good circulation of lysol or bleach aerosol product through the Ac recirculation vent should take care of it. I dont breath or that stuff gags me!!!


I try to turn off the ac compressor and run the fan with outside temp air for 15 minutes or so before storage to dry out any standing moisture in the system, it seems to work for my GT and my T-Bird.
 
Excellent. Thanks for all the feedback.

So there is no cabin air filter?

What is the purpose of the center duct near the windscreen? If that where I spray the lysol or cleaner?

This forum is excellent and full of helpful owners.
 
There is also a section on human odors that I didn't copy. "Human odors may be eliminated by removing the source and cleaning the affected area." bahahaha!

The center duct is the cabin fresh air intake. No cabin air filter.

ac_0001.jpg

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PERFECT!!!

Thank you
 
Spray a healthy dose of Lysol directly into the cabin air intake.
 
I had the same thing with several cars. Here's what you do: Run the air conditioning with the temperature all the way up on heat for about 30 minutes and bake off all that gross stuff causing the odor. You might have to do it a couple times. Once you get rid of the odor, get into the habit of turning your air conditioner off while still circulating the vent for a couple minutes to get all of the cold air out of the compressor before you turn the car off. If you do this, the smell wont return.