Honda Civic 2009 AC smell

Hi, I need some help to self-diagnose with my Honda Civic 2009 AC’s problem before I have to go to the mechanics. The air comes out of my AC smells like piss/sweat when I first turn my car on and goes away after a couple minutes, and the smell won’t come back until I let the car rest for a while and turn it back on.

I tried to look at the air filter and it doesn’t have any of that smell, so I am at lost. Anyone can offer their insight?

Thank you

If I were to get this car?

I would put on a dust mask, latex gloves, safety goggles, remove the blower motor, and feel what is found.


Could be mildew/mold/funk on the evaporator core. To prevent this, turn the AC off, but leave the fan on for a bit before shutting off the vehicle. This will dry out the evaporator and prevent the mildew from accumulating, or so I’m told.

In the meantime, you might try spraying some Lysol into the HVAC intake on the cowl with the AC running full blast to kill the bacteria and reduce the smell.

Good ideas above. While doing that, ask the shop to also make sure to blow some compressed air through the AC drain hole to make sure it is clear. Running the AC on “fresh” rather than “recirculate” might help too. And pull up the front carpet a little to make sure the floorboards are completely dry.