Musty smell from vents

[Brian3676]

Lately when I turn on my truck after more than a few ours of sitting or first thing in the morning the air smells super musty. Its only when the defrost is on (aka AC is on), and it goes away after a few minutes. Or I get used to it, not sure what one.

I replaced the cabin filter, removed the windshield trim between windshield and engine bay and made sure nothing was in there. Removed the motor/fan and it was spotless. Checked the drain and its 100% clear. When I had the fan out I got a mirror and looked at the ac coil, it looks clean from what I can see.

Anyone got any advice? Everything I read says change filter and check drain.

Thanks!

 

[4by4th]

An AC person once told me to always turn off the recirculation when turning off any vehicle so the system isn't closed and can air out to prevent that from occurring in the first place. Not sure if that will fix your issue or not but start doing it if you don't already. Also drive with the recirculation closed after you've flushed the air out of it to dry out any moisture inside. Somebody else (maybe same person, not sure, it was a long time ago) told me to always drive with recirculation on (humid Houston).

 

[JohnnyBrah]

i had the same thing. i used a can of lysol disinfectant spray (the aerosol ones that kill bacteria) and went to town on all the vents outside below the windshield/hood, with the engine on, fan on max, ac and heat on, recirculate off. i probably used about half a can but i guess the amount depends on how strong the odor is

 

[Brian3676]

I bought a can of the foaming stuff you put in the evap drain. Supposed to foam up and clean the coil. Not sure if it works or not, but my car smells like an awful perfume now. Hopefully it goes away soon. When it goes away, if the musty smell comes back ill try the lysol or something.

Thanks everyone