would a dirty cabin filter be the reason to a smelly AC? because when i turn my AC on it smells really bad

does anyone smoke in your car? I could always tell a rental with a smoker...it's like blowing cold ashtray in your face. Blegh.

This is a very good question!

Actually the smell from the A/C is due to mold/mildew on the A/C evaporator coil.

When the A/C is running, water vapor from the air condenses on the much colder evaporator coil (the 'cooling' coil portion of the A/C located inside the car). Dust, dirt, and mold spores can collect on the damp evaporator coil and mold/mildew can form. This is the source of the 'musty smell' that many complain about.

Solution: Have the coil professionally cleaned. They will spray it with a disinfecting cleaner that will kill the mold.

Prevention: Turn off the A/C and turn the fan on HIGH speed about 5 minutes before you arrive at your destination. This will evaporate any accumulated water on the coil and prevent mold from forming. Mold loves dark and damp places.

wow mold, haha thanks ill get this done soon

philipa_240sx wrote:This is a very good question!

Actually the smell from the A/C is due to mold/mildew on the A/C evaporator coil.

When the A/C is running, water vapor from the air condenses on the much colder evaporator coil (the 'cooling' coil portion of the A/C located inside the car). Dust, dirt, and mold spores can collect on the damp evaporator coil and mold/mildew can form. This is the source of the 'musty smell' that many complain about.

Yep I was going to offer a similar suggestion. Our previous car (Acura) developed a bad smell from the AC when it was less than a year old. In our case the dealer determined the drain hose from the evaporator was kinked or plugged and the water couldn't drain properly thus allowing mold to form.

To test... they had me run the AC on a warm day for about 15 minutes. Then had me shut the car off wait about 5 minutes to see if a puddle of water accumulated under the car (to verify the evaporator drain was draining properly). Nope! No puddle.

I'm not sure if the smell went away once they fixed the drain or if it was because they also cleaned the coil. (makes sense) They just told me the problem was with the drain. Anyway the smell went away and everything was fine.

On my Rogue (I checked the drain the first time I fired up the AC) it drains left of center just under the area of the passenger seat. Nice big puddles.

BTW... Great tip on turning off the AC and running the fan on high for 5 minutes to dry the coil. It will become part of my regime.

philipa_240sx wrote:Prevention: Turn off the A/C and turn the fan on HIGH speed about 5 minutes before you arrive at your destination. This will evaporate any accumulated water on the coil and prevent mold from forming. Mold loves dark and damp places.

I've done this on all the cars that I have owned but I only turn the fan on for 2=3 minutes and only on medium speed. I guess Philipa's suggestion is better to ensure evaporation of accumulated water.