Strange Smell coming from the AC Vents

Hello All,

I am getting a foul smell coming from my air vents when I disengage the AC and have my vent on recirculation with the temperature on low. I had this issue since I had 2000 miles on the truck. Any ideas? It seems like something is molding up.

 

Pull your cabin air filter out and see if it's wet or anything.

Odd for a new truck unless somehow water is getting into the vent system from the cabin air intake.

 

Great advice. I will check it out.

 

Lol, reminds me of a story about a mechanic who get really pissed at a customer once and shoved fish pieces down the defroster vents.........did you piss off your mechanic lately ?....lol

 

When you turn off the ac but still keep the thing flowing air?

I'm every car I've ever been in they all have weird smells when that happens. New or old.

Maybe I'll try it tomorrow in my Tacoma. I haven't tried yet in this one.

 

Condensation drain line plugged?

 

I am my mechanic. Yes, I pissed myself off, but I skipped the fish.

 

It will be interesting to see what you find. I had over 20 cars in my life. This is a new one for me. Of course, I normally replace my filters.

 

Interesting. Those cars I mentioned never changed those filters. But the again I had a 2015 BRZ with 5k or so and I'm pretty sure it had that really weird smell when turning off the ac like that. Maybe like a dirty swap cooler or something.

Oh...have you ever been in a car in the summer where you've used the ac, gone into a store, then started the car and the blower was on but not the ac. It blows out some smelly humid air. Is it like that?


I'll try tomorrow and see. My truck has 6k. It's pretty cold here but I'll give it a shot.

 

The best I can say is it smells like a moldy heat exchanger. I just never expected that on a 3 month old Toyota.

 

A little mud can plug up the drain line.

 

Makes sense, but I have not been off roading since I bought the truck.

 

Don't have to off road to get it. Spray up from the road.

 

Oh, you know the puddle of water when you park to go in the store and come out to see it on the ground?
Thats the drain line working.

 

Good point. I will have to check for the drip.

 

I've had to replace my cabin filter after my most recent trail ride. Anytime I turned on the AC, we were tasting dust. I will say the oem filter feels flimsy so I would check out your options in the aftermarket world before spending money on a factory part.

The factory drains can get clogged (how quick depends on where you park everyday) but typically your floorboard becomes wet if the AC drains are clogged.

 

This sounds stupid, and just as I thought, this is super common.

I googled this exact quote "ac smell when turning off" and found a ton of threads on different cars with this type of issue. One of the vw ones had some "solutions" to fix it. Even popped on new cars.

I always thought that was just a common thing with ac and never thought twice about it.

 

I am thinking stinky heat exchanger fins.

 

I have had the drain plugged, sprayed smelly mist, but no water on floor. Maybe I fixed it sooner than that.

 

Weird for a truck that new.
Thoughts:

• Clogged drain hose- crawl underneath and unclog with thin stiff wire

• Moldy evaporator- BG Frigi Clean will help... Google it to see how to clean the evaporator. Also here is a link to IH8Mud with a write up: https://forum.ih8mud.com/threads/cleaning-ac-system-and-evaporator.92253/

Note: Drive with the AC on fresh if you can.... at a minimum when you are about to shut the truck off, switch the ac to fresh.... Recirculate allows moisture to remain on the fins of the evaporator and that causes mold over time.

Good luck!