Stop The (AC) Stink


At one time or another you've probably noticed there's an odor, and not a pleasant one, coming from your air conditioning and heating vents.  What you're smelling is, in all probability, mold, or at least wet dirt.  Yes, yuck! It's more common than you might think with hundreds of comments on various automotive forums about the AC stench and how to get rid of it.  There are a couple of things I'm aware of you can try.  The first, the cabin air filter, is a normal maintenance item you're 'supposed' to do every year.  The second involves filling your system with chemicals that are supposed to wipe out stinky spores, eradicating them from your system.   So, let's rid your cabin of those noxious odors, maybe permanently.

What You'll Need

1. A fresh cabin air filter.
  Unless you've replaced yours in the past year it's (depending on your local conditions) probably full of fine silty dust, pollen or other grunge.  You can visit your Toyota dealer for a replacement or shop online.  I'd recommend one with activated charcoal in it.  This Cleenaire CAF10285A is the filter I'm using.  It might be all you need!Kool_it

2. When your system smells really foul
a chemical cleaner is the next logical step. These range from squirting a little Febreze into the fresh air intake at the base of the windshield to a full on AC cleanser that flushes all the poisonous plant life and bacteria from the system. I use a product called Kool-It  which works well and, for awhile anyway, leaves a bit of lemony scent in the cabin.  There are many other products that do the same thing so that choice is, as it should be, up to you.

How To Do It

1. Change the filter.
Toyota's engineers made this really simple for Avalon owners.  You don't even have to remove the glove box door.  Just pull all the detrius you've collected in there over the past months/years and put it on the floor for sorting later.  Reach in and pull the latch over and remove the air filter door.  Now you can see the filter.  Pull it toward you noting the ^^^^ arrows showing airflow.  Slide in the new filter (arrows pointing down), close the cover, put your 'now well organized' stuff back in the glove box and you're done.  Ten minutes or less well spent.

2. Grab your chemical solution.  Read the package directions carefully.  Some just require you to spray a solution dowDrainn into the fresh air intake while the system fan is running.  If you choose a Kool-It type solution you'll be jacking up the right side of the car a few inches to gain easy access to the AC drain tube.  Check out the photo at right.  The tube is on the right side of the car just outboard of the catalytic converter.

Insert the long tube from your chemical container into that drain hose as far as it'll go and start the chemical (foam) flow.  When the can is empty remove the tube.  At this point I diverge a little from the instructions. I use a stopper (cap of a marker pen works great) in the drain hose just so the liquid has a little better chance to work.  After a few minutes, remove the plug to let the liquid drain and resume following the instructions.  That normally involves running your AC fan for a length of time.  Be sure the system is set for "fresh (outside) air."

3. Problem solved!  But wait, there's more!  You want to prevent this from happening in the future, right?  Here's the most often recommended way to do that besides replacing the cabin filter annually.  Rather than leaving your system in "Auto" which often chooses to recycle the air rather than bring fresh air into the cabin, hit the button to toggle that setting to outside air at least for a few minutes before shutting the car down.  Unless it's raining, that should help dry the system preventing mold from forming.  It should also keep the fresh air flap open so moisture can evaporate rather than staying trapped inside that dark moist box.

4. Done! Beer