Skip the auto shop - Our mechanics make house calls

Q: Bad smell in AC vent

asked by on

I have a bad smell coming from the AC vent every time I turn on the AC. I have already changed the cabin filter and tried the Lysol method. Is there anything else I can do to get rid of this smell?

My car has 72000 miles.
My car has an automatic transmission.

Hi there. This is a concern I have had a lot of experience with. Has the AC drain grommet been updated or removed? The original grommet was designed with a small slit style opening and was found to not be sufficient in draining moisture from the evaporator. There would be a build up of mildew that prevented proper drainage thus resulting in Lexus authorizing the removal/replacement of those grommets under a limited bulletin.

If the grommet is not the issue, then moisture buildup inside the evaporator case is the issue. Toyota Motor Company released a tech tip to the dealerships that describes how to reduce the smell and I’ll give you the short version here: during the last 5 to 10 minutes of your drive set the climate control to max fan, fresh air, max cold, no AC, and leave the fresh air setting on when shutting off the vehicle.

This setting allows mass amounts of fresh air to dry the evaporator and case to the point where mold and mildew cannot thrive and leaving the fresh air setting on will allow the evaporator case to breathe and dry out. You may have to do this several times to help with the smell or an AC refresh service available at most service centers may be necessary if the smell is pretty substantial right now. Once the smell is gone, you may only need to do the tech tip once in a while as long as you make sure the fresh air setting is on when you turn off the vehicle. Your mechanic has several technicians available to inspect the air conditioner system and move forward with repairs.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. Bad smell in AC vent

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Transmission problems

Hello. The symptoms you are experiencing can be caused by a wide variety of issues. The first thing I would do is check to make sure that the transmission fluid is at the correct level and not dirty or contaminated....

Q: My 2008 Mercedes-Benz heater blows warm then cool air

The lack of heat being generated by your system may indicate a clogged heater core. The [heater core]((https://www.yourmechanic.com/services/heater-is-not-working-inspection) is a small radiator like unit that circulates the hot coolant from the engine through the heater core which then uses this...

Q: How do I fix load muffler noise from my Lexus RX 300

You will need to have the exhaust inspected to see where the exhaust is leaking. Sometimes the flex pipe connected to the engine goes bad and leaks. Other times the muffle can rust through causing this. Have a muffler shop...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...