babaijebu

I have changed the air filter and that didn't help. What helped for a while was blasting hot air for a while (hell to do since i live in Texas). The smell was coming back again and i just had to blast hot air on my way to work yesterday and didn't smell it on my way back home. Would an AC flush help with this? can't be blowing hot air when it's already over 90s outside.

HOMER350

Did you try an AC Vent Duct spray? It's been working for me for years. Nothing fancy just the can auto parts store.

Would be nice to rule out that you don't have a more deep rooted issue.

After spraying, follow techniques to prevent it from reoccurring.

babaijebu

I will give that a try.

HOMER350

I think this is the one I've been using. Unsure because the changed the style but I'm almost positive. Suggesting it because it has a really good scent..kind of a new car scent. But it does not only mask the musty scent...it works.

Amazon

JNP1227

iTrader: (1)

I also have this issue. Dealer has changed the cabin air filter and did a full clean of the HVAC system:

- DISINFECT AND CLEAN YOUR VEHICLE'S HVAC SYSTEM
- SPRAY BACTERIAL DISINFECTANT INTO THE VEHICLE EVAPORATOR
- DISINFECT VEHICLE'S COMPLETE VENTILATION SYSTEM

Smell still came back after few days. Going back to dealer for them to do the cleaning again. I do remember recently I had to get my Freon refilled due to it being low which means there is a leak somewhere.

Would a leak cause this mildew/vinegar smell?

logix1229

It’s because Lexus does this stupid annoying thing where when you turn on the AC, the car automatically switches into recirculate mode. I’m almost certain 99% of people don’t even pay attention to that and just let the ac run without thinking to change the mode from outside air to recirculate, etc. since you’re getting the cold air and you blissfully drift off into a state of coolness...haha.

(probably isn’t the real reason it’s causing the musty odor but just venting about that little annoyance. Lol)

my only tip tip to you is when you turn on the AC, hold down the “outside air” button while pushing the AC button, this will keep it from going into recirculate mode automatically and then after a few minutes or whenever u can change it to recirculate. That’s what I’ve done and it’s worked fine. And I replaced the cabin air filter.

AtomicAWD

Thanks, I put in a K&N but it's always musty with AC off. Will try those things.

babaijebu

So far, so good after using a spray this weekend. I sprayed half while on full blast AC and other half on heat for about 7 mins each. I will probably do this every month from now on.

14ISWhtF

So my 2014 is250 is also having this issue. Since the evaporator is what causes condensation to form around it, could it be the drainage tube that might be clogged up and the buildup and moisture collecting causing bacteria to form and create that smell? The disinfectant on the evaporator is a good solution but wouldnt a clog also be another spot to make sure as well?

macmaster

Every Toyota/Lexus I've owned has this smell after turning the AC off. I never thought there was an issue.

FNMUPN8

This is the cause. Super cold air in the vent system cools the plastics. Then the car heats up quickly after you shut it off. The temperature difference promotes condensation. The condensation accumulates at the bottom of the system due to gravity. There it stays warm between start ups and mold loves warm moisture. Had the issue with every Toyota, Lexus I've owned. When the AC starts up again the smell goes away, but you are essentially blowing mold about your cabin. Had a bad issue with this in a Camry I owned. Constant runny nose and sore throats until a Dr told me this and an honest Toyota service tech explained and confirmed.

andy350

Check under your rear floor mats and under your drivers seat…see if it’s wet.
that wet carpet can smell like mildew
if it’s wet, your a/c drainage pipe is clogged up.

RDix

I was told the position of the AC evap box and the fact Lexus recirculates air upon start up causes this issue if the AC is not to fresh air prior to turning off the motor. Even with doing that I still have mold smell. Car was used prior to purchase and I believe the airbox molded. It's been cleaned by Lexus 3x and I was told this is considered "regular maintenance" - never had to do this on my '06 GS so I'm disappointed.

ANyone know where the AC drain is located under the car? My mechanic said it looks to be dripping on transmission and wonders if its above the transmission. I would like to do a few cleanings a year myself ($10) vs Lexus for $189

Kb2017is

I would also like to know where this evaporator drain line is located.