garygve

I wonder if they changed the plenum design since 2007 and maybe its not allowing all the condensation to drain out when the vehicle is parked causing the smell. The fact that the service rep knew about this tells me Lexus knows they have a design problem but aren't going to do anything about it since its not a major flaw.
When you pay for a premium SUV that has been made as long as the RX there shouldn't be problems like this.

m1964

I agree- I got the same smell in my 2012, which is in service right now- Toyota has a "desinfecting kit" ($ 20) but yoiu have to get under the RX to use it.

The problem started this summer, I bought it in Feb 2012.

niklow

I have exact same smell in my 2015 f sport. 5k miles on it.

Lexus, says its in my head. but i do turn the ac off before parking. the smell does come back when starting up a car in the morning or when leaving it for a while.

Rillo

Sometimes this happens when mildew forms in the system. To cure it yourself spray disinfectant spray like Dettox into the air vents on the scuttle at the bottom of the windscreen near the wiper arms and run the system on full fan hot and cold for 5 minutes. Fixed it for me.

vlad_a

The smell in mine is long gone! The AC is off and life is good. Just an inconvenience to go through menus to turn it off. Not a deal breaker at all.

m1964

After the cleaning service done about two months ago I did not feel the smell, but it is back again.
Yesterday we had over 70F + high humidity, and the smell came back. There is definitely something wrong with the design, since my climate control is on "outside air" +"AUTO" when I start the RX. I had never had smell like that in any other vehicles I had owned.

tqh

I noticed that when mine is in "auto" mode, it switches between recirculation (most of the time) & outside air (rarely). I'm not sure if this could be the cause for your mildew problem?
I luckily haven't had that problem, but I don't like recirculation mode so I turned it off using the carista app. Now auto always stay in outside air mode.

HubertNow

They must have something wrong with the design and not only on thr RX model or this is what the filters smell like for the first 20 seconds. First Lexus I owned was a brand new 2010 IS250 and it had the problem, had that car for 2 years and filter were changed 4 times and the smell always came back within couple of months. The next one was a brand new 2013 ES350 and it had the same terrible smell when the A/C was turned on. Dealer changed the filters twice on the ES but the smell always came back. Now I own 2015 RX350 for 3 months and it has same bad smell when turning on the A/C. I haven't went to the dealer with this one yet.
Now I also own 2013 Toyota Tacoma TRD extended cab and that one I own for a year, no such smell exists in the toyota❓❓❓

Dementor

I bought my 2015 RX 350 in Indiana July 2014. By September 2014 with less than 3000 miles, the car started developing the foul AC mildew odor during the first 3 minutes after turning the car on. I had been running the AC on automatic letting the system decide between recirc air and fresh air during the hot months. Took it to the dealer and they said it was a known design flaw and that the problem tended to occur more in cars in the southeast like Florida. They basically ran the heater at high heat (85+F) for a while, then opened up the AC system and wiped dry the AC box, then sprayed some sort of disinfectant which made the car smell like a foot odor spray for the 1st few days. Then they told me to run the AC with free air circulation, especially during the last few minutes before stopping.

After a couple of days, it was back to no odor at start up. But the weather became cooler so there was no need for AC. Been doing fine until last week when the temp finally topped 73 and I started running the AC again with fresh air and no internal recirc. I would even shut the AC off for the last 5 minutes of the trip home. Well the mildew smell came back even though I followed the dealer's advice.

Days got a little cooler so I decided to just run AC off, temp set to high, and leave the windows open on a 30 minutes drive ... now I get dust in the car, but it drys out the AC and the next several mornings as long as I didn't run the AC. Started using the AC again and the mildew problem comes back. The only way to get rid of it is to dry the box out running high heat ... it's not a clogged drain ... it's lack of drain.

This is just a bad design flaw that I would never expect from a luxury vehicle. I've never had this in less expensive vehicles from Nissan, Toyota, and Honda. This is the last Lexus I'm ever gonna buy, they just completely ruined the experience. I would only consider Lexus again if they offer to fix this defect.

On the internet, there have been a few court cases regarding this in which the owners managed to get a refund, but this is just a pain to have to jump through for a solution to an otherwise nice vehicle

novaman

If you are getting a moldy smell from AC you should turn up temperature( if AC in Auto) to a higher temp so warm or hot air is blowing through vents for a minute or two and that will dry out evaporator core just before shut down of vehicle. However, I have a 2015 RX and haven't had the mold smell problems, yet anyways. As far as the re circulation button is concerned it cycles between outside air and inside air. When inside air is selected is usually on start up when the vehicle is hot inside and needs a quick cool down. However, too much inside air selection will cause some dirty sock syndrome smell, I believe. Thus turning up temperature control so heat is flowing just before shut down should help. Pain in the butt, yes. I believe that it's a common problem in lots of vehicles.

novaman

greeknasty

my 01 es has this smell
04 G35 Coupe has this smell
2009 Nissan Maxima has this smell
2014 RX350 has this smell

flaw or not i havent ever had a car that doesnt have that smell. while i wish i would never have it i guess ive just gotten used to it(it does go away within seconds)

novaman

Yes, it's too bad it happens. I owned a 1999 Toyota Camry and it was an issue in this vehicle, too. That's when I started turning up the heat before I shut car off. It was easy as it had manual air so I would just crank the heater temp dial for a few seconds. Some one else in this thread suggested that it could be more of a problem in hotter climates, like southern USA. I agree with that as I live in south eastern Ontario and of course we only have about 4 or 5 months at best of cooling conditions and then heat for 7 months or so.

novaman

Dementor

Seriously, I've had multiple vehicles in hot and humid climates from lowly Nissan Sentra, Toyota Camry, Honda Accord, Honda Odyssey. None of them ever had this problem. This just plain ruins the Luxury experience and I might as well go back to non luxury cars.

Anyway it appears the solution is to turn the AC off for the last 5 minutes of the drive, open the windows, turn the heat to high and fan to full blast and try to not feel uncomfortable with the heat and moist air coming out the AC. When in the garage, set temperature back to desired setting, turn the AC back on, press auto, and immediately turn off the car. Leave the moonroof open or partially open the side windows to allow moisture to leave the interior. The next morning, the car is set to go without the odor.

If one wants to do the spray the vent with lysol, there are youtube videos on it, but I think the best way to do this is to open the glove box and remove the cabin air filter so it doesn't get gunked up. Open all the windows, start the car, turn the AC and fan full on and spray a half can of lysol in the vents in front of the windshield. Set to hi heat and spray the other half of the can in the vent. Turn everything off and put the cabin filter back in.

Bad Lexus. Bad.

vlad_a

As an old habit, I turn off AC in my STi when I'm close to home (less than a minute). It is just a push of a button, so no big deal.

Occasionally, the RX has some mold smell upon start-up, but it is still early in the season for us and I turn the damn thing off when the temps warrant it. That sure helps rather than running it for no reason all the time.
I also fight the auto-recirc-on mode each time the car starts with AC on. At least there is a button, so less cursing.

Bad Lexus indeed!

Dementor

During the 1 year maintenance, I had my lexus dealer work on the AC. This is what they told me:

1. Since 2010, the government made some sort of requirement that the AC systems should automatically go in to recirc mode of the time. Prior to 2010, manufacturers were only required to put the AC into recirc mode no more than 20-30% of the time. This is to maintain some sort of emission standard. The net result is that condensation develops on the evaporator and it doesn't dry out unless the car is left in fresh air mode just before turning it off. The outside heat combined with the moisture on the evaporator results in the mold smell

2. Tell the customer to put the AC into fresh air mode before turning it off. For newer model cars, the manufacturers may change the programming so the system goes back into fresh air mode upon turning the car off.

3. The service center is using a disinfectant that has reportedly stopped at least one other car from having the mold odor. They basically clean out the AC system and fill the evaporator box completely full with the disinfectant to clean it out.

4. The drain tube at the bottom of the evaporator box is a little high in position. This results in water that will never drain out of the box entirely. This is a misdesign in my opinion and results in stagnant water for mold and mildew to grow in.

Net result of the service upon pickup:

a. AC running and the disinfectant was pleasant. Much better than the one they used last year -- AC odor at 2 months after delivery of my RX with cleaning at about 3 months.

b. The interior vents were all moist, presumably from the disinfectant being blown through the system, but not dried out.

I'll see how long it lasts, but it was already raining and humid out and with the AC off, I could feel the humidity coming through the vent system in fresh air mode.

Things I have tried and I know failed

1. Leaving the AC on and keeping the car in fresh air mode continuously (and making sure that it is in fresh air mode for the last 5 minutes of the trip)

2. Turning the AC off. and putting the fan on high for the last 5 minutes of the trip. This works better than (1), but I can feel the humid air blowing into the cabin from the evaporator box

What seems to work a little better at drying out the box:

1. Manually turn off AC whenever car is cool enough and turn it on occasionally when needed -- driver distraction

2. Last 5 minutes of the trip: AC off, fan to fastest speed, heat to max, windows and moonroof vented, vent setting to upper vents. A little unbearable but the humidity from the evaporator box is evaporated away and blown out the windows so the interior is not so humid. Open windows makes the car interior dusty ...

3. Just before turning the car off, fan down to low setting, temperature set to desired car starting temperature, AC on, car off. Leave the moonroof vented and/or leave the driver and passenger side windows slightly open so interior can dry out ... still can make the car interior dusty if opened to much.

My car interior is still sparkling clean and nearly brand new at 1 year old, but it gets harder to keep it clean with all this venting stuff


On a different note, my service person tells me that there is a new requirement to use water based paints for the cars -- this makes it difficult to match paints after an accident.




I'll report back as the rest of the summer progresses.

7/11/15:

After running the car and AC a couple of times, the vents are still moist as the residual disinfectant gets blown out of the box.