Corolla Sedan 2018 - air con stinks when turning on the car

[adamm]

Hi,

I have problems with Corolla 2018 for the second time, after few months of air-con filter change and car wash, it starts to stink when turning the car on from the air con.

In a service facility, they don't know anything, except that I can pay filter replacement and aircon cleaning, but I'm started to feel like a fool for taking 2nd irregular aircon service (on my expense).

Does anyone know anything about this problem? Any piece of advice?

 

Thanks

[TonyHSD]

Hi and welcome. 
Air con has a drainage pipe that goes under the passenger carpet close to the glove box, you will need to get that checked for eventual blockage and holding of condensation water inside the dash , this is usually where the bad smell comes from. If the pipe is ok and waters goes out easily then you need to look for under the Wiper Blades tray there  are also drainage canals that let any rain water goes through the body of the car and out from somewhere under it, check that for any debris and leafs from trees especially if you park your car under trees. Check also passenger carpet near the seat for any water or moisture, this can point you toward all above. Then if all ok what can you do to kill bacteria  in your air ducts is after a drive or with engine hot set temperature to max and blower fan to speed 2 and blowing towards feet and middle vents close all doors and leave all 4 windows slightly open, leave the engine running for 20 min, stay around the car though and watch, after the time switch blower to blow towards windows for another 10 min again at max heat, this will rise temperature kill the bacteria and dry your interior. You should have no issues after, or if there is an improvement but not enough just repeat the process. Check cabin filter if it’s clean and dry too. 
Good luck. 

[Leo63]

Hi check the pollen filter this could be damp or blocked if so it needs changing