Smelly stinky socks / mold in Model 3 AC

[BeeGood]

After watching the video you linked and recalling when I smell the stink, do you think it's possible that the bad smells are coming from the aero shield area where the drain hole pours to? I only get the smells after the fan stops blowing for 15-30 minutes. Looking at the video, it doesn't look like there's much decay or bacteria growth in the coils/filter area. Maybe the bad smells is back flowing through the drain hole from the aero shield area whenever the fan is off? The car honestly doesn't smell bad at all while the fan is running, it's always just a blast of sour smell for the first 30 seconds or so of turning on the car.

That’s what I’m thinking, either on top of the aero shield or maybe in that hole where the liquid drips out of. I just have a hard time believing it’s 100% the filter, or 100% the coils. If it were, I’d expect it to be more persistent and not just go away seconds after turning the AC on.

I tried an experiment where I mixed Lysol from concentrate and slowly poured it into the intake vent so it would run out of the drain hole. It ran out of the bottom of the car like you’d expect and I heard it hitting the aero shield. I’d like to say it helped but I'm not 100% sure because I changed the filter and did the coil cleaner a week later and the smell was faint to begin with. I’m pretty sure there was no smell for that week but I can’t say for certain. This was all in January and I’ve been odor free since then. If it comes back Im going to try it again and see if it works.

 

[texas_star_TM3]

AC on "auto" setting 100% of times

cabin overheat protection "fan only"

no smell in over 26k miles and nearly 3yrs and living in North Texas where it can get quite humid and the AC runs a lot. Especially cabin overheat protection enabled to use the AC will run the AC *a lot* when parked outside during the day and the coils never get a chance to dry off.... hence constant moisture and bacterial / fungus/ moldy growth

 

[jjrandorin]

Thanks! And to be completely transparent, a lot of what I’ve tried and learned was from comments on this message board so it’s been a community effort.

One small thing I’d change after re-reading…I didn’t mention in the second paragraph that you need to pop the vent cover off before you see the vent opening (it’s just second nature to me so I completely forgot).

I’d also add this to the list of remedies (with some hesitation):

• Turn fan on low, open the frunk, pull off the vent cover and spray lysol into the intake. My hesitation here is that when I did it, the lysol smell lasted for weeks and I don’t think it really did much to eliminate the odor. If you do this, I’d recommend it as an additional step to the coil cleaner and removing the filter first (so it doesn’t just soak up the spray)

The best way for me to handle that would be for you to copy the text from your post, make any edits you want to make, then send it to me in its entirety in a PM. I can then create a sticky post with the information, posted as me, but with proper credit to you in the post. For an example of what I mean by that and how it looks, you can take a look at the "how does dashcam work" sticky:

Dashcam / Sentry: How they work and what they do (and dont) do

(moderator note) Special thanks to @Knightshade , for taking the time to write up a description of how Sentry and Dashcam interact together. There is a lot of confusion about these two features, and how they interact together. I asked @Knightshade who has a good understanding of how these...

teslamotorsclub.com

Alternatively, you could create a new thread, PM me with a link to it, then I could make it a sticky thread. Either way works. Sometimes people prefer the sticky note come from "a mod" even if we are not creating the content, so thats why I do it the first way sometime.

 

[jjrandorin]

AC on "auto" setting 100% of times

cabin overheat protection "fan only"

no smell in over 26k miles and nearly 3yrs and living in North Texas where it can get quite humid and the AC runs a lot. Especially cabin overheat protection enabled to use the AC will run the AC *a lot* when parked outside during the day and the coils never get a chance to dry off.... hence constant moisture and bacterial / fungus/ moldy growth

You might be onto something on the cabin overheat protection. I have mine set to fan only as well, and like you have no issues. The only issue I had was in early to mid 2019 before tesla changed the algorithms on how the fan runs.

 

[XPsionic]

You might be onto something on the cabin overheat protection. I have mine set to fan only as well, and like you have no issues. The only issue I had was in early to mid 2019 before tesla changed the algorithms on how the fan runs.

Another (counter) data point. I've got my cabin overheat to fan only as well, but I had to use recirc frequently due to the excessive pollution in LA traffic jams causing headaches (and yes, recirc actually helped, it was a years long quest to find out why we get headaches, and it's literally the air pollution).

Manually recirculating definitely has something to do with the stinky smells, before using it (leaving everything on auto) the car never smelled like anything, not long after starting to use recirc, YIKES. I've done the filter change and 2 round of sprays of the coils and it helped but not eliminate the smell.

That got me thinking, where is the recirculation flap/valve? I swear the smell has something to do with it and it'd be nice if I could clean/spray that area.

 

[mdance428]

You might be onto something on the cabin overheat protection. I have mine set to fan only as well, and like you have no issues. The only issue I had was in early to mid 2019 before tesla changed the algorithms on how the fan runs.

I took delivery of my 2021 M3 SR+ in November. I've rarely used recirculation and have had cabin overheat protection to fan only and had no issues in upstate South Carolina. When my Tesla mobile service rep came to fix a warranty issue, I asked about preventing the air stink, he recommended changing the cabin filters every 6 months, which yes, is more frequent that any other car, but $70 in filters a year that may prevent this issue? I'll take the risk.

 

[SabrToothSqrl]

Wife's car has the funk, after paying to have it defunked 2x now, I think I need to start doing it on my own.

 

[texas_star_TM3]

I took delivery of my 2021 M3 SR+ in November. I've rarely used recirculation and have had cabin overheat protection to fan only and had no issues in upstate South Carolina. When my Tesla mobile service rep came to fix a warranty issue, I asked about preventing the air stink, he recommended changing the cabin filters every 6 months, which yes, is more frequent that any other car, but $70 in filters a year that may prevent this issue? I'll take the risk.

doesnt make a lot of sense as the filters aren't where fungus/ mold/ bacteria/ slime is growing...

 

[MikeyC]

You might be onto something on the cabin overheat protection. I have mine set to fan only as well, and like you have no issues. The only issue I had was in early to mid 2019 before tesla changed the algorithms on how the fan runs.

I'm in FL and have used cabin overheat protection with HVAC on auto from day one. My filter/coils get stinky about every 4 months. 2021 MY.

Mike

 

[texas_star_TM3]

I'm in FL and have used cabin overheat protection with HVAC on auto from day one. My filter/coils get stinky about every 4 months. 2021 MY.

Mike

i think *not* using cabin overheat protection with AC on is key... you are literally running the AC for hours every day and the coils never dry and stay damp / mildew grows and you dont have airflow from driving either. on the other side... parking outside with cabin overheat fan only... will dry out the coils nicely while still pumping cooler outside air into the cabin

 

[MikeyC]

i think *not* using cabin overheat protection with AC on is key... you are literally running the AC for hours every day and the coils never dry and stay damp / mildew grows and you dont have airflow from driving either. on the other side... parking outside with cabin overheat fan only... will dry out the coils nicely while still pumping cooler outside air into the cabin

I agree. I meant to say, I've always run cabin overheat protection in fan only mode. I don't want my AC compressor coming on with no one in the car. Doesn't seem to matter. Mine still starts to smell like vinegar after 4 months of new filters and coil cleaning.

Mike

 

[ODWms]

Interesting. I’m in Florida also, and had the issue once (slight smell. Nothing big), for about a couple weeks if I remember correctly. I bought a package of the cleaner as well as the 2 filters, but Tesla did an update that changed the way the AC system acts after turning off the car. It all went away before I had a chance to even swap the filters, let alone do the cleaning. Been perfect since. Thats been 2 years maybe, and I’ve had the car 3 1/2 yrs.

 

[MikeyC]

When I got my 2021, that fan update was already there but it doesn't seem to work very well. I think the problem is made worse if you take a lot of short trips. I frequently drive 5 or so miles, park in the heat for 10-15 minutes, drive another few miles, park for a few minutes, then drive home. I notice the stink most after those short periods where the car is parked: I think the short trips give the AC coils a chance to get a lot of condensation on them which, once parked, drips onto the filters.

Mike

 

[Nimrandir]

On my old MINI Countryman i used AC only during summer and rarely in winter... And everytime i turned it on, the damp smell would come inside... I would then put the AC on to the max temperature for some minutes at full speed. After that the smell would go away. So this "smell gate" its not just a Tesla thing.

As other have said keeping the AC on recirculate all the time isn't a grea idea. You're supposed to use that funcion for brief moments to heat o lower the temperature of the car quickly. Keeping it on, will use the same air inside the cabin, not allowing fresh air inside and you'll keep breathing the same air. During winter times, you will notice also that your windows will fog very easily if you keep it on all the time.

Interesting read: What does the air-recirculation button do? - Eden Tyres & Servicing

 

[texas_star_TM3]

c

On my old MINI Countryman i used AC only during summer and rarely in winter... And everytime i turned it on, the damp smell would come inside... I would then put the AC on to the max temperature for some minutes at full speed. After that the smell would go away. So this "smell gate" its not just a Tesla thing.

As other have said keeping the AC on recirculate all the time isn't a grea idea. You're supposed to use that funcion for brief moments to heat o lower the temperature of the car quickly. Keeping it on, will use the same air inside the cabin, not allowing fresh air inside and you'll keep breathing the same air. During winter times, you will notice also that your windows will fog very easily if you keep it on all the time.

Interesting read: What does the air-recirculation button do? - Eden Tyres & Servicing

yup. keep AC 100% on AUTO and don't use AC overheat protection when parked... and you very likely will be fine. AUTO turns recirc on/off repeatedly during a drive and likely with the intention to find a good balance between drying out the coils and running the system most efficiently.

 

[Need]

c

yup. keep AC 100% on AUTO and don't use AC overheat protection when parked... and you very likely will be fine. AUTO turns recirc on/off repeatedly during a drive and likely with the intention to find a good balance between drying out the coils and running the system most efficiently.

That's exactly what I do. I think the main help is turning off cabin overheat protection.

 

[texas_star_TM3]

That's exactly what I do. I think the main help is turning off cabin overheat protection.

i also always use navigation even when just driving back in my city to the home. that way the car "knows" when i will be home and likely starts drying out AC coils with "fresh air"

 

[Need]

i also always use navigation even when just driving back in my city to the home. that way the car "knows" when i will be home and likely starts drying out AC coils with "fresh air"

Interesting. I do it all the time too but not for the same reason. I know how to get home, but the freeway near my house turn traffic red all the time. So I will let the car route me either thru local or freeway depending on the traffic even if I just went grocery shopping. I didn't know that it would help "drying out the coil" as well!

 

[Scubadriver]

On my old MINI Countryman i used AC only during summer and rarely in winter... And everytime i turned it on, the damp smell would come inside... I would then put the AC on to the max temperature for some minutes at full speed. After that the smell would go away. So this "smell gate" its not just a Tesla thing.

As other have said keeping the AC on recirculate all the time isn't a grea idea. You're supposed to use that funcion for brief moments to heat o lower the temperature of the car quickly. Keeping it on, will use the same air inside the cabin, not allowing fresh air inside and you'll keep breathing the same air. During winter times, you will notice also that your windows will fog very easily if you keep it on all the time.

Interesting read: What does the air-recirculation button do? - Eden Tyres & Servicing

Not sure this logic holds for hot, humid environments. Recirculation will dehumidify the air relative to the hot, humid fresh air.

 

[texas_star_TM3]

Not sure this logic holds for hot, humid environments. Recirculation will dehumidify the air relative to the hot, humid fresh air.

I'm just a big believer in the AUTO setting. that way you let the AC system do what Tesla engineers want...