I am trying something new. I got the smell again. Instead of changing the filters and cleaning the coils, this time I just pulled the filters out and sprayed them down a good amount with Lysol. I put them right back in. Right now it just smells like Lysol but I will report back in a few days.
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Antifungal spray for cabin air filter
- Thread starter Level8Drummer
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M109Rider
Active Member
Bacteria can grow just as easily from the same food source mold can. Pretty much anything organic, including skin or animal dander. It also thrives and grows in wet or damp conditions with that food source. It doesn’t have spores like mold, but doesn’t need them like mold does to spread and to grow either.Most sites that mention the vinegar smell in car AC say it's from mold. The sour smell comes from mVOCs which mold can generate and release:
What Does Mold Smell Like & How Can You Tell?
In this article, we'll break down what mold smells like and how to differentiate from other smells that are commonly mistaken for mold.greenorchardgroup.com
While it's true bacteria can also generate acetic acid that smells like that, generally bacteria can't spread as easily as mold airborne and it isn't as well known to thrive in damp conditions. Bacteria being the culprit increases if there is a lot of debris and decaying matter or standing water, but generally in most cases it's just wet coil/fins, which suggests mold/mildew. It's possible that they are co-inhabitants, but generally for AC coils/fins, mold is typically the one blamed primarily for it.
People smell something funny, and they always say it’s mold. Even the sites you said state the vinegar smell is mold likely have no idea if it’s mold or bacteria.
Once you start smelling mold, you often can see it, or very soon after. In any of the pictures I’ve seen from folks and their smelly Tesla HVAC systems, I’ve never seen mold on the coils or fins.
Bacteria, on the other hand is not visible….
Both mold and bacteria emit strong odor when wet or damp.
The only way to know if it’s mold, bacteria, or both, is to swab, and grow it in a petri dish.
I have smelled mold and bacteria many times over. That smell in my experience is likely bacteria, and not mold.
The website you linked offers a service cleaning mold( lol ) and says that pretty much every type of smell is mold. No mention of bacteria….
stopcrazypp
Well-Known Member
One way to test is to use a cleaning agent that only kills bacteria and one that only kills mold and see which one works. If either one doesn't work and the other does, then that kind of tells you what the culprit is.
I use that site only because they actually name what chemical causes each smell. Many sites don't go to that detail.
M109Rider
Active Member
Except that the cleaning process alone, for one or the other, would likely also effectively wash away enough of both to spoil the test.
In the end, it still needs to be cleaned. My point was to those claiming that breathing this odor in would kill them. Even if it is mold, that small amount in the fins of the hvac is likely less exposure than the amount of mold spores organically floating around them currently outside.
Mold is mostly dangerous in quantity and duration.
1 square foot of minuscule amounts on your fins is not. You may be allergic to mold spores, or it might play with your asthma, but that would happen just walking to your car with the spores naturally present in the air. Different quantities through out the year depending on the season.
stopcrazypp
Well-Known Member
Ok, fair point, I agree the health problems probably is minimal. Most people however I think just want to eliminate the unpleasant smell, they don't really care that much if the source is actually really eliminated. No one for example have mentioned allergic reactions.
I've posted previously human smell just works better in warmer and humid conditions, which is why the smell is strongest at startup. With the AC running you are likely still breathing a lot of the same substance, just that you don't perceptively smell it anymore.
M109Rider
Active Member
There were one or two stating the mold they are breathing in could be harmful. I do respectfully disagree with the premise that you don’t keep smelling it, because your perception goes away, or you are desensitized.
That is a real thing for many scenarios. However, if you get out of the car, then get back in while the AC has been running, you won’t smell that same start up smell.
stopcrazypp
Well-Known Member
I think both likely still plays a factor. In the AC situation, the air is colder and less humid, which also reduces your perception.There were one or two stating the mold they are breathing in could be harmful. I do respectfully disagree with the premise that you don’t keep smelling it, because your perception goes away, or you are desensitized.
That is a real thing for many scenarios. However, if you get out of the car, then get back in while the AC has been running, you won’t smell that same start up smell.
M109Rider
Active Member
Hate to say it, but you may not have cleaned the condenser fins well enough.
I’ve had this done twice, and it’s worked for at least two or three seasons.
I've managed to eliminate the terrible smell for good!
4 months update since I used a 19oz bottle of Frost King to deep clean the coils: bad smell came back after about 2 months of cleaning and changing filters, but I found a solution! Even though the car is supposed to run the fan with AC off after we get out, the smell remains terrible after short stops. What I do now is manually turn off AC 30 seconds before getting out of the car, and turn fan to 8-10 speed with recirculate off. This has completely eliminated the smell issue. I still use recirculate mode manually when I'm stuck in traffic, but as long as I remember to dry out the AC coils until the air blowing out isn't cold anymore, there's no smells.
Wish the car could do this properly automatically, I KNOW it's SUPPOSED to do this, but obviously, it doesn't work as well as what I do manually, because now the smell's gone!
Additional info about what I tried to do to eliminate the smells, and some myth busting: my car used to smell great before I toggled recirculate mode on manually on congested highways, from then on it smells sour and terrible especially after short trips and stops. I've changed filters and noticed that the filters were clean and did not smell bad or have any visible fungus or mold growth, and they don't smell bad even when the filters were wet. So the culprit isn't the filters. I've tried different cans of AC foam cleaners, all work more or less, but the smells would come back anywhere between 2 weeks and 3 months no matter how giant a can the foam is and it also didn't matter when I used a 90 degree nozzle to inject the foam right into the coil fins. Also tried anti fungal sprays from the intake and that didn't really work. I tried spraying with and without the filters installed.
TLDR: Before getting out of the car, run fan on max speed with AC off and recirculate off until air isn't cold anymore, smells gone!
4 months update since I used a 19oz bottle of Frost King to deep clean the coils: bad smell came back after about 2 months of cleaning and changing filters, but I found a solution! Even though the car is supposed to run the fan with AC off after we get out, the smell remains terrible after short stops. What I do now is manually turn off AC 30 seconds before getting out of the car, and turn fan to 8-10 speed with recirculate off. This has completely eliminated the smell issue. I still use recirculate mode manually when I'm stuck in traffic, but as long as I remember to dry out the AC coils until the air blowing out isn't cold anymore, there's no smells.
Wish the car could do this properly automatically, I KNOW it's SUPPOSED to do this, but obviously, it doesn't work as well as what I do manually, because now the smell's gone!
Additional info about what I tried to do to eliminate the smells, and some myth busting: my car used to smell great before I toggled recirculate mode on manually on congested highways, from then on it smells sour and terrible especially after short trips and stops. I've changed filters and noticed that the filters were clean and did not smell bad or have any visible fungus or mold growth, and they don't smell bad even when the filters were wet. So the culprit isn't the filters. I've tried different cans of AC foam cleaners, all work more or less, but the smells would come back anywhere between 2 weeks and 3 months no matter how giant a can the foam is and it also didn't matter when I used a 90 degree nozzle to inject the foam right into the coil fins. Also tried anti fungal sprays from the intake and that didn't really work. I tried spraying with and without the filters installed.
TLDR: Before getting out of the car, run fan on max speed with AC off and recirculate off until air isn't cold anymore, smells gone!
The kool it can isn't large enough to clean out the AC system on a Model airplane.
It is not likely that running fan only for 30 seconds a difference. You aren't drying much in 30 seconds and odds are your coils are even still cold from the AC running 30 seconds ago.
Are you preconditioning your car or do you have cabin overheat protection turned on? The smell typically goes away after the first few mins of the AC running so if you precondition you don't smell it. If you have cabin overheat on you don't smell it either when it's hot enough to turn on.
I typically get the smell once or twice a year. I just got it again so just spraying the air filter with Lysol and trying to reuse it doesn't work at all.
Today I sprayed Lysol into the coils using the tube from a previous time that I had kilma cleaner. I also replaced the filter with a cheap $10 set. We will see how long this lasts.
Today I sprayed Lysol into the coils using the tube from a previous time that I had kilma cleaner. I also replaced the filter with a cheap $10 set. We will see how long this lasts.
I *just* finished doing mine. The filters were 2.5 years / 45k miles old but had very little debris. Didn't look that dirty.
I cleaned with Kool-It, ran the fan on low for a bit until it was dry, put in the new filters, the smell is gone. Crossing fingers it doesn't come back too soon. Mine didn't start smelling until towards the end of it's second summer.
I cleaned with Kool-It, ran the fan on low for a bit until it was dry, put in the new filters, the smell is gone. Crossing fingers it doesn't come back too soon. Mine didn't start smelling until towards the end of it's second summer.
No offense intended, but your assumptions are probably incorrect. I'll explain why drying/warming up the coils worked when all the other things everyone else suggested didn't. And I tried every suggestion multiple times over the last 18 months.
I purposely did not use preconditioning to see if the smell is different. Before doing the ac off ritual it always smelled terrible right after getting back into the car, after the ritual, zero smells. I also don't use overheat protection, fan only mode for that. I park in a climate controlled garage all the time anyway.
My car smelled great for the first year, in the second year of ownership I started using recirculate mode manually once in a while and that's when the smells started.
Here's all the things I tried individually to narrow down the source of the smell or to eliminate it over the last 18 months:
New filters: didn't work, filters didn't smell bad nor were they dirty/moldy, making the old filters wet doesn't make them smell bad either. Myth that the filters get wet inside the car creating the smell is busted.
Anti fungal sprays: tried blasting the spray in from the outside air intake with and without air filters installed. Has limited success, only got rid of the smell for a few days at most.
AC foam cleaner: tried 4 different kinds, they all work for weeks or even months at a time but the smell will come back 100%. The size of the can matters, but >10oz worked best.
Not using manual recirculate mode anymore: once the ac smells, this doesn't eliminate the smell.
Using recirculate mode all the time: this just makes the car smell stale and the terrible rotting smell comes back the quickest this way even after foam cleaning.
Use preconditioning: that gets rid of the first minute of terrible smells, but if I ever forgot to turn it on, holy crap it's terrible! Also the cabin still smells a bit funky anyway with this method.
Don't use over heat protection: mine is only in fan mode, didn't help.
After 18 months of trying all kinds of combinations of cleaners and fan modes, the AC off ritual worked! Just before getting out of the car: Turn off AC, turn off recirculate, fan to speed 10, it won't take long for the air blowing out to warm to ambient (so yes, the coils do warm up quickly, 30s is probably the bare minimum time required). Next time i get into the car, no more smells. I tried this about 10 times, confirmed it worked before posting here.
The car is supposed to do this on its own, but very obviously it didn't work for my car to prevent the smell! And if it did there wouldn't be so many people posting on that's like these.
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First of all, try the ac off, full fan speed ritual I described earlier, after 18 months of trying to get rid of the smells with all the methods described and suggested on forums and YouTube, that's the only thing that worked.
As for AC cleaners, I had good success with a giant can designed for outdoor AC coils. Frost King is the brand, 19oz. It had so much foam I had to do it in 2 batches as it eventually flowed out of the AC coil cavity out into the passenger footwell. This is while using a flexible hose and a nozzle.
I've tried different brands, sizes and nozzles, get one with a flexible hose with a nozzle that you could aim directly at the coils. It takes about 12oz to completely fill the cavity with foam.
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stopcrazypp
Well-Known Member
That ritual matches what I did in my old ICE car, but in that one it was more an effort for efficiency (near destination on local roads it is more efficient to have windows down and AC off, plus my climate is moderate enough that it's cool enough).
If people try this and if really works perhaps this can be somehow suggested to Tesla to add a mode to automate it.
From what people have been saying in these forum threads, they do have AC coil drying automated in some fashion. This was added to the software back some time in 2021. I think the automated drying mode does work most of the time because not everyone complains about the smell. Unfortunately once the car start stinking, maybe the automated mode coded in by Tesla isn't aggressive enough in drying out moisture, because no matter if I toggle the recirc on or off before parking, the stink continued until I started doing the AC off/Max fan ritual.
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