I struggled for months with a bad vinegar-like smell coming from my Model Y air conditioner, especially when it rained. People would get in my car and ask "Why does your Tesla smell like rotten egg, cheese, vinegar, or feet?" However you describe it, the bad smell was frustrating and embarrassing.
The usual fixes didn't work on it for more than a few weeks, but I finally resolved it with a simple plastic clip on new cabin air filters and a Tesla service bulletin, so I wanted to get this out there for anyone else who may be having a similar, foul smell experience.
First, Try Installing a Moisture Barrier Clip, Replacing Filters, and Cleaning the Evaporator
12/2023 Update: A persistent YouTuber (Adam Davenport) has put a lot of effort into better understanding the root cause of the moisture issue and found that a plastic moisture barrier clipped to the bottom of the air filter helps prevent water from soaking into the filter and causing the smell.
He's freely offering his version to print for yourself or for others to make and sell, but we made our own version that's easier to install and fits the OEM Tesla filters better. They're available here:
Even if they look fairly clean, it's worth putting in a fresh set of filters to rule them out. Here's our bundle that includes OEM-equivalent filters, a set of tools, and a moisture barrier clip:
For cleaner, I prefer DWD2 Clean Air Green over other options I've tried because they give you enough product to do the job in a single can and I prefer the scent of the plant-based, non-toxic formula. Here's our bundle with everything you need to get the job done:
Evaporator Cleaning Process
One of my most-watched YouTube videos goes over the cleaning process, so I know plenty of owners have needed to do it and plenty more have probably paid Tesla to do it.But WHY Does My Tesla AC Smell?
Now, Teslas certainly aren't the only vehicles that experience this, but they do seem to be more prone to it. It may be related to their unique cabin overheat protection feature (that gasoline vehicles don't have) that can run the air conditioner when the car is parked. Tesla even released a software update to modify this feature to combat the smell.
However, this feature may actually be part of the problem! Normally, the cabin air filters’ job is to remove dust, dirt, pollen, and other pollutants from the air, but if those filters get wet, it can promote the growth of bacteria that causes these smells. YouTuber Adam Davenport’s investigation shows that the cabin overheat protection feature can blow condensed moisture in the air conditioner back onto the filters.
Why Does My Tesla Smell After It Rains?
Many owners have found that the smell tends to be worse in rainy weather, which makes sense! The extra moisture in the outside air adds to the moisture in the car and increases the condensed water in the air conditioner that wets the bottom cabin air filter. Operating the air conditioner in recirculate mode will close the fresh air intake and can help reduce the amount of moisture entering the vehicle during rainy days.
When Cleaning and Filters Didn't Work, What's Next?
One difference between my Model 3 and Y is the Y now comes with a heat pump, so I wondered if it was just more prone to the smell. I thought maybe the older resistive heaters in the 3 would get hotter and kill the bacteria better than a heat pump?
I also noticed that the Model Y heat pump was louder in some conditions. I'd hear a hissing noise when it was switching from slightly cooling the cabin to slightly heating. This was happening as long as we've had the car, so I had originally attributed this to a difference in the heat pump, but it seemed to be getting louder, so I was suspicious that something might not be right there.
Then, we had two instances of the air conditioner not cooling the car on hot days. We normally keep it on auto, so it ramps the fan up and down as needed.
Well, we were driving along and noticed that the fan was blowing really hard and the air wasn't cold. In both cases, it worked fine the next time we got in the car, but clearly something wasn't right.
So, I scheduled service. I sent a video of the hissing noise and they also asked for the dates and times the air wasn't cooling to research the logs. Even before they looked at the car, they told me there's a service bulletin they thought was related to the noise issue, so they were going to start there.
The Bigger Fix
Ultimately, here's what they did:
For the service bulletin, they replaced two high pressure and one low pressure refrigerant sensors.
And they also found a refrigerant leak (that was likely related to the loss of cooling), so they replaced a refrigerant line and refilled the refrigerant.
Neither Tesla or I were confident that these issues had anything to do with the smell, but here we are over a month after those fixes and two months after the last evaporator cleaning and the smell is now resolved also!
Of course, Tesla did the repairs under warranty, so no charge there, but prior to that I had spent several hundred dollars on filters and cleaners between my attempts and paying Tesla to clean it, so I'm really happy to be done with that!
So, moral of the story, if you're having any of those issues, like a smell that won't go away, a hissing sound, or loss of cooling, I hope this helps you resolve it!
If you'd like to hear the hissing sound for yourself, you can check it out in our video below:
