Rotten egg smell… not sure it’s the AC.

[AZAV8R]

Having already done 2 cabin air filter swaps, I am well familiar with the funky smell that a moldy evaporator can cause. I had a weird experience today. I’d left HAL parked with camp mode set to 60f. (I had take- home restaurant food and needed to make a 30 minute stop.) At the time, the OAT was about 110f in Tucson. When I opened the door to get in, the smell of rotten eggs about put me on my knees. It was REALLY NASTY!! My first thought was a failing 12v battery, but I replaced it back in April with an Ohmmu. To my knowledge, lithium batteries do not smell like that when they fail (they just cause nasty fires!! 🤪). No warnings or messages. The smell dissipated quickly and did not return on that trip. I will go out tomorrow am to see if happens again.

2020 M3LR.

I’m pretty sure I have a decent handle about how my car works, but this stumps me. Feedback from some knowledgeable folks here will be appreciated!

😎😎

 

[Tam]

...funky smell that a moldy evaporator...

I think there's a redesigned air duct to get rid of the smelly A/C in Model 3. You'll just need to pay additionally for Service Center to upgrade for you.

 

[AZAV8R]

I think there's a redesigned air duct to get rid of the smelly A/C in Model 3. You'll just need to pay additionally for Service Center to upgrade for you.

Thanks. Anyone out there know more info on the upgrade?

 

[Tam]

Thanks. Anyone out there know more info on the upgrade?

Maybe I didn't remember that correctly: it could be that there was no new air duct redesign: just plain maintenance of cleaning the area and switching the filters yearly or every few months.

 

[Frank99]

I haven’t heard of a strong rotten egg smell that wasn’t related to either a lead acid battery, Yellowstone, or a rotten egg. I’ve got no help for you other than suggesting looking under the seat to see if an egg got loose the last time you went shopping.

 

[Kimmi]

Bad catalytic converter?

 

[Long Ranger]

I had take- home restaurant food and needed to make a 30 minute stop.

What was the food? My guess would be concentrated food odors. Or perhaps your “Ohmmu” battery was purchased at a discount and was just as heavy as the original battery?

 

[RayK]

It was.... "Spleen"!

Other than that, my initial response would have been your (OEM) 12V battery but I see you've replaced it with an Ohmmu. Natural gas, the municipal energy source, can also smell like rotten eggs, as well as drinking water in some rare cases. Or something crawled into your car and died.

 

[m a x i m u s]

Bad catalytic converter?

Beat me to it

 

[AZAV8R]

It has never returned, despite efforts to reproduce the circumstances. Moving on... 🧐

 

[Frank99]

One last thought-perhaps you were parked over a manhole cover leading to the sewer. This time of year there can be some pretty rank air around them.

 

[dduffey]

Having already done 2 cabin air filter swaps, I am well familiar with the funky smell that a moldy evaporator can cause. I had a weird experience today. I’d left HAL parked with camp mode set to 60f. (I had take- home restaurant food and needed to make a 30 minute stop.) At the time, the OAT was about 110f in Tucson. When I opened the door to get in, the smell of rotten eggs about put me on my knees. It was REALLY NASTY!! My first thought was a failing 12v battery, but I replaced it back in April with an Ohmmu. To my knowledge, lithium batteries do not smell like that when they fail (they just cause nasty fires!! 🤪). No warnings or messages. The smell dissipated quickly and did not return on that trip. I will go out tomorrow am to see if happens again.

2020 M3LR.

I’m pretty sure I have a decent handle about how my car works, but this stumps me. Feedback from some knowledgeable folks here will be appreciated!

😎😎

You already addressed this, but I woke up one day with the garage smelling like rotten eggs due to 2018 M3 12v battery failed (no warnings). It was dead enough that the car didn't turn on / HV connecter would not click, but just enough power that it would not let me pop the hood w/ the tow hook wires.

 

[rrolsbe]

You already addressed this, but I woke up one day with the garage smelling like rotten eggs due to 2018 M3 12v battery failed (no warnings). It was dead enough that the car didn't turn on / HV connecter would not click, but just enough power that it would not let me pop the hood w/ the tow hook wires.

So did you just wait for the 12V battery to deplete some more and then open the frunk via the tow hook wires?

 

[dduffey]

So did you just wait for the 12V battery to deplete some more and then open the frunk via the tow hook wires?

In my case after it sat for some time and tried again the HV came on and I was able to back out and pop the hood. I left my hood unlatched for mobile service to replace the battery.

Before the HV was working things would half work like the door would unlock but window would struggle to lower when the door opened.

 

[Dr_Arthur]

Having already done 2 cabin air filter swaps, I am well familiar with the funky smell that a moldy evaporator can cause. I had a weird experience today. I’d left HAL parked with camp mode set to 60f. (I had take- home restaurant food and needed to make a 30 minute stop.) At the time, the OAT was about 110f in Tucson. When I opened the door to get in, the smell of rotten eggs about put me on my knees. It was REALLY NASTY!! My first thought was a failing 12v battery, but I replaced it back in April with an Ohmmu. To my knowledge, lithium batteries do not smell like that when they fail (they just cause nasty fires!! 🤪). No warnings or messages. The smell dissipated quickly and did not return on that trip. I will go out tomorrow am to see if happens again.

2020 M3LR.

I’m pretty sure I have a decent handle about how my car works, but this stumps me. Feedback from some knowledgeable folks here will be appreciated!

😎😎

Hydrogen sulphide can be coming from the 12v battery. The gas is toxic in high concentrations. Change the battery.

 

[AZAV8R]

Hydrogen sulphide can be coming from the 12v battery. The gas is toxic in high concentrations. Change the battery.

Ummm, see my post. I acknowledged that issue and I have a Lithium battery. 😎😎