A/C Hum Sound normal?

A/C Hum Sound normal?

I'm an ecstatic owner of a 40kW Model S in Miami with 1,000 miles already. Placed my order 4 years ago.

My AC makes normal fan noise, just like any other car I've driven. The thing that was always apparent to me from my first drive is a loud hum (low frequency tone) it makes when it (the AC) tries to achieve a colder temperature. It makes that noise for a couple of minutes when you first turn the AC on. I'm not talking about fan noise, it's more of loud tone coming from the frunk.

Btw, I know an ICE car makes a lot more noise than the Model S in any scenario. I guess the only reason it bothers me is that the A/C sound always comes in strong just when I am to showing off to my friends about how quiet the Model S is... hehehe

I guess my question is, is this a normal sound from the a/c of the Model S?

Happy Trails.

markapeterman | 5 juillet 2013

I have this sound also - it is the AC compressor going full speed when first starting up - see link:

It would be nice if it eased into it - I agree it sounds like a freight train right as you start showing off the car. Maybe they can fix it on a future firmware upgrade - it clearly got worse with a recent vesion.

TomasT | 5 juillet 2013

@ markapeterman Thanks for making me feel like I'm not the only one... LOL You should see me turning the A/C on with the iPhone app a couple of minutes before my friends get in the car. hehehe
It's like a hate showing them that the car has any flaws at all..

Yeah. I hope there was a more elegant way of the compressor to come in. Maybe a bit more sound insulation for that particular part of the a/c...

LuvTesla | 6 juillet 2013

Same here!

Jewsh | 6 juillet 2013

Indeed the A/C compressor works well but certainly isn't discreet. Maybe in the future Tesla will use TECs or something less noisy. (Although the peltier effect is not particularly energy-efficient it produces no noise...)

olanmills | 8 juillet 2013

I'm not sure if I have the same problem or something different, but I hear this occasionally. I goes away immediately if I turn the climate control off and then back on.

Brian H | 8 juillet 2013

Why do you goes away?

Sounds like a reportable glitch. Just for info purposes, if nothing else.

Carefree | 9 juillet 2013

olanmills - how hot is it where you live? I used to be able to get rid of the "hum" when the temps were moderate by turning the A/C off and on again. Now that we have above 100F weather in AZ the compressor hum lasts for a couple of minutes and turning off/on the A/C does not change that at all. It sounds like a jet engine at take-off:-)

Your car is most likely behaving perfectly normal.

dtesla | 9 juillet 2013

I also get a noise from my A/C when it is running flat out. I also get a vibration in the steering wheel. Does anybody else experience this vibration?

Wooly | 9 juillet 2013

Yes, I have the loud humm/buzzing too. In no way shape or form should this be considered normal or OK. Tesla needs to do something to fix this. It really takes away from a wonderful driving experience. People immediately say, "what the hell is that?". It is somewhat embarrassing as you are showing others the car and very disturbing to me as the driver. Lets go Tesla. You created an amazing 85kwh battery and supercharging stations. You can get rid of that awful buzzing! Bad.

mwojcie | 10 juillet 2013

It is a fan to cool the battery pack. When the outside temp is high and you are using lots of juice it really cranks up - if you drive it hard or use the AC on high it will get louder. If you drive the car hard even with the AC off it will still come on - even after the car is turned off - to keep cooling the battery pack. Hopefully they will come up with a better way that is less noisy.

Carefree | 10 juillet 2013

mwojcie - it is not the fan itself. The hum comes from the compressor and does go away after a few minutes. By pre-cooling the car from your smart phone you can avoid the embarrassment.

TomasT | 10 juillet 2013

From what I read in many posts, if they move and tie some things around, the compressor wouldn't vibrate against the steering shaft or frunk liner, therefore less of the awful sound and no steering wheel vibration.
Not sure if this little operation would be covered under warranty or if they would treat it as normal sound. When I bought it the salesman said the sound was normal. I guess I should call my Dania Beach service center and find out myself if they will do it.

Like @markapeterman mentioned this is a good link to this whole a/c compressor sound situation.

Carefree | 10 juillet 2013

TomasT, it will help somewhat. I had the strong vibration coming from the compressor and the sound was incredibly loud. The Tesla SC in Phoenix got rid of the vibrations for me but the compressor is still very very loud for a few minutes.

TomasT | 10 juillet 2013

Thanks Carefree. If it doesn't change that much then I think I'll just live with it until the 1 year service and have them take a look at it then.
I appreciate your feedback. I'm also glad I'm not the only one that gets embarrassed by the sound when friends get into the car... :-) I'm filing this one under the "early adopter tax" file. Still really happy with this car.

AmpedRealtor | 10 juillet 2013

Isn't it funny that we complain about loud AC compressor noise, yet we never complained about the even louder noise coming out of our ICE vehicles... :)

mdtaylor69 | 10 juillet 2013

Mine seems to hum more when I include the defrost on the blow options. I set it to just blow from the upper vents and the loud hum has decreased.

Brian H | 10 juillet 2013

Needed: a quiet compressor. ;(

HaroldS | 10 juillet 2013

The noise is certainly from the compressor itself -- it you don't believe that just take the frunk liner out and you can see and listen to the compressor. Put your hand on the housing and feel the pulsation.

I was showing our Signature at a car show this weekend, in the hot sun in the 90's (yes, I know -- not hot for those of us from Texas or Arizona) and it was terribly embarrassing to run the A/C because the noise sounds exactly like an impeller blade hitting the housing of the compressor.

I tried, but no one at the show believed Tesla's story that it is "normal". Actually, if by normal they mean the whole d@#$m batch of these things have the same design flaw, then OK. However, I would never accept that level of noise as normal in any car.

TomasT | 10 juillet 2013

A couple of years ago there was a particular series of Mac Pro's (back then they were called PowerMac G4) that made a suoer loud fan noise whenever they got hot. It was so loud that they were nicknamed WindTunnel G4's. LOL The loud fans got the job done, (those computers lasted decades and kept working), but for sure Apple changed them for the next generation to a more quiet fan and much cooler design.

At some point in the future we will be talking about our 1st Gen Model S... "Remember that noise it made when the A/C compressor kicked in! Yeah!! It was like a plane was taking off..." LOL

It's all good. I loved my PowerMac G4 and I love my Model S.

AmpedRealtor | 10 juillet 2013

I'm not sure how a/c compressor noise can be deemed "embarrassing". It's the sound your car makes, why do you feel it a personal humiliation?

Carefree | 10 juillet 2013

Well, it is kind of embarrassing. When you show off your car and tell people that it is electric, everybody expects "SILENCE" Instead the compressor kicks in and people look at you with this weird and disappointed expression. Of course all that changes once you show them the acceleration but still - it would be so much nicer if that damn compressor was not as noisy.

terryd | 10 juillet 2013

I may be ordering one in a month hope this doesn't change my mind maybe a fix will come soon.

TomasT | 10 juillet 2013

@terryd I doubt it will change your mind... It's just an odd sound that makes people scratch their head. The experience with the car is too awesome for that to matter much. It's still quieter than any ICE vehicle. Also, that hum only lasts for a few minutes when the a/c is first turned on.
But hey, it's good that you know about it so you don't get any surprises.

AaronL | 10 juillet 2013

outside temp in Palm Springs was 114, car parked in community garage and I started the ac from my iphone. Worker knocked on my door and said something is really wrong with your car. I must admit it was loud in the garage. I also have a slight vibration in the steering column for a few minutes. Interestingly no loud noise or issue up to 95 degrees. Love the car, did I mention that I love the car.