It's that time again - embarrassing loud AC compressor

[S4Life]

Wow, glad I found this thread as I too thought a fan went bad. I was out the other day and it was so loud it was drowning out huge diesels sitting next to me at a light. I am going to schedule a SC visit to get the TSB applied and a rattle I have in the A pillar or pano that is driving me nuts.

 

[Martini]

In the older thread on A/C noise, there were some who were convinced the noise was caused by vibration of the compressor (or hoses?) against the frame and not the compressor itself. This might explain why a new bracket is the "cure".

There is something definitely amplifying the noise, but the "buzzing" you hear is definitely the standard noise made by a variable speed scroll compressor at high RPM. There are several YouTube videos that demonstrate the noise. It's usually masked by a giant fan in home A/C units. When the compressor needs to spin up at that RPM, little you do will be able to silence it completely. Good to hear the blanket and mounting bracket dampens the noise a bit.

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You don't specify which Prius you have, but 2004-2011 models all used a Denso ES18 compressor, rated at 4500W power consumption at max speed. My observation is that the Tesla uses far less power when the compressor is going at full speed, although I don't have the specs on the compressor used (anyone happen to have a reference?). My guess is that they engineered for the best power consumption. The Prius can always burn gas to supply power as necessary, so that isn't as much of an issue compared to Model S.

 

[AnOutsider]

Well, it doesn't sound like pressurized air releasing because it's a periodic squeak that is constantly there when the A/C is running and slows-down to a stop when spinning-down or speeds-up when spinning-up. It is, as you say, the most apparent when spinning-down. I've heard the same thing on another loaner car (the one I have now), but plenty of other cars do not have this annoyance. So, you're saying that your squeak went away? Mine is over a year old and 25k miles and it's only gotten worse. And it gets worse each time they "fix" it. The service centers on the San Francisco peninsula are located on such busy roads (El Camino in Menlo Park and Palo Alto, US 101 in Burlingame) that they can't hear any noise from the cars. Not sure how they can diagnose anything noisy/rattly.

I've had my car for 30k miles now. Summer is just coming on, and I've resisted using the AC much because I like the silent cruising with the windows down. The day I recorded that video, I DID use the AC, but did not hear squeaking as it spooled down.

 

[Mr D]

Just took delivery of my MS last week and noticed a bit of vibration on the steering wheel while on the highway. Arranged for the SC to have a look and also asked about the AC noise. In addition to the tire re-alignment, they proactively installed the acoustic blanket and new bracket. It's made a big difference in the noise.

 

[gg_got_a_tesla]

Just took delivery of my MS last week and noticed a bit of vibration on the steering wheel while on the highway. Arranged for the SC to have a look and also asked about the AC noise. In addition to the tire re-alignment, they proactively installed the acoustic blanket and new bracket. It's made a big difference in the noise.

Surprised that Tesla's not installing the acoustic blanket and bracket at the factory already for new cars...

Waiting for firmware v6.0 to be out to justify a visit to the service center. Will get this TSB, armor plate, defog vents retrofit (for the next winter ) and maybe tire rotation done along with the firmware update. Range mode it'll have to be till then.

 

[EarlyAdopter]

I finally got a chance to put the new A/C compressor blanket and bracket to the test yesterday after the car sat out in the sun in 80F weather.

Before the fix my compressor sounded very much like the video posted above - high pitch scroll compressor buzz/whine plus a deep bass note like a cargo helicopter.

Now it's about 1/10 the noise level. It's quieter than the air intake fans on full. Ahhhhh... bliss.

 

[iKhalid]

Anyone having the noise with a model s built in 2014?

 

[rogerkang]

FlasherZ I have a 2010 Prius. It's not only stronger but the air blows better than the Tesla as well. And it's super quiet. I will ask for the fix next time I'm at the SC. Seems like the way to go. But yes, the AC has negligible effect on the Model S' range compared to the heater. I've been averaging 250-280Wh/mi here in NJ with the AC on all of the time. I guess it is super efficient!

 

[scaesare]

I point out when comparing A/C systems to other vehicles, they aren't also built to provide cooling for a 1,500 lb mass of battery pack.

 

[jerry33]

I point out when comparing A/C systems to other vehicles, they aren't also built to provide cooling for a 1,500 lb mass of battery pack.

Good point.

Besides starting a higher temperature setting, I've found that if it's loud turning the A/C off and then on quiets it right down. (The noise happens on my car when I don't set the temperature high enough to start.)

 

[andydoty]

Anyone having the noise with a model s built in 2014?

As I don't know what the compressor sounded line in the previous Model S's, I have no point of comparison. However, yes, there is a noticeable compressor sound coming from under the car. The only thing I've noticed is that it doesn't last very long. I can also hear a slight hum when I'm in the car (you can feel it too). It's completely tolerable though. I would consider it pretty quiet in comparison to the ICE compressors.

Now I'm in IT so technology piques my curiosity. It was hot in the car yesterday (around 105) and I turned the A/C on while it was plugged in. Heard the compressor and the fans (the fans seem louder then the compressor). I noticed that there are louvers in the nose that open and close depending on the A/C load. Did believe it until I saw it for myself. They close to cut down drag. I've noticed that they vent into the wheel wells.

A little thing I've learned about vehicle A/C systems is the size. The average small home will have anywhere from 3-4 tons of cooling (a ton is 12000 BTUs). Most cars have 3 tons of cooling and are much smaller. So, why such a powerful A/C for a little space. A friend in the industry alluded to the time it takes to lower the temperature of the cabin as opposed to cooling an entire home. Think of the cooling power needed to lower the temperature of a cabin in excess of 100 degrees to a comfortable 70 degrees. Not very long is it?

Now go outside and look at the condenser for most home central air conditioning systems. The one in the Tesla is about the size of a small loaf of bread. Amazing? I think so...

 

[AnOutsider]

I point out when comparing A/C systems to other vehicles, they aren't also built to provide cooling for a 1,500 lb mass of battery pack.

That's very well, but Tesla knew that going in right? They knew the AC had multiple functions to perform and should have specced the system to do so IMO while keeping all aspects in mind (including sound). Saying "oh, but it does more than just any normal AC in a car" doesn't make anything better for me.

 

[SarahsDad]

Yep mine's loud too. This is outside in a quiet parking lot - when I'm pre-cooling my car like this I could find it with my eyes closed from 20 cars away just by walking toward the sound. Need headphones to hear the higher pitches.

 

[Ugliest1]

From my invoice:
<snipped>
Go forth and get your jet turbines silenced!

Thanks @EA for posting this. I'm on vacation in Palm Springs at the moment, and the car's AC noise is quite annoying (it's not used to this desert heat - and who booked holidays in PS starting in June anyway!! ). I stopped into the Cathedral City service centre this morning to ask if anything could be done but was told there were no mandatory SBs for my VIN. Didn't sound like anything would be offered. Aha! Armed with @EA knowledge, I asked about SB-#-whatever. Yes they could do that, so booked for tomorrow. I'll be able to get a loaner as well so our vacation plans carry on almost as though there were never a problem.

Since our vacation place doesn't have any electrical plugs outside at all near the parking area, the SC's 3 24/7 chargers are also very handy. Hope there's a noticeable difference with the "fix" tomorrow.

 

[LuckyLuke]

Yep mine's loud too. This is outside in a quiet parking lot - when I'm pre-cooling my car like this I could find it with my eyes closed from 20 cars away just by walking toward the sound. Need headphones to hear the higher pitches.

Mine (october 2013 produced) sounds EXACTLY like that video.
Temps peaked at 32C/90F here today, with lots of sun.
TSB noted on my to-ask list, thanks.

 

[mibaro2]

The way I have handled this is simply to put the car into Eco mode. It take slightly longer to cool the car down, but if your pre-cooling that's not a big issue. The fan is noticeably quieter when in Eco mode.

WOW... I have always had my car in Eco mode since I received it 2 months ago. I figured it was a safe bet when starting out as a newbie.
However, in Eco mode, I think the A/C is loud...I would hate to hear what it sounds like in normal mode.
:scared:
If it is quiter in Eco mode, I can understand why people complain about the noise since they probably have it in Normal mode.

 

[Canuck]

Thanks @EA for posting this. I'm on vacation in Palm Springs at the moment, and the car's AC noise is quite annoying (it's not used to this desert heat - and who booked holidays in PS starting in June anyway!! ). I stopped into the Cathedral City service centre this morning to ask if anything could be done but was told there were no mandatory SBs for my VIN. Didn't sound like anything would be offered. Aha! Armed with @EA knowledge, I asked about SB-#-whatever. Yes they could do that, so booked for tomorrow. I'll be able to get a loaner as well so our vacation plans carry on almost as though there were never a problem.

Since our vacation place doesn't have any electrical plugs outside at all near the parking area, the SC's 3 24/7 chargers are also very handy. Hope there's a noticeable difference with the "fix" tomorrow.

Ha! I doubt they've ever had to do this service at the Vancouver service centre. Using air on high will freeze us out except for maybe one or two weeks per year. But I just printed EarlyAdopter's service invoice since my car has to go in for other warranty work and I want to get it done for my trip down to California this summer.

 

[scaesare]

That's very well, but Tesla knew that going in right? They knew the AC had multiple functions to perform and should have specced the system to do so IMO while keeping all aspects in mind (including sound). Saying "oh, but it does more than just any normal AC in a car" doesn't make anything better for me.

I'm not stating what it should "do" for anybody in particular.

What I am stating is that drawing comparisons of the same or similar units in other cars isn't an apples-to-apples comparison.

 

[rkruff]

Is it just me or does 5.9+ software change the way the compressor works. It sounds like it only goes to ~80% unless you get over about 15-20mph, when it kicks into full power mode.

Still it is loud, but compressing a gas is loud any way you do it. It's better than an embarrassingly hot car IMO.

I just shut climate control off and then immediately turn it back on...that normally resolves it. The service center in Van Nuys installed an insulating blanket over the motor and that helped quite a bit as well.

 

[pete8314]

I just shut climate control off and then immediately turn it back on...that normally resolves it. The service center in Van Nuys installed an insulating blanket over the motor and that helped quite a bit as well.

I've done that a few times as well, and it does work, which kinda make me think that the software isn't behaving right. The AC does often seem to have a mind of its own.