The high-pitched whine during acceleration...

[scaesare]

I think we are talking about two different noises here. The balloon squeal only happens at max throttle or close to it, and i have only heard it on the performance Model S. The other noise is more of a drone, or a hum, at least in my experience.

Agreed. Balloon squeal has been present on my car since day one when I floor it... and it's similar to the magnetic resonance you can hear on other electric motor/inverter systems under load. Not abnormal, IMO.

The drone/hum/howl that I'm now experiencing is new after 16K miles, and is a constant above 67 or so MPH under "cruising power" (10-20kWh). It's gotten gradually louder, and sounds like a mechanical source (bearing, gear tooth wear, etc...). Other threads have discussed this issue also.

 

[mnx]

So I have a better idea why some complain about the noise and would like it fixed and others think it is no big deal. I had a MS60 loaner yesterday and it made the the balloon deflating noise as low as 60kW on the power meter, although not consistently. It frequently made the noise at 120kW. It also did it once or twice while under max regen. I think the noise was slightly louder as well. It was definitely more annoying than in my car. If that were my car I would've definitely appreciated a fix.

 

[JohnnyMac]

My P85 was silent under max acceleration for 2-3 months. Then the balloon squeal began. Now it occurs at a lower kW than it originally did. It most often occurs when there is more weight in the car - 4 adults. That is of course when the passengers also ask (with a befuddled look on their faces) "what is that squeal?" I maintain that it is not correct and needs a fix. In my case, it is both annoying as well as distracting, and frankly, it does not well represent the virtues of the car.

 

[jchangyy]

is it a whine or more of a hum? like halogen light buzzing / sodium parking lot lighting . This is what mine has when driving slow and using 'maintenance' throttle

I get that same "whine" between 30-40mph, maintaining an acceleration of 15-25kW. noise started ~8-9000 miles and worsened over 3-4 months. I'm at 12,200 miles now. will ask when I take it in for an annual.

 

[Mayhemm]

So I have a better idea why some complain about the noise and would like it fixed and others think it is no big deal. I had a MS60 loaner yesterday and it made the the balloon deflating noise as low as 60kW on the power meter, although not consistently. It frequently made the noise at 120kW. It also did it once or twice while under max regen. I think the noise was slightly louder as well. It was definitely more annoying than in my car. If that were my car I would've definitely appreciated a fix.

My P85 was silent under max acceleration for 2-3 months. Then the balloon squeal began. Now it occurs at a lower kW than it originally did. It most often occurs when there is more weight in the car - 4 adults. That is of course when the passengers also ask (with a befuddled look on their faces) "what is that squeal?" I maintain that it is not correct and needs a fix. In my case, it is both annoying as well as distracting, and frankly, it does not well represent the virtues of the car.

This is what concerns me the most about the noise; the inconsistency of it.
Some cars have the noise, others do not.
On some cars it is unobtrusive, on others it is annoying and embarrassing.
Some experience it when drawing a lot of power, others have it during low power draw.
For some it appears consistently, for others the behavior changes over time.

Personally, I hope Tesla beefs up their sound-deadening around the drivetrain, regardless of whether this is a "normal" sound or not. It's like an ICE manufacturer arguing against the use of a muffler. :redface:

 

[Stoneymonster]

I get that same "whine" between 30-40mph, maintaining an acceleration of 15-25kW. noise started ~8-9000 miles and worsened over 3-4 months. I'm at 12,200 miles now. will ask when I take it in for an annual.

Got mine back. "Normal".

 

[scaesare]

Got mine back. "Normal".

So that sounds like the drone/hum/whine phenomenon (not the high-current balloon squeal).

How did they fix it?

 

[Mayhemm]

So that sounds like the drone/hum/whine phenomenon (not the high-current balloon squeal).

How did they fix it?

I may be mistaking his meaning, but I think Stoneymonster is indicating that Tesla dismissed the sound as Normal and wouldn't correct it.

 

[scaesare]

I may be mistaking his meaning, but I think Stoneymonster is indicating that Tesla dismissed the sound as Normal and wouldn't correct it.

Ah, yes, I bet you are right.

:/

 

[Stoneymonster]

I may be mistaking his meaning, but I think Stoneymonster is indicating that Tesla dismissed the sound as Normal and wouldn't correct it.

Indeed. Just to be clear, my issue is the high pitched whine when drawing between 20 and 40 kW.

 

[Mayhemm]

Indeed. Just to be clear, my issue is the high pitched whine when drawing between 20 and 40 kW.

That's a little disheartening.

 

[Stoneymonster]

That's a little disheartening.

The service manager's exact words were: "It's the HV contacts making noise when drawing a high load." When I pushed back and said 20kW isn't a high load, he seemed to indicate any draw was technically high.

 

[jchangyy]

Sunnyvale service center also said noise might be normal and wants to monitor for any change

 

[WarpedOne]

The service manager's exact words were: "It's the HV contacts making noise when drawing a high load." When I pushed back and said 20kW isn't a high load, he seemed to indicate any draw was technically high.

High/not high doesn't really matter. What matters is that between 20 and 40kW the induced forces in frame are just enough to resonate or sing.
There really is no easy fix to this except completely redesigning the frame moving its own frequencies out of drive-train frequences (and away from its higher harmonics). More dampening would help but not fix this problem.
GenIII might be better in this regard. Maybe.

Remember those solders that must break step when going over the bridge? Exactly the same problem.

 

[niptuck]

2000 miles of fun driving (previously in a 2011 m3)- quiet and smooth. Love this friggin car. Heard the balloon deflating sound on hard acceleration when I took a p85+ for a test drive back in August. Asked the Tesla co-pilot about it and he said that it was normal and part of an EV. Didn't love it, but SO loved everything else. From day one with my p85+ no balloon/kazoo sound, even with very hard acceleration (flooring it to max acceleration and everything in between).....until tonight. First time I heard it. Didn't like it one bit. Was on hard acceleration and going from 65-80 once at higher speed. I couldn't replicate it later in that night after driving out and about. Will see if and when it happens again. Kind of strange that it would be silent for 2000 miles and then start.

 

[Mayhemm]

Kind of strange that it would be silent for 2000 miles and then start.

This is the salient point. Normal sounds caused by the physics of moving tons of power through the car, as WarpedOne describes, should always occur under the right conditions. That's what makes them normal.

As you've discovered, this noise does not fall under that definition of normal. Some cars have it rarely. Some have it often. Some don't have it at all. Thus, NOT normal.

Quote the physics at me all you want, but also explain this erratic behavior! A light doesn't only come on after the 1000th flick of the switch, and at varying brightness when it does; If everything is connected properly, the light comes on. Simple. Normal.

 

[SCW-Greg]

With most ICE, new cars have a break-in period for the engine. A longtime ago that break-in period was for many miles, 2,000+ miles if I remember correctly. These days it's much less. They use to ask you to try and vary speeds while driving (no cruise control). Now it's just avoiding high speeds.

You have to wonder if there is something similar needed for the Model S motor too. My car was the same, no noise, until around 1500 - 2000 miles. And like most us... giving lots of "accelerated" joy rides to friends during that time. Now I drive it much more conservatively, with only an occasional burst here and there.

And usually it's whines, occasionally it doesn't. 12,000+ miles later.

 

[scaesare]

This is the salient point. Normal sounds caused by the physics of moving tons of power through the car, as WarpedOne describes, should always occur under the right conditions. That's what makes them normal.

As you've discovered, this noise does not fall under that definition of normal. Some cars have it rarely. Some have it often. Some don't have it at all. Thus, NOT normal.

Quote the physics at me all you want, but also explain this erratic behavior! A light doesn't only come on after the 1000th flick of the switch, and at varying brightness when it does; If everything is connected properly, the light comes on. Simple. Normal.

Except the physics of materials is not a static thing. Inside that motor and inverter pair there are materials such as: steel, aluminum, copper, epoxy, rubber, fiberglass, grease, cooling fluids, plastic, etc... The materials are making up components such as casings, windings, bearings, electronics assemblies, cables, coolant piping, seals, lubrication surfaces, etc...

As conditions change, so to do the response of these materials to external stimulus. Many things can vary: temp, humidity, pressure, age, etc...

I can think of one very simple explanation: the epoxy in which the inverter power electronics or winding are encased[1] becomes more rigid over an extended aging period and components resonate differently than they did shortly after it was initially assembled.

There are a myriad of other reasons why things can show up later.


[1] Example only, I have no idea if this is really the case, or even if epoxy is used within the assemblies, although that is often the case for ruggedized electronics.

 

[Forty Creek]

Except the physics of materials is not a static thing. Inside that motor and inverter pair there are materials such as: steel, aluminum, copper, epoxy, rubber, fiberglass, grease, cooling fluids, plastic, etc... The materials are making up components such as casings, windings, bearings, electronics assemblies, cables, coolant piping, seals, lubrication surfaces, etc...

As conditions change, so to do the response of these materials to external stimulus. Many things can vary: temp, humidity, pressure, age, etc...

I can think of one very simple explanation: the epoxy in which the inverter power electronics or winding are encased[1] becomes more rigid over an extended aging period and components resonate differently than they did shortly after it was initially assembled.

There are a myriad of other reasons why things can show up later.


[1] Example only, I have no idea if this is really the case, or even if epoxy is used within the assemblies, although that is often the case for ruggedized electronics.

And whatever the reason, I'm betting that it isn't an easy or inexpensive 'fix'... or else Tesla would have been all over it. I recently car pooled with another Model S owner using my car. At one point I had to step on it a bit and the balloon squealed loud and clear. My passanger was obviously surprised and asked "what the heck was that?" His car does not make the sound.... yet.

 

[scaesare]

I'm going to side with the Tesla's stance that I've heard repeated here that the balloon squeal is "normal" (that is, within reasonable parameters for a high-current inverter/motor drive).

I've been around enough motors, inverters, and rectifier assemblies to know under high current it's not unusual at all, and there's nothing electrically/mechanically "wrong" with the car. Yes, there's some variation in cars, but that doesn't mean it falls outside of acceptable norms.

This is a "cosmetic issue", IMO...