Forums

Concerning Motor Noise

Concerning Motor Noise

I have noticed a noise that I believe is related to the motor. I have read about highway cabin noise, the high-pitched whine with acceleration and AC related noise, but the noise I am hearing is different. I searched the forums and found about six other users with reports of a similar noise at http://www.teslamotors.com/forum/forums/firmware-44. I addressed my concerns in that thread, but the thread was created to discuss software, so I decided to start a new thread to see if I can find some answers.

The noise typically occurs when driving faster than 30 or 40 MPH and definitely while I am on the highway at higher speeds (60 MPH). The noise becomes audible as soon as I push the accelerator and goes away as soon as I take my foot off the accelerator. It sounds like a low pitch humming noise or a buzzing noise and while it's hard to pinpoint, it sounds like it is coming from the back of the car.

I brought it in to my local service center and left it there for a day. They drove my car and other cars they had on hand. They noticed the sound in my car and not in the others. The best explanation they could offer me was that they thought it was normal, and perhaps it was part of the "break-in" of the car. They added that if it is actually an abnormal noise, the sound should get louder and louder over time. I'd rather not wait for a problem to get worse, which is why I have been searching the forums. One user in the aforementioned thread apparently had the same problem and had it "fixed" by a service center. But, the problem's explanation and the fix are still unclear.

I am not 100% sure, but I don't believe the sound was there when I first got the car in February of this year. I started noticing it a few weeks ago. Has anyone else noticed this? If so, is there an explanation and/or a fix?

Thanks in advance.

Xerogas | 19. Mai 2013

Do you have the AM radio on when this noise occurs? AM frequencies are very susceptible to interference from the electronics in the car. I know I get plenty of crossover noise whenever I have an AM station tuned in, so the noise is coming from the speakers in my case.

lightly | 19. Mai 2013

I have a similar problem except mine sounds like a high pitched electronic whine. . Again it only appends under moderate to heavy acceleration.

The sound comes from the driver side rear and It happens even if the radio is off or muted.

I asked at the service center and they said that it's normal. But I don't agree.

jbrowdy | 20. Mai 2013

Mine is not related to AM radio and it's not the high-pitched whine that has been associated with acceleration- although I do have that as well. This is a different noise.

cgiGuy | 20. Mai 2013

If your car does it and the others at the service center do not--they need to keep digging.

I haven't heard of, nor read in the "manual", anything about a break-in period.

Drive it like you stole it from day 1.

ichong | 20. Mai 2013

I have an S85 and took delivery in March. After about 1000 miles, I got upgraded to 4.3. The next day, I got upgraded to 4.4. At about the same time I started hearing the same noise that you describe - humming noised that started when I went above 65 and seemed to be coming from the back of the car. I spoke to a tesla service rep and they told me that they'd never heard of this problem before. After exchanging several voicemails to schedule a visit to the Meno service center, the noise went away. I can still hear a faint humming when I go about 65, but it's not as noticeable as before.

andex23 | 20. Mai 2013

I have the same sound however I don't believe it is linked to a software update sd I have had 3+ updates with the noise remaining. My last explanation was that it was the differential. I have 10k miles on the car and the noise has not gotten better or worse, most noticeable at freeway speeds. I do not have an answer for what it is but I do not think it is software issue.

truebeliever | 20. Mai 2013

Hmmm, low pitched humming noise coming from the back. It sounds like we may have the same noise. To me it sounds and behaves like gear noise from the transmission. It's quiet on deceleration and "float" but the moment there is power to the wheels.....Hmmm.
I only recently started to notice the sound (@6500 mi.). If it gets louder I'll have it checked out.

TeslaTap.com | 20. Mai 2013

This could be a pain to find. My Lexus had a wind noise problem that took them 2 years to solve (and was not retrofitted).

Is it possible your hearing is better than most? I'm sure many of us have loss a bit of the high-end, and the sound may be in all cars, but some of us can't hear it. Even the techs might not hear it.

I also have thick carpets on all the floors and the rear area. It might dampen the sound, but I don't remember any similar sound when I first got the MS and didn't have the carpets.

Lastly, it may be an audio system problem. Turn off the A/C and mute the audio. Have a passenger place their ear next to the door speaker and then next to the tweeter in the windshield pillar to see if they hear the sound from the amp. The amp might have a filtering problem and/or the motor electronics is not filtered enough and/or there is some kind of induction coupling of the frequencies.

Good luck! Anything you can do to isolate exactly where the sound is coming from will help the techs.

hfcolvin | 20. Mai 2013

I have a sound like that when accelerating and to me, best described, as a very much muffled ICE acceleration sound. It sounds like if you're standing outside and hear a car accelerating rapidly far in the distance. My sound kicks in at about 40 kW of acceleration and tapers off as I reach a cruising speed. Doesn't really bother me and I assume it's something to do with the motor spinning up.

jbrowdy | 20. Mai 2013

Thanks for the input. truebeliever and hfcolvin give good descriptions of what I am hearing. The noise persists with no AC and muted audio.

I have a feeling I will not find an easy answer, and while it probably shouldn't, it seems to bother me. It sounds almost like a bad muffler and I'm afraid it'll cramp my style when I'm trying to show the car off....

TeslaTap.com | 20. Mai 2013

I'd also try another MS to see if you hear the same sounds. From the responses of other MS owners, it doesn't seem normal.

If it is unique to your car, it could be as minor as some sound-isolation material that is not in place or a tiny void that lets the outside/motor noise in. That doesn't mean it will be easy to find, but worth trying to locate.

Michael39 | 20. Mai 2013

I am really getting pissed off at Tesla for not acknowledging this issue.

I have the same problem with my car. Someone on TMC described it as a sound like when you stretch a balloon nozzle and it squeals. That's exactly the way it sounds.

Tesla knows what the problem is. It existed in their demos cars during the amped up events. When asked about the squeal I was told it was because these were alpha cars and the problem would be fixed.

I believe the motor controller is going into oscillation during heavy acceleration. Mine did it several times today going to work. I almost stopped by Fremont service to demonstrate but didn't have time. Then it did it again going home for every heavy acceleration I did for about 20 minutes. Then it stopped. This problem started several thousand miles after I got the car.

This is not normal. Do not let Tesla BS you. I have not been able to pin point the conditions, such as high or low battery voltage (it does it at both). Air conditioning seems to not make a difference.

Tesla please acknowledge this problem and fix it.

aaronw2 | 20. Mai 2013

There is a soft whine in my car during heavy acceleration. According to a friend of mine who works at Tesla and is very familiar with the drivetrain it is due to the gears meshing. He said there's a trade-off between how quiet the gears are and how efficient they are using helical gears. The more teeth are engaged at any one time the quieter the gears but the greater the loss due to friction.

Michael39 | 20. Mai 2013

I agree that there is gear whine in the car. But if this problem was related to gear whine it would be there all the time and would change frequency with speed. This squeal I am referring to is abrupt, constant frequency and loud at high acceleration. And it sounds electronic, not mechanical.

Brian H | 21. Mai 2013

Electronic sounds are very hard to localize, because the waveforms are identical, and the input from each ear is lacking in identifiable "wiggles" for the brain to match up.

jbrowdy | 21. Mai 2013

Just to be clear - this post is not about the whine many people describe. This is the low, muffled noise that sounds like a buzzing or humming noise - almost like a bad muffler.

Mine seems to be getting louder. It really bothers me.

Michael39 | 21. Mai 2013

Brian H. I have been an electronics test engineer for 30 years. I've worked on high power electronics. The last was an HVAC system for a big rig that converts 12VDC to 300VDC at over a kilowatt to drive an air-conditioning compressor.

This noise the car makes is exactly the same noise that system made when it was unstable. It could result in the destruction of the power output stage.

I'm afraid that this could result in damage to the motor controller if allowed to continue too long. Then I could be stranded somewhere.

Today the car has not squealed on me. I'm beginning to suspect that it's temperature related.

GeekEV | 21. Mai 2013

@Michael39 - Impressive credentials. Certainly lends authority to your comments...

Brian H | 21. Mai 2013

Yes, if the car is sending out audible distress signals, it behooves you to pay heed and respond.

Velo1 | 21. Mai 2013

I may be able to help, as I am a professional acoustical engineer and Board Certified in Noise Control. First, I do not have either the low-muffled sound or the high-pitched sound described by @jbrowdy and a few others here, respectively. Second, without experiencing these events, I can only offer some educated-guess work and a few troubleshooting ideas from experience in the science of noise control. Third, as noted by someone else, noise is very challenging to find, especially when structureborne in its origin. Fourth, I can't think of a fourth, so here I go:

RE: Low-muffled noise:
Since @jbrowdy's car has this noise and other cars driven by the service center guys do not, then clearly this is not normal and is not part of the "break-in", IMO. If this noise was present from day 1, and didn't just appear one day out of the blue, then either there is a defective part or there was a poor installation/assembly during the car's build. If it is a noise that began well after delivery, then see my comment below on the high-pitched squeal. Sorry I cannot be more specific with advise, but really without proper acoustical measurement, both sound pressure level and vibration analysis, it is difficult to be more narrow with a response. FWIW, the most difficult aspect of noise control is locating the origin or root-cause. Once the root-cause is identified, as you might expect, mitigation is often straightforward. Clearly, this problem has a solution, based on the fact not every Model S has this noise. I would keep pressing the service center to find and fix it - or get some professional help. If they need to bring in a skilled expert in acoustics, I can probably locate and recommend a name of someone, but I need to know where you're located. Alternatively, you could visit the National Council for Acoustical Consultants at www.NCAC.com, and there is a place on their website to find a local consultant.

RE: The High-pitched Squeal:
If the high-pitched noise of concern was not present when the car was new, but then begins to arise after time or after several thousand miles; then it is undoubtedly due to something failing (I know that states the obvious).

What I would recommend for the high-pitched squeal @Micheal39 describes is to have TM see if the motor controller is (1) failing or failed, and/or (2) it has worked itself loose due to road vibration after a few thousand miles. @Micheal, I think your suspicion of an oscillation in the motor makes sense, from my experience. Again, the same website listed above might provide the assistance TM needs to fix these noise-related concerns.

We all know from many threads about bad 12V batteries, which I had myself, that in my opinion, TM is most likely relying upon their suppliers for quality control, and TM needs to hold them accountable (zero defects). After all, replacing all these 12V batteries, and other components like door handles, charge ports, etc., has to be costing them money. I frankly do not know how TM controls quality, so these are just my suspicions, too.

Oh yeah, "fourth", please, please ensure this thread is private. good luck, keep us informed with updates, too. And for Brian H - I am at an airport gate waiting to board my plane, so in advance I apologize for my spelling and sentence structure, as my iPhone has this annoying auto-correct function that inserts what they want and not always what I meant to say.

jbrowdy | 21. Mai 2013

Great stuff, Velo.

I'm in St. Louis, MO.

Safe travels ;)

Brian H | 21. Mai 2013

advice

Auto-Error

If something is making unwanted noise, some part or parts are wearing out or coming loose or coming apart at an accelerated pace.

Energize | 21. Mai 2013

i too am hearing such a noise

jbrowdy | 22. Mai 2013

Another analogy I would use is it sounds like a swarm of bees - but the pitch changes depending on how hard you push the accelerator.

ITSELE | 23. Mai 2013

I have the "hum" noise. I disagree with jbrowdy in that the PITCH changes only with the speed of the car. The AMPLITUDE or loudness of the hum increases with more pressure on accelerator. I would describe the sound more like what you hear when a monster truck (loud tires) is driving next to you (although not nearly that loud). It's best heard with the A/C and Radio off. I would also add that the noise occurs for me between 60 and 80 mph. I had my first Tesla Service appointment and demonstrated the noise to the lead technician (Nicholas in Phoenix). He was very interested and we went on a ride together. He listened closely to the back of the car. He had not noticed that particular hum before. My car is only 3 weeks old and the sound has probably been there since day 1. One thing I did was take out the rear "cover" (not the privacy cover) under the hatch to have that big well available for "stuff." Nicholas recommended reinstalling the cover. The cover is pretty thick and after reinstalling it, the noise level has gone down by 50% and is not nearly as noticeable. There is very little insulation for sound in the back and I believe more than likely it is a "normal" sound which could possibly be from the transmission or even the tires (I have 19" wheels in a 60 kWh MS). I would recommend reinstalling the rear hatch well cover. I would bet that the "jump seats" would help insulate the noise as well as the privacy cover. In a normal ICE car you would never hear a hum like this as the engine/transmission/road noise would drown it out and there is probably more insulation in an ICE car. For now I am going to monitor the noise per Tesla Service recommendation.

jbrowdy | 25. Mai 2013

Itsele,
You may be correct. It may be a normal noise, and it is very possible I never noticed it before. If I had assurance that it is normal, I could live with it. It's not very loud. I just don't like the thought that something is possible abnormal.

I brought my car in twice for it, and then escalated the issue by calling Tesla. They want me to bring my car in again for the local service center to communicate with engineers. It's a pain to keep bringing the car in, so I am not sure how quickly I'll bring it in. If anyone has any additional information, please feel free to share.

Thanks.

Mark K | 25. Mai 2013

Based on the descriptions from those that are hearing it, here is my guess:

Summary

Resonant vibration of loose magnetic coil windings under certain power demands.

Background

The power system contains inductors. These are windings of wire around a magnetic core - think of the wire around the nail experiment when you were a kid.

The power inverter (controls flow of power from the battery to the motor) has inductors in it.

The motor stator windings are also effectively the same class of structure. They are wire coils.

What happens to windings as you pulse current through them is that the magnetic field exerts a force on the coil each time you turn the current on and off.

Usually, these coils are laminated tight by winding tension and adhesives, so they don't move. Sometimes however, they can become loose through damage or defects.

When they are loose, they can jiggle when jolted by the surge of current through them. If that happens you can hear them buzz at a frequency related to how fast they are pulsed.

To increase acceleration, your Model S pulses the power through these coils at a tighter spacing (frequency and/or pulse width).

When the frequency matches the natural resonate frequency of the mechanical structure of those loose magnetic coils, they jiggle the most and sound the loudest.

Other things like the reduction can also show resonant vibration as a function of rpm. But you are hearing this on acceleration, not just at certs, but Based on when you hear this, I think this is the most likely reason.

The fix is to replace the loose coil structure, or apply damping adhesive to stops its vibration.

Mark K | 25. Mai 2013

Accidentally hit send before finishing -

But you are hearing this specifically on acceleration, when current pulses are strongest, not just at a particular rpm when you are cruising. That's why pure mechanical vibration is less likely.

Based on when you hear this, I think loose coil windings are the most likely reason.

The fix is to replace the loose coil structure (inverter inductor or motor winding), or to apply damping adhesive to it to stop the vibration.

Mark K | 25. Mai 2013

Missed this too -

"Other things like the reduction gear can also show resonant vibration as a function of rpm, but I think this is less likely."

Mark K | 25. Mai 2013

Here's a coherently merged version (edit would be cool) -

Based on the descriptions from those that are hearing this noise, here is my guess:

Summary

Resonant vibration of loose magnetic coil windings under certain power demands.

Background

The power system contains inductors. These are windings of wire around a magnetic core - think of the wire around the nail experiment when you were a kid.

The power inverter (controls flow of power from the battery to the motor) has inductors in it.

The motor stator windings are also effectively the same class of structure. They are wire coils.

What happens to windings as you pulse current through them is that the magnetic field exerts a force on the coil each time you turn the current on and off.

Usually, these coils are laminated tight by winding tension and adhesives, so they don't move. Sometimes however, they can become loose through damage or defects.

When they are loose, they can jiggle when jolted by the surge of current through them. If that happens you can hear them buzz at a frequency related to how fast they are pulsed.

To increase acceleration, your Model S pulses the power through these coils at a tighter spacing (frequency and/or pulse width).

When the frequency matches the natural resonant frequency of the mechanical structure of those loose magnetic coils, they jiggle the most and sound the loudest.

Other things like the reduction gear can also show resonant vibration as a function of rpm, but this is less likely the cause since you are hearing this specifically on acceleration, when current pulses are strongest, not just at a particular rpm when you are cruising. That's why pure mechanical vibration is less likely.

Based on when you hear this, I think loose coil windings are the most likely reason.

The fix is to replace the loose coil structure (inverter inductor or motor winding), or to apply damping adhesive to the coil lamination layers to stop the vibration.

Mark K | 25. Mai 2013

I've seen this effect on power subsystems we be built, which is the basis for my intuition and comment.

Of course, it could also be something dumb like a loose screw too.

The key clue though, was that it followed the demand for current. That's why I suspect a coil.

If I'm right, it's totally possible to restore it to perfect condition. Beyond remedying the errant coil, there are also firmware noise snubbing measures possible, but the drive pulse shaping must really be governed by efficiency and horsepower optimizations, not noise management. I'm guessing they'd remedy the coil itself.

The guys in Freemont I'm sure are investigating this now. They'd be able to quickly affirm or dismiss each theory by swapping out subsystems like inverters, motor, etc., on a car that is known to exhibit the problem.

They'll find it. You don't work this hard to make the car so smooth and quiet, and then let something like this go. Don't worry, these are very smart guys.

GeekEV | 26. Mai 2013

@Michael39 - I just started experiencing the balloon nozzle noise you described this morning. That's a very accurate description of the sound. Like others have described, it only happens under full throttle. I have an S60. I've got an email out to my service advisor with a link to this thread to see what he says.

Michael39 | 26. Mai 2013

@geekEV,
I've been racking my brain for a scientific way to prove that this problem is uncontrolled oscillation of the drive electronics caused by either noise or the drive system electronics not working correctly.

What I think you will find is that your acceleration goes into the toilet and the car is much slower. This can be proved by doing an acceleration run and recording the accelerometer readings. I can already tell that that car feels sluggish when I hear the squeal.

A bit of technical background on the drive system. The Model S has an three phase synchronous AC motor driven by three banks of IGBT devices in turn driven by a sophisticated controller. The controller monitors speed, current, voltage and the traction control. This is all done by a microcomputer. OK, now when the car is told to move, the controller applies this three phase power to the motor. The speed of the motor is controlled by something call slip which is the phase difference between the three phases. This power is a smooth sine wave that makes no acoustical noise. But, when you hear the squeal, you are hearing uncontrolled power being applied to the motor that is more of a square wave which has lots of harmonics. This is the noise that you hear coming from the back. It could be one phase or all three phases oscillating.

ajamison | 26. Mai 2013

Michael39 I am no scientists to so please forgive me if this sounds horribly wrong.

Could you not take the energy data for the last time you had this issue and couple it with other data possibly run an audio or video recorder while the sound happens and compile all of this data into some kind of diagnostic package for the service center to try and diagnose the problem?

It seems to me that if its an issue as you mentioned the power output would not be where it should be for the type of acceleration your doing.

Again not a scientist so please excuse this if it sounds wrong

ajamison | 26. Mai 2013

Worse case scenario I would insist that the service center look over the drive train with a fine tooth comb to try and narrow it down.

Mark K | 26. Mai 2013

Michael39 -

Let 's see if we can establish some assumptions -

Whether the power drivers are bipolar linear transistors or switched mode FET's, for you to hear the acoustic pressure wave, something is physically moving, which in this case has to be a coil of some sort.

Without an electromagnetic force, the other circuit elements (like the silicon components) experience no mechanical forces that can produce acoustic energy. (Minor exception is pure electric fields on piezoelectric elements - but this is generally very small on ceramic capacitors).

So I think your hypothesis works like this:

A. Parts OK, but Control Loop Unstable

The wave shape of the motor drive current current goes anomalous, so motor coils that are perfectly fine are excited in an unusual manner, resulting in the different sound. That's possible.

The hypothesis I posited is:

B. Control Loop OK, but Parts Delaminated

The drive current waveforms are OK, but some coil, perhaps an inductor in the drive electronics, or perhaps a motor winding, is not securely laminated. When you are at the right RPM and ask for a lot of drive current (whether by FET pulse width or by IGBT voltage), the combination excites the loose coil mechanically, effectively forming a tweeter. The "balloon squeaking sound" sounds very similar to this.

For A to be true, the control loop would have reduced power output when you hear the squeaking. If that's the case, it strongly points to your hypothesis.

But I did not see any complaints about loss of power. If thrust is still normal, then to me, it points more to B.

Would be very helpful if any drivers online who've heard the sound can comment on whether thrust dropped out, or was normal when the squeaking occurred.

Interesting puzzle.

Brian H | 26. Mai 2013

Is the car suffering from gas? >;p

Michael39 | 26. Mai 2013

@Mark K
I totally agree with you to hear sound something must be moving. My theory is either the motor windings or other magnetics in the controller or even the interconnecting wires can vibrate with these very large currents.

And I think your theory A is the correct one.

Thanks for your input.

Robert22 | 26. Mai 2013

In regard to the high-pitched squeal heard when you mash the accelerator:

When I received my car in December the noise was immediately apparent. I had a discussion about it with my delivery specialist. He said it was present on every car and was well known to the engineers as the Tesla "chirp". I realized immediately this was going to cause an issue for some future owners because it sounds unrefined and in need of correction. I got the impression after our discussion that if there was a way to prevent this sound, it would have been implemented.

Mark K | 26. Mai 2013

Robert22 - there are many sounds as the motor revs up - are you sure your chirp is the same as what some have described here?

It's normal to hear some sound emitted from the motor as the magnetic flux changes and exerts mechanical force on the windings. But many described a louder sound that even the techs seem to have considered unusual.

There's AC motor whine, and then there's air squealing out of a balloon. I've not myself heard what was described by those complaining in this thread. When I hammered the P85 it gave out a whine, but did not squeal unpleasantly.

The quality described here that gives pause is the discontinuity - the sounds that kicks in between 60-80. Drive system faint chirp that is progressive with rpm on acceleration is not unexpected. But a loud discontinuity does not seem right.

Perceptual stuff like this is always tough. The folks who've complained should definitely chime in so we can get a lock on what's common vs. atypical.

If we take the concerns at face value, something different is happeniing on some cars.

GeekEV | 26. Mai 2013

@Robert22 - I know the high pitched whine you're talking about. My LEAF does it too - it's inherent in electric propulsion. This is very different. The description of blowing up a balloon and letter the air squeak out through the nozzle (we've all done that as kids, right?) is spot on. The moment I first heard it I immediately flashed back to this thread because that's exactly what it sounded like. This is a new sound I hadn't heard before.

Brian H | 26. Mai 2013

But if some have it, and some don't? Sense makes it not.

David70 | 27. Mai 2013

Except that if it's there and high pitched, I probably wouldn't hear. I've had hard drives that whined. Others complained about the noise, and I would have to reply "What noise?"

Mark K | 27. Mai 2013

GeekEV - Could you discern any loss of thrust when the sound started, or did it accelerate normally?

GeekEV | 27. Mai 2013

@Mark K - I've had limited opportunities to test it on the streets around here, but did not pick up on any discernible loss of power.

@David70 - It's not that high pitched. I think just about anyone would be able to hear it. It really does sound just like the sound a balloon makes when you blow it up and pull the nozzle taught then let the air escape...

Robert22 | 27. Mai 2013

@Mark K-

The OP referred to a "low pitched humming or buzzing noise" that starts after 30-40 mph. I am NOT referring to this sound that remains of undetermined origin. I'm referring to a separate second sound that is being described above as a high-pitched sound, like "air being squeaked out of a balloon". I've heard this on my non-performance car as well as two brand new Performance loaners. Three cars built 5 months apart that make the same sound on hard acceleration at about the same speed (~60mph) that has been called normal by Tesla. If this is a fault in the motor or drive train electronics, unlikely given the pervasive presence of the sound, than it affects all or most of the fleet.

Mark K | 27. Mai 2013

GeekEV - that's what I expected. I doubt the control loop is messed up, since that would beget bigger problems.

A chunky sized inductor has a mechanical structure that can vibrate with the same sort of spectrum. I've heard this same type of sound during power supply debugging.

I'm thinking it's in the inverter, from a batch of inductors with lamination/winding imperfections.

It could have escaped Tesla QA because it's a subtle flaw. Electrically, the part does its job, so you wouldn't see it fail functional test. It's just audibly noisy under certain conditions. That's not something you ordinarily test for.

Could be a motor coil too, but those are wound in-house so TM has more control over quality.

Lots of potential causes, but that's my hunch.

Mark K | 27. Mai 2013

Robert22 - Hmmm.

Well if they all have it, that certainly points to something intrinsic to the design. Which would likely just be vibrations of the motor coils themselves under heavy hits of current.

This is again a murky perceptual thing. Others can chime in if they've always heard the balloon squeak sound on hard acceleration or if there's something different from what they normally hear.

Robert - would you say it was loud enough to sound broken, or just noticeable?

Be aware folks, that if it is just the motor coils, a possible explanation might be that a few might be wound with a subtle looseness, so you'd all hear the same character of sound, but some cars would be quite a bit louder than others.

To settle this, you really need to make accurate recordings under the same conditions, and then compare them on a spectrum analyzer. A power Spectral Density map would tell you definitively.

Anyone who thinks theirs is unusually load could volunteer it for their service rep to get a recording.

Or an enterprising gang of a few Model S owners could make some recordings with the same IPhone in the same spot on a few cars, under consistent test conditions. To be useful, one in the group would have to be discernibly louder than the others.

You could email that to Fremont to help them figure it out.

nickjhowe | 27. Mai 2013

Way back when the cars were first released in June of last year the early speculation was that it was the inverter that makes the squealing noise. IIRC this was confirmed by a TM engineer, but experience has shown that verbal statements like that aren't worth the paper they are written on.

Pages