High pitched noise from drive unit

[Sloopy]

I have owned a 3 RWD for a year. Since i was thinking about trading it in for a 3 AWD, I took a test drive today. My 3 has a pleasant whir at all speeds, but while driving the AWD, I noticed a high-pitched whine at various speeds and during regenerative braking. I asked the salesperson who was in the car with me about it. At first, he sort of claimed he couldn't hear it. Then, after a while, he admitted he could hear it and questioned whether it was that particular 3 making the noise. Then, as I drove around more, he said he was noticing it more since I had drawn his attention to it.
I do have good hearing, but higher-pitched sounds naturally cut through all other sounds and so they are more audible. Honestly, I'm not sure I could accept it, esp. after having been driving my current 3 which is much quieter. I will test drive another 3 to see if it's any better, but I hope that I get a salesperson who could offer better information.
One thing he did bring up as a possibility and that is that the sound might be coming from only the rear wheels in the RWD in which case it's harder to hear.
I'm curious to find out from you all....are your vehicles AWD or RWD?

 

[5_+JqckQttqck]

My 3LR RWD does the whirl on accel and decel; I love it - doesn't bother me. However, a loner named Orea from the Mississauga SC had a much louder whirl/ringing when flooring it from a stop.

I guess not all drive units are made equal. I believe there's a thread out there on how they classify the Performance motors after QA tests. The ones able to put out the require HPs is diverted to the P line while everything else goes to the regular line. Any truth to this?

 

[Dante]

Feel the need to revive this thread. After reading it, have to clarify: there is a “pleasant” whine, which is always there in both of the 3’s I have. There is also a more high pitched painful squeak/whine that is intermittently associated with regen, moderate speeds or high speeds. I haven’t had any service advisor actually listen to it, but I did ask months ago and was told (without anyone listening/checking) that this was within normal spec for cars once they hit 20-30k. Not sure if that’s true or BS. My noise showed up right after the car was in service for a week. Also coincided with the “range upgrade” update. So hard to know if the software caused it or something that happened while it was in service (or neither of the above and just coincidence). Goes from not there, to barely noticeable, to intolerable. I can’t believe this is normal. Not sure if it’s worth trying to get someone from service to listen to it. Filmed a few videos when it was at its worse, but it’s barely noticeable in the playback video.

 

[polyphonic54]

Yes, exactly. The motor whine is fun. The 'morse code' squeak is painful. Easy to hear in the car, but harder to record. I loaded it up in a spectral analyzer a while back and I think it was an octave, around 4khz and 8khz. I get it mostly in the 45 mph range, otherwise it's gone.

Preconditioning on the way to superchargers this past summer was a similar annoying sound, but sustained. These have been features of our car since we got it, but it's been impossible to convince Tesla there's anything wrong.

 

[RichGault]

So. I came upon this site today because of my motors on my Model S P90DL are extremely loud. I have always thought they were loud but never really questioned it until yesterday when I took it in for service to replace a cracked windshield and they gave me a loaner car. The loaner car is a rear-wheel-drive Model S and it is so quiet compared to my car. I am going to ask them to look at it and will update you guys on my outcome as soon as I know more.

 

[SigNC]

the tones of the motor are completely different when on route warming is running if that wasn't mentioned already, especially from the front motor.

 

[merito]

I downloaded the free "Sonic Tone Generator" app on my phone. If I set it to 8KHz and set the volume of the phone at 20%, it exactly reproduces the sound I hear when under hard acceleration on my Model 3 performance.

Anyone else agree?

 

[Vaillant]

One thought, for older Model 3 cars, is that if you are trying to dampen sound coming from the rear, you could cover the open mesh grate that’s between the rear passenger window shelf and the trunk. On the new Model 3s, they’ve covered that up from the factory, which is probably one of the reasons the 2020 model is quieter. You could do a test where you tape something over the opening and see if it helps.

Good luck!

 

[eclypse80]

Tesla service added some sound dampening to my trunk and under my back seats for me after my original complaint and it's been a lot more bearable since.

Is there any chance you have pictures of the dampening that they did. Tesla didn't offer anything when I brought my 2018 Model 3 (LR RWD) in for service earlier this month and I'd be wondering if this is something I can just do myself instead. The noise is a bit unbearable since most of my commute to work is in the 35-45mph speed range where it's most prominent.

 

[Tony_YYZ]

Is there any chance you have pictures of the dampening that they did. Tesla didn't offer anything when I brought my 2018 Model 3 (LR RWD) in for service earlier this month and I'd be wondering if this is something I can just do myself instead. The noise is a bit unbearable since most of my commute to work is in the 35-45mph speed range where it's most prominent.

Unfortunately I don't. I installed an upper trunk liner myself this past summer and it covers up all the sound dampening materials. They had used dynamat to cover up the grill from the trunk to the cabin and some type of thick tape in other various areas.

I was among the first to bring the issue to their attention and they did what they could to help but now, after many engineering reviews they have put a policy in place to say it's normal and they won't spend any time trying to "fix" it.

 

[Bubbatech]

Inverters generate a high pitched sound because of the switching action of the FETs (other manufacturers use IGBTs), which is one of the reasons why they are embedded in gel. Some people with a higher hearing range might hear that whine or its harmonic. When I was younger, I could hear ultrasonic alarm systems and other things that other people could not. I would complain about it, and people acted like I was nuts. They couldn’t hear it. You could be like I was then. So the service people may not be able to hear it like you can.

 

[Tony_YYZ]

Inverters generate a high pitched sound because of the switching action of the FETs (other manufacturers use IGBTs), which is one of the reasons why they are embedded in gel. Some people with a higher hearing range might hear that whine or its harmonic. When I was younger, I could hear ultrasonic alarm systems and other things that other people could not. I would complain about it, and people acted like I was nuts. They couldn’t hear it. You could be like I was then. So the service people may not be able to hear it like you can.

The service techs measure the sound using Tascam sound recorders. They can definitely listen for it but the end result is the same. "working as intended"

 

[M109Rider]

Inverters generate a high pitched sound because of the switching action of the FETs (other manufacturers use IGBTs), which is one of the reasons why they are embedded in gel. Some people with a higher hearing range might hear that whine or its harmonic. When I was younger, I could hear ultrasonic alarm systems and other things that other people could not. I would complain about it, and people acted like I was nuts. They couldn’t hear it. You could be like I was then. So the service people may not be able to hear it like you can.

Thanks for clearing that up. I’ve been wondering what the whine was specifically from. I thought it was the stater.
Now I know otherwise.

Question:
Any idea why one set of fets would have (more / louder / or a different frequency), whine than another set of fets while switching. ?

Does the variation mean anything significant?

Thanks in advance.

 

[Bubbatech]

Thanks for clearing that up. I’ve been wondering what the whine was specifically from. I thought it was the stater.
Now I know otherwise.

Question:
Any idea why one set of fets would have (more / louder / or a different frequency), whine than another set of fets while switching. ?

Does the variation mean anything significant?

Thanks in advance.

I don’t know enough about the circuitry to know where variation might be. I can speculate that differences in assembly or part tolerances could contribute to variations in noise. You can hear the same things in hybrid cars as well. My Prius had a prominent whine that could be heard outside the car. I hear nothing in my Tesla. However, at 61, my high end hearing has declined to about 8000hz.

 

[phigment]

I managed to capture the sound on a spectrum analyzer app on my phone. What I heard was between 3kHz-5kHz

 

[Bubbatech]

Not knowing the primary switching frequency, one cannot determine if you are heaing a harmonic or the fundamental. My guess would be the former. If i interpret the spectrum display correctly, it looks like a very weak set of narrow frequency bands in the range you mention. I’m not sure that isnt an artifact, given the way the lines are sloping.

 

[phigment]

Not knowing the primary switching frequency, one cannot determine if you are heaing a harmonic or the fundamental. My guess would be the former. If i interpret the spectrum display correctly, it looks like a very weak set of narrow frequency bands in the range you mention. I’m not sure that isnt an artifact, given the way the lines are sloping.

The slope is due to the change in frequency. The sound is shifting as the regen kicks in, or if I keep the throttle at a constant or light acceleration. While it does show up weak it is very noticable to me. Percpetion is very much relative to surroundings. Since there is not much happening in that frequency band it stands out quite a bit.

I've used this app to pinpoint sounds in my Zuba heat pump as well. I kept insisting that there was a sound around 200Hz, it was a good 30-40db lounder than surrounding sounds. They finally came in and agreed that the blower was unbalanced. They replaced it and all is blissful now.

 

[CharleyBC]

When I was younger, I could hear ultrasonic alarm systems and other things that other people could not.

When I worked in a big chain drug store in my high school years, I could hear the ultrasonic alarm system. The manager thought I was making it up, until he tested me one day by turning it on and off. After a while, he would simply ask me whether the system was armed before locking up the store at night. Saved him checking the system directly.

 

[Bubbatech]

When I worked in a big chain drug store in my high school years, I could hear the ultrasonic alarm system. The manager thought I was making it up, until he tested me one day by turning it on and off. After a while, he would simply ask me whether the system was armed before locking up the store at night. Saved him checking the system directly.

Yes, those things are LOUD! Fortunately also highly directional so they could be avoided sometimes. There were some buildings I could not go into because it was deafening. Now, at 61, I can’t hear them at all.

 

[Vintre]

Add me to the list.

RWD
VIN 28,xxx
75K Kms

Was told that this is to be expected with mileage increase and the Rear Drive Unit wears in.

That is crazy!

Not happy.

Vin