[pe1979b]

Does anyone hear a high pitched whine when driving? It happens at low, medium, and high speeds but only when accelerating. It's not consistent in that it doesn't happen all the time. It's definitely tied to the power train as it always ceases when I let off the accelerator. To be certain I also turned off the climate control and entertainment system and it was still present. It's not obnoxious but is noticeable when chatting with passengers. Anyone have any experience like this? Is it normal? Or should I take it in and have it looked at?

 

[lagagnon]

Isn't what you are hearing the normal sound of any electric motor winding up? Our Volt and my friend's Leaf makes exactly the same sound on acceleration - somewhat of a higher pitched electric motor whine - which is quite normal....

 

[pe1979b]

I'm unsure what it is. I would expect if it were a normal sound of the electric motor winding up that I would hear it consistently every time it does so. However I do not hear it all the time. I'll pay a little more attention to it when I'm out today. Thanks for the response.

 

[mike100]

It is the carrier frequency of the pulse width modulation power transistor switching that you hear. At higher rates of acceleration, the motor voltage goes up and you hear the fluxed parts physically vibrating.

 

[pe1979b]

It is the carrier frequency of the pulse width modulation power transistor switching that you hear. At higher rates of acceleration, the motor voltage goes up and you hear the fluxed parts physically vibrating.

Does this mean we have a Flux Capacitor in our cars

 

[Tacoma]

What year is it?
How long have you had it?
When did you first notice it?

 

[pe1979b]

What year is it?
How long have you had it?
When did you first notice it?

It's a new, 2018 LT which I purchased on June 1st. I noticed it a week after I purchased it (when I had a passenger in the car and was chatting with her).

 

[Tacoma]

My thought is, you are under warranty, take it in to the dealer and ask them about it.

Do you know anyone else with a Volt you could ride in to make a comparison?

 

[Tacoma]

This may be unrelated, but there was a discussion about a few people experiencing a whine from the compressor on hot days.

https://gm-volt.com/forum/showthread.php?326065-loud-(compressor-)-whine-during-hot-days

Take it in, and get it checked out.

 

[Steverino]

A related thread using a tone generator to measure the sensitivity of your hearing to certain sound frequencies. Not everyone may hear what you hear:

https://gm-volt.com/forum/showthrea...razy-high-ringing-noise&p=1462833#post1462833

 

[Monzsta]

If you listen to AM stations occasionally you can hear some noise if you're hard on it. There's one spot I always hear it, but it's right under a power line. I think the power line somehow amplifies the motor noise. I've toyed with using a cheapie unfiltered radio to make a decent audio of the electrical activity.

 

[pe1979b]

Thanks to everyone for their feedback.

@Tacoma: I plan to do so but wanted to check with the board to see if it was normal. No use taking some time to stop by the dealer if it's normal. Unfortunately I do not know of any other Volt owners.

@Monzsta: When we first noticed it we turned off the radio thinking it may be the source. It was not. We also did the same for the climate system.

This morning I was paying a little closer attention and the best way I can describe the noise is similar (or maybe the same) as that which you hear by using the regenerative braking paddle. Since the trip was only a mile I didn't have much time to gather more information. When I go out later I'm going to use L instead of D to see if the noise is present.

 

[Tacoma]

You could make a video and post it here.

 

[pe1979b]

You could make a video and post it here.

I've considered making a recording of the noise but at this point it doesn't appear as if it's common (or else others on this forum would have confirmed it). I think at this time I'm going to take it to the dealer and ask them about it.

 

[Tacoma]

My Volt, and all EV's have a little bit of sound as you accelerate and decelerate, but almost nothing compared to a combustion engine. If you search this site for buzzsaw noise you'll find threads on an occasional bearing failure which makes a fair amount of noise.

Here is one that popped up on a google search:
https://gm-volt.com/forum/archive/index.php/t-103913.html

 

[pe1979b]

My Volt, and all EV's have a little bit of sound as you accelerate and decelerate, but almost nothing compared to a combustion engine. If you search this site for buzzsaw noise you'll find threads on an occasional bearing failure which makes a fair amount of noise.

Here is one that popped up on a google search:
https://gm-volt.com/forum/archive/index.php/t-103913.html

Thanks for the reference. Thankfully it's nothing like that. I'm thinking it's normal but I figure why not have it checked out since it's under warranty. I've scheduled an appointment for Friday morning, I'll report back what they say.

 

[hellsop]

Does anyone hear a high pitched whine when driving? It happens at low, medium, and high speeds but only when accelerating. It's not consistent in that it doesn't happen all the time. It's definitely tied to the power train as it always ceases when I let off the accelerator. To be certain I also turned off the climate control and entertainment system and it was still present. It's not obnoxious but is noticeable when chatting with passengers. Anyone have any experience like this? Is it normal? Or should I take it in and have it looked at?

Sounds like you're describing motor controller whine. Comes from the box that is responsible for making the DC power from the battery into AC power for the motors and then turning it on and off a couple thousand times per second to that the motor can have variable "thrust" applied and output less than full torque. It's a little higher than typical mosquito pitch, the loudness definitely varies with the throttle not the speed of the wheels though the pitch may follow the wheels, and it's completely normal.

 

[pe1979b]

Sounds like you're describing motor controller whine. Comes from the box that is responsible for making the DC power from the battery into AC power for the motors and then turning it on and off a couple thousand times per second to that the motor can have variable "thrust" applied and output less than full torque. It's a little higher than typical mosquito pitch, the loudness definitely varies with the throttle not the speed of the wheels though the pitch may follow the wheels, and it's completely normal.

Thank you for this feedback. I'm guessing it's probably normal but I want to be certain to get it addressed if it's not. When I drove it earlier I wasn't able to confirm I heard the specific noise I'm inquiring about but I did hear some light noise which sounds like when you use the regenerative braking paddle (anyone else have that noise or is it just me?) I then shifted into L and it immediately went away and I didn't hear anything until I switch back to D. It's not obnoxious but it is noticeable when the cabin is quiet. Enough so that my friend mentioned it to me (by asking me what it was)

 

[hellsop]

It's amazing what you can hear in a car when there's not 5000 explosions per minute happening four feet away.

 

[pe1979b]

Took the car into the Chevy dealer this morning. I don't have anything to report as the car was not making the noise and therefore there was little they could do. They checked for service bulletins, inspected to fluid levels, and gave the car a quick look.

I will monitor the car and see if it recurs. Unfortunately I am unable to hear the noise when listening to anything. Thus I don't know under what circumstances it happens and how often it happens.

Thanks for everyone's suggestions.