High-Pitched Motor Noise

I have made progress identifying my "motor noise" using my sound level meter (SLM) and acoustic spectrum analysis App. In the front of the motor compartment, with hood open, power ON and Drive N, the noise is about 67 dBA. This is 17 dBA higher than with the Power OFF (no noise).
Moving the SLM around, the noise seems to max out near the very front of the motor compartment, and is not near the drive units.
The noise acoustic spectra peaks out around frequency of 400 Hz.
With the hood closed and about 1-ft. in front of the car, the noise level is 64 dBA .
I'm satisfied that this is probably the VESS noise, as several of you have described. Thx much for your help.

Ironic, I have had a KIA Soul-EV for 5 years now, with the VESS silent from day-1. My KIA dealer Service has tried to fix the VESS system, with no success.

 

Just got my Kona back yesterday after four long weeks in the shop. Gear Drive Unit replacement.

I had almost forgotten what it was like to drive my car without extra noise...

I just hope it doesn’t come back. Only time will tell!

 

I was driving in the basement carpark the other day with the windows down. With my VESS off, I could clearly hear the hissing noise that others have described here. My car has only clocked 3000 kms. I cannot be absolutely sure if that noise was there when it was new. I began reading the forum about this issue, but the more I read, the more unsure I am if this hissing noise is actually abnormal.

The reason I theorised why it could be normal, many have complained and recorded the other unrelated clicking (Wheel of fortune) noise from their Kona or KIA Niro. When I listened to these recordings, the hissing sound could also be clearly heard but was not flagged out as an issue to them.

Here are some of the recordings made by others that pointed to the clicking noise but seem to disregarded the hissing noise that was also present.

https://www.insideevsforum.com/community/index.php?threads/clunking-vibration-type-sound.7262/
Thread no 1

 

This is how my Kona model 2020 sounds like. Looks like Hyundai has not improved it at all. First part is reversing and then few time acceleration/deceleration on Eco mode, VESS off, regen level 2, no audio, no AC, no fan.

 

Did it sound like this immediately after you took delivery of your Kona?

 

Honestly,I’m not 100% sure but I’d say no. Mine has 700km,as of today.


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Sounds like a normal EV engine to me. They are not totally silent.

 

It is the high pitched hissing sound that I’m not sure about. I was expecting the low and middle frequencies.

 

Where did you place the microphone in that recording?

 

Vince08; you wrote that you turned the VESS off; How is that done?
As I wrote before, VESS is ON , even in Drive= N. But if you put parking brake ON ("P), VESS noise stops.

 

Keep in mind that in that video the microphone is under the hood, next to the motor. When my Niro was making that clicking noise, I never heard any hissing. No hissing still after motor was replaced. That could be explained by better sound proofing on the Niro. The difference in drivetrain noise was very evident when I test drove the Kona and Niro back to back before purchase. So maybe Niro is making the same hissing noise as the Kona but it's simply not audible in cabin or outside the car, even with Windows open.

I did develop a cricket chirping sound as I noted in the other recent noise thread.

 

On top of the engine plastic cover


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My Asian spec Kona comes with a VESS button on the dash. Here is an image of the VESS button taken from the Internet.

 

Mine sounded exactly like yours, i.e. the high pitch hissing noise during acceleration and during regen. Would you be able to accept it if was there from day one?

I am trying to find evidence that the noise is inherent of the car and to just ignore it. I don't hear them inside a basement car park with the windows up and VESS off but my daughter could still faintly detect it.

At my next servicing, I may ask the mechanic about it and perhaps compare it with their test drive car.

 

The thing is that the hissing noice is barely (if any) heard during driving with all windows up. I got my Kona in March and the weather was still chilly at that time so I hadn’t driven with open windows,that’s why I’m not 100% if the sound was there from day 1. I’ve already asked my dealer and I’m waiting for his response

 

We noticed the hissing for the first time last week. But, we got our car in December last year and it’s been the first few times we’ve driven with the windows down in Canada. Definitely could’ve been there since day one, but am not sure.

We have a 2020 with around 5000km.

 

I got mine in March, 2019 and it was completely silent until about 3,000 km. Now I am at nearly 32,000 km and it still makes the noise and if anything, the hissing is louder now than this time last year. Dealership won't deal with it. Hyundai Canada won't deal with it. It makes me upset every time I hear the hissing noise. I'm trying really hard to consider it as a "normal" sound that the car makes but it's really not. Sounds like a bad break job.