High-Pitched Motor Noise

Discussion in 'Hyundai Kona Electric' started by SeanH, Apr 29, 2019.

  1. MGrognon

    MGrognon New Member

    Nah not wind as when you are coasting (no regen, no acceleration) there is zero sound even at high speed. It's only when motor is working/there is some regen going on.
  2. XtsKonaTrooper

    XtsKonaTrooper Active Member

    Im around the same age and i can hear hissing, which isnt annoying for me either. Im not knowledgeable enough in EVs either, to say its a defect. Comparing it to other brand EVs is a moot point cuz their engines are designed differrently. Now if one Kona has it and another doesn't, then thats something that needs to be answered.
    Brennan Raposo likes this.
  3. MGrognon

    MGrognon New Member

    The very first time you hear it very slightly it's @ 1min57. Then clearly at 2min11 or so and as pointed out above, the time you hear the "most annoying" part of it is around 2min30-2min35 when lots of regen, but you hear it throughout the video pretty much (except when the guy floors the Kona or at high speed where you only hear wind and road noise that, likely, drown out the sound).
  4. victor_2019

    victor_2019 Active Member

    this is the hissing noise that I hear in my own car. it's a very high frequency hiss so it's normal for older people not to hear it.

    but to be honest I don't care much about this noise. it's not making me scream in agony or anything like that. it's just a hiss.
  5. MGrognon

    MGrognon New Member

    A theory on the French (Quebec) FB group where this is being discussed is that there may be a component where some people hear higher frequencies / are more easily annoyed by this yes, but also maybe that this could also be due to some units having less sound dampening than others (as to why ; not sure... Could be that plastic cover on the "motor" not being properly installed or insulated or something... Or it could be that a different maker/model is being used between Konas for some of the motor/inverter components, with some being louder/more problematic ... Who knows). It doesn't make me scream in agony either, but it's annoying enough to make low speed (< 60 kmh) rides honnestly unpleasant unless AC at full blast / radio on (which drowns out the sound) and to OP's point ; I also do get people turning their head (and not due to VESS) and someone in my family did ask me if I had an issue with my brakes or something (when the car is passing by, it sounds like old/rusty brakes rubbing unless you're on Level 0 regen).

    I think it's possible all Konas have this sound, but that some might be unacceptably louder than others. As to why, well ... Not sure still.

    The guy who did the video says he does not hear the sound, even with windows down. HE was actually surprised to hear so much noise when he listened to the audio taken from under the hood (and he does hear the hiss obviously in his video).
    Last edited: Aug 1, 2019
  6. victor_2019

    victor_2019 Active Member

    this noise is basically created by current harmonics in the motor.

    the inverter creates current harmonics due to the way the current waveform is constructed.
    the current harmonics create magnetic and torque ripple in the motor.
    the magnetic/torque ripple in the motor causes the motor frame and internal components to physically move/vibrate. the motor is attached to the car frame which then in turn vibrates.
    this causes sounds at various frequencies.

    the motors are not all physically identical. there are manufacturing tolerances which result in slightly different mechanical and magnetic parameters in each motor and then this results in slightly different vibrations in two different vehicles. this might explain why some cars sound louder than others (!!assuming this is actually true. you can only say that different cars have different sounds if the same person in the same circumstances listens to multiple vehicles. you can't judge this based on what the owners report because different people have different hearing ranges and just because someone doesn't hear this noise it doesn't mean the noise is not there).

    in addition I assume the manufacturing tolerances also result in slight differences in the actual car bodies which will then resonate slightly differently and also cause differences in sound.

    all of the above is normal from a technical point of view and not a sign of a failure in any component.
    Kamloops_KoNa and Wildeyed like this.
  7. MGrognon

    MGrognon New Member

    Your insights are actually very helpful in understanding more as to where the sound could come from, thanks for that. And I agree this does not likely mean "failure of any component" is imminent. It is very possible this is the "nature" of electric motors and all of them sound like this TO SOME EXTENT.

    This is however an issue that to me (and other people like OP obviously) makes owning / using the car a very unpleasant experience (to me the sound gives me a feeling similar to nails on a chalkboard) so I think this thread is simply us trying to figure out how to resolve this (or lessen it as much as possible). Is it by changing a specific part, is it by adding soundproofing somewhere/somehow, etc... I know this might sound trivial to some and it is very possible this is just how the motor sounds on the Kona but again, given the thread here, the FB discussions, people making videos abour it... It is obviously annoying enough for some people to investigate and try to see if there is a way to fix it or at least attenuate it (or in some instances give up and sell the car, which to be very honnest, I am considering too because of this specifically). I otherwise like the car a lot, so if there is ANY way to fix this, I want to know before selling it and losing money. If you have suggestions on how this can be attenuated, I'd like to hear them given you seem knowledgeable in this field.

    I do plan on attending a local "Kona meeting" this summer, if I do attend I will for sure try to see if I hear any differences in the hiss between Konas to see if truly there are differences between models in volume, or if they all sound the same and some people simply hear it more / less than others.
    Brennan Raposo and Kitsilano like this.
  8. victor_2019

    victor_2019 Active Member

    the best way to solve it would be for hyundai to change the inverter switching pattern to one that doesn't create such a hiss, or to increase the switching frequency of the inverter.

    but that doesn't mean it's possible or easy to do. Increasing the switching frequency increases losses in the inverter. but perhaps they could tweak the frequency just a bit?

    And as far as switching pattern/algorithm is concerned, they probably have good reasons for choosing the control method they did and there may be some technical challenges with changing that.

    since this is high frequency noise it should be easy to deaden this sound in theory but I don't know how much of the engine bay you'd have to cover to eliminate the sound. and are you tying to completely eliminate it or just not to hear it when you have the windows closed?
  9. Reading your last post it makes me think of active noise cancellation. Have a microphone record the sound and have the VESS play the amplitude-reversed sound ...

    Sent from my moto x4 using Tapatalk
    robxb likes this.
  10. XtsKonaTrooper

    XtsKonaTrooper Active Member

    Well if ppl think it might be model specific, i have an Ultimate.
    Just another note, some think it might be around the plastic cover. Remove it, and see if it increases or decreases the hissing noise.
    Enquiring minds wanna know, hehehe
  11. SeanH

    SeanH Member

    The audio I posted earlier on this thread is taken with the car on a lift. No wind noise, no VESS, and the ability to walk around under the car while it is running to localize the noise. It is not the wheels, not wind, etc. It is coming from something in the motor/gearbox/inverter block.
  12. XtsKonaTrooper

    XtsKonaTrooper Active Member

    Did you take the cover and drive it, to see if it gave different results.
  13. SeanH

    SeanH Member

    I didn't remove the cover, but it certainly wasn't vibrating.
  14. XtsKonaTrooper

    XtsKonaTrooper Active Member

    No but it can either, increase or decrease a noise.
  15. Definitely noticeable in sport mode, maybe that's why I have not heard it on mine. I have only squealed the tires twice and drive in ecco mode constantly. ( Plus I don't own a cell phone to tape in the motor compartment).
    Let us know JerContact if the Dynomat works for you.
  16. wizziwig

    wizziwig Active Member

    What is the ticking sound heard between 1:36 to 1:45 in the video?
  17. MGrognon

    MGrognon New Member

    Fan from the cooling system (either cooling the cabin or battery, the guy says at the start of the video it's 30+ degrees outside even if dashboard shows 29 C).

    It does sound pretty bad / loud around that time but I've never noticed it being this loud in the cabin or outside the vehicule, you would only hear this when the car has AC at full blast and/or is cooling the battery I think? I could be wrong though.
  18. Still don't hear anything on our car, just the VESS, and we have tried hard to listen (driving close to buildings with windows down, etc). There is considerable road noise once you get going faster.

    So don't know if it is our ears or our car is different. Would be interesting if someone sensitive to this sound would drive with us in our car, and listen for that noise. Having said that, don't really want to know if it does indeed make that noise,... haha. Ignorance is bliss sometimes...
    XtsKonaTrooper likes this.
  19. brulaz

    brulaz Active Member

    High frequency noises can be lessened with sound dampening material.
    Hyundai could prolly fix this easily if they tried.
    Brennan Raposo likes this.
  20. dborn

    dborn New Member

    As I stepped out the local hardware store (Reno-Depot in Vaudreuil for you Quebecers ;) ) there was a nice lady unplugging her Kona from the L2 charger in the parking lot. We chatted for a few minutes and she told me how much she loved her Kona. She used it to regularly drive to Toronto, Ottawa and Quebec city (from the Montreal region). I stood by her car when she drove off and heard absolutely no hissing sound of any kind. I do suffer from tinnitus so there might be some upsides to that condition after all. o_O In any case, no painful nails-on-blackboard hissing sound.
    Hope I don't hear mine when I eventually get it...
    robxb and electriceddy like this.

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