2019 Kona EV Motor Noise Issue

Most car transmission systems in modern cars are without any filtration and with lifetime lubricant fills.
So there is no extreme deviation from Hyundai/Kia in this respect.
Another extreme would be re-lubrication every 500 miles like on early cars produced 100 years ago.

 

Yeaah .. I'm not going to get into a to and fro with you about this but for the record that's simply not true. Lifetime fill is possible because they have particle filtration means, almost always a magnet. From the service manual of VW's 7-speed DSG, a very common automatic with no scheduled maintenance:

 

7 speed DSG is immensly more complex contraption with much more wear and tear then simple reducer for an EV. And yet they seem to get away with only a magnet.

 

"simple" reducer gears in airplanes and helicopters always have magnetic plugs even with indicator lights (for obvious reasons). Wonder why they install them ...

 

It would be nice to get some documentation on motor/reduction gear assembly. The rumors are that there are actually allready 3 versions available for Kona EV. And I suspect the changes between versions are due to different problems being found over time. It would be nice to see what are those differences.

 

Update on my 2022 Kona EV engine sound "wheel of fortune"
Innitially my dealer said "it doesnt sound like a problem " and after I complained at Hyundai Europe they recognized the problem and they ordered a new motor.
I now have to wait for a replacement.
I thought that 2022 kona ev have this motor problem solved...

 

Just had the traction motor replaced after waiting for 3 months for the part to be delivered. The gear noise is completely gone and our 2019 Kona is now nice and quiet. The previous “fix”, replacement of the reduction gear, left the car feeling like a tractor and we had to live with this for 3 months. I think a spline shaft got damaged either by the old reduction gear or when the new reduction gear was installed.

 

I'll admit to not knowing a lot about the workings of drive trains but how would replacing the motor while keeping the old "gears" change the noise issue? Isn't it the gears that are making the noise? Wouldn't they need to be replaced along with the drive motor?

 

Sorry should have been clearer, they put in a traction motor assembly that includes the reduction gear.

 

Thank you.

 

I have been noticing noises lately. I was second guessing myself because it's normal to wonder if a noise is new or louder or different when you're constantly exposed to it.

Well, I just took my sister for a drive and I'm not second guessing anymore! She's driven in the car in the past so has a base-level of familiarity. She also drives a Leaf so is experienced with an EV's quirks.

Her response upon accelerating, regenerating and stopping about one minute into our trip was as follows, and I quote: "Holy hell! Why haven't you taken this thing in to the dealer. It's ridiculous!"

So I guess I will soon. Now I just need to convince the dealer that's it a "Holy hell" moment.

 

Try to convince them the noise is coming from the traction motor not the reduction gear and be prepared for a long wait.

 

I've become accustomed to long waits so that doesn't worry me it's the idea of convincing the dealer that the sounds are new, bad, and a problem that needs to be fixed that really worries me.

And, of course, that the noise is going to escalate into actual problems using the car too.

 

To those of you with expertise in the area:
How can an electric motor make noise? Does it mean that there's something physically out of kilter? Is it the drive train or is it a combination of the two systems?

My car makes a very loud "buzzing" noise which rises in pitch and volume with acceleration and is completely silent when power isn't being applied.

And when I lift my foot and regen kicks in it is really loud and sounds like a steel knife being honed on a gritty grinding stone then winds down to the"wheel of Fortune" noise as it slows to a stop.

Any idea what single or multiple issues might cause these symptoms? I'd love to be a bit informed when I try to persuade my dealership that it's not "normal".

 

Never had those sounds, just the low speed ticking, after which they replaced the reduction drive and motor. Your noises might be an advanced stage of wear towards breakage, well beyond the low speed ticking. In can case, you should take it into your dealer and have them check it. From your description, can't see how they could ignore that.

Did you change your reduction gear oil? Would be interesting to see what that looks like. That is another thing the dealer should be checking.

 

https://recorder.google.com/share/f4b588c6-715c-4f37-93e7-56793dc73d31
Driving
Certainly doesn't capture the intensity and volume of the "buzzing" but it's the best I can do.

https://recorder.google.com/share/30474f52-9afd-4695-af2f-069c8f57e2f1
Driving, decelerating with regen

https://recorder.google.com/share/226fef34-4f0c-4983-ad38-5b83653e0bbb
Foot one and off accelerator in bursts.

All of these sounds in real life are so loud that they're not drowned out by the radio.

 

Normally you would try and match the sound frequency with shaft revs per second, which worked for the more-common ticking noise. But even the motor speed is only about 8 times wheel speed and the sound in your video sounds much higher frequency, perhaps a resonant harmonic from current switching in the motor windings.

It could be the motor or inverter causing the noise rather than the gearbox. Since you're under warranty I'd say it's up to the dealer to figure that out but chances are they're no wiser than any of us and would have to send a sound file to S. Korea.
But if it was me I'd pull the gearbox first. If the splines were shagged out I'd replace both motor and gearbox, otherwise just the motor. If that doesn't fix it then the inverter.
But I'd be disappointed if the dealer did not accept that this is a problem.

EDIT: Yeah, after listening again I'm not thinking it's electrical. Sounds like a very rough ball bearing or spline.

 

Thank you. I'm glad to hear that you (and my sister ) hear that something is clearly wrong. That's a start.
Where would the bad bearing be? In the motor? In the gear box? I don't know this stuff.

 

Wow, that is really bad, never heard anything like that before. There is no way the dealer could call that normal. Not sure how good/competent your dealer is, but you want to know that the replacement was done properly (torques, etc). If unsure, call around to see which one has done motor/gearbox replacements before.