2019 Kona EV Motor Noise Issue

This is really interesting. Looks like quite a process. My car will be going through it on Wednesday the 25th. There are so many steps. I hope my mechanics are detail oriented.

 

If I'm reading this right, despite what my dealer said about replacing both the motor and reduction gear, it appears that they are actually supposed to do multiple checks and repairs in stages, gradually winnowing down to the cause of the noises. It seems possible that they might stop short of full replacement. I hope that's not the case. I know that so far they have only done a test drive to document the sound but have not done ANYTHING repair-wise. Fingers crossed.

 

That's a detailed and interesting procedure, especially the part where the gearbox is assembled to the motor in a vertical orientation, clearly to avoid any actual or perceived influence to the alignment of the splines ... despite the presence of locating dowels intended for that very purpose.

The word "rumble" is interesting as I don't recall too many affected owners using that term. And does that mean or include "wheel-of-fortune", my favorite term, or clicking noise, etc? I suppose "wheel of fortune" doesn't look very professional in engineering documentation. "Wheel of misfortune" might be more accurate however.

If the noise was due to a lack of stiffness or undesired resonance of the motor end bracket why are not all examples affected? To me, the recordings we've heard don't sound like a resonance, more like a bearing failure because the clicks vary in frequency with the vehicle speed. Resonances by definition are fixed in tone, like a tuning fork.

The different size fasteners used after 13 May 2019 may not actually indicate a problem was found and resolved but possibly that a change was applied for lack of any better ideas. Once that change was made they are now stuck with accommodating that difference ongoing. Also note those fasteners are replaced with the motor and gearbox in situ, i.e. not positioned vertically.

There is no path in the flowchart to replacing both motor and gearbox as we know from experience seems to be the most reliable fix for the WoM noise. Nor is there any mention of checking the splines for damage.

My impression is that they still don't really know what the root cause is and are checking everything they can think of. What are the chances that it's nothing more than break-in metal particles in the gearbox damaging the bearings?

 

Ya, their flow chart seems to recommend replacing one OR the other after inspection for noise but the step-by-step instructions allow for replacement of BOTH if noise is found in both. Also, they're supposed to look for signs of undo wear in the gearbox so that might do it too. Now I'm nervous that my dealer was overly quick in saying they were doing both. Maybe they're just saying to hell with it and going for it to ensure it's fixed and out of their hair?

 

Yes, they may be just as tired of the issue as the owners are. Of course they seem to be required to submit recordings of the noises found. Maybe they maintain a library to cover this!

 

I have a few audio files I could contribute to the cause!!

 

From what I remember, those that just replaced the gearbox, eventually had to get the motor replaced as well. In my case, they first replaced the gearbox, and when the tick tick noise came back after about 1000 kms, they also changed out the motor. That fixed it for good. Drove an additional 30K kms after that before I sold it, and it was still good.

 

Yes, there is a real track record of failure when only one element is replaced, and that's just on this forum. You'd have to think that there are even more examples in the wider world that replacing both is the way to go. Again, I'm hoping that's my dealer's thinking too.

 

That's really interesting that different mounting brackets are tried as a fix before biting the big bullet.
Misalignment stresses caused by cockeyed installation??

It's also a nice look at what all the parts are, for those who haven't pulled down service manuals,
since a lot of it is hidden when it's all together.

_H*

 

The nature of the new bracket with its bolt-on "mass" must be aimed more at high-frequency noise than a "rumble" or clicking. The remainder of the TSB procedure seems to be nothing more than identifying and replacing damaged assemblies rather than addressing a root cause. I'm skeptical that Hyundai understand what is kicking-off this problem.

There happens to be an entirely plausible cause and effect pathway between a high level of particles in the oil and the clicking noise and I'm starting to wonder if that's the root cause. Essentially particles make the bearings rough and sticky (ref 1) and that can cause the outer raceway to occasionally spin in the housing because it was designed as a "slip-fit". That effect will be exacerbated by cold, thick oil.

That spin adds clearance between the outer race and the aluminium after some time due to wear and that clearance can result in knocking noises. Clearance at the input shaft bearing in particular could result in damage to the motor spline.

These are problems that can happen in motorcycle gearboxes, stuff I was taking apart in my teens and 20s. I also ran into this once in a professional capacity.

If this is true then the root cause is poor magnetic filtering and as-such the Votex magnetic plug(s) may be less optional than I have recently been suggesting.



From a ball-bearing reseller, my underline:


1 Per the Ioniq owner from Poland who rebuilt his gearbox himself.

 

Advance Consent to Expenditure required?
Hi all of you who have had their Kona drive noise fixed under warranty. Were you required to sign in advance that if Hyundai rejected the claim you would be liable for a UK£75 "investigation charge" regardless of outcome?
I'm taking mine in tomorrow armed with a print of the TSB and a video/audio recording of the noise also on a USB stick for the dealer's service. However this advance permission is going to be asked for. Seems like blackmail to me. Just wondered what others had found.

 

As a note, there are far more UK owners on the SpeakEV Kona forum.

 

Dropped my car off today for the drivetrain work. Had a nice chat with the service manager and he confirmed that Hyundai has pretty much decided that the "try to isolate the source" approach of the last two years has been abandoned and they are just pushing ahead with total drivetrain replacement now. He says that repeatedly having to radically disassemble and reassemble the car (see the TSB above) was making them crazy. He thinks it's going to take "several days" so I'm driving a loaner Elantra in the meanwhile. It's sooooo much quieter than my Kona.

 

There is no question in my mind that the TSB procedure was written by an inexperienced engineer sitting at his or her desk. It truly is a ridiculous process.

You could breach the subject of an early preventative oil change as well since doing that (IMO) could have avoided this problem in the first place. Hyundai would be smart to cover this for free.

 

Yes, although I'll take this opportunity to stress that the contamination issue seems to only occur very early on, unlike with engine oil which requires ongoing care.

That's why I'm suggesting changes at 2,000 and 10,000 km. The second change is just so you can start off with clean oil for the long haul to perhaps 60K.

A new owner over on HyundaiKonaForum has just snagged a "water damaged" 2021 pre-facelift (with only delivery miles) at a considerable discount, US NE area. The car seems to be in perfect condition and he bravely dolly-towed it 150 miles home. I'm hoping he will be able to tackle the oil issue from "new" with a magnetic drain plug install so that we can learn a bit more about if that is effective at dealing with the issue from the start.

 

But since the noise issue doesn't affect 100% of the cars how would you ever be able to ascertain the efficacy of the oil changes and the magnetic plug?