Jim Matthews
Active Member
How long from when you reported the fault until you had a satisfactory repair?
Tapping or Creaking Noise when coasting at low speed
- Thread starter wizziwig
- Start date
- Replies 560
- Views 192K
Almost exactly a month start to finish, including a week to get corporate approval, a week to get parts, and Christmas/new years delays.
Just had all of the ball bearings in the motor and reduction gear replaced.
My Kia Niro EV was produced 10/2018, purchased second-hand from Korea with 64000 km, consequently no warranty for the car.
First signs of clicking/vibrating noises observed at 85-90 thousand km on the odometer, things gradually got worse.
The loudest / most annoying sounds were heard during temperatures of -8 derg.Celcius and lower.
Current mileage 119 000 km.
Sorry, no video/photo report, the job was done by an old-school engine repair specialist and it was his first experience with EVs.
Main observations:
Electic motor rotor ball bearings were evidently worn and rattling when shaken after removal. Almost no grease detected.
No rust or debris inside the motor.
Bearings of the input shaft of the reduction gear were not as loose as the motor bearings, showing slight signs of wear.
Bearings of the secondary shaft were almost intact.
Outer races of bearings were not twisting in the reduction gear housing.
The inside of the reduction gear housing including the OEM magnet and self-installed plugs with magnets were covered with a blackish layer. It took 2-3 times to wipe it off completely with diesel fuel.
Reduction gear oil was transparent and blackish. The oil was changed twice since I got the car from Korea.
Splined connection in evidently good condition.
Looks like Hyundai/Kia engineers didn't account for the operating conditions when designing the electric motor bearings (high rotational speeds and lack of lubrication).
The same probably goes for the reduction gear ball bearings, even though in my case they were in good condition.
My graditude to KiwiME for his continuous efforts and findings on this and other subject related to our vehicles and also to @CarRepairVideos - EV service specialists in Ukraine
My Kia Niro EV was produced 10/2018, purchased second-hand from Korea with 64000 km, consequently no warranty for the car.
First signs of clicking/vibrating noises observed at 85-90 thousand km on the odometer, things gradually got worse.
The loudest / most annoying sounds were heard during temperatures of -8 derg.Celcius and lower.
Current mileage 119 000 km.
Sorry, no video/photo report, the job was done by an old-school engine repair specialist and it was his first experience with EVs.
Main observations:
Electic motor rotor ball bearings were evidently worn and rattling when shaken after removal. Almost no grease detected.
No rust or debris inside the motor.
Bearings of the input shaft of the reduction gear were not as loose as the motor bearings, showing slight signs of wear.
Bearings of the secondary shaft were almost intact.
Outer races of bearings were not twisting in the reduction gear housing.
The inside of the reduction gear housing including the OEM magnet and self-installed plugs with magnets were covered with a blackish layer. It took 2-3 times to wipe it off completely with diesel fuel.
Reduction gear oil was transparent and blackish. The oil was changed twice since I got the car from Korea.
Splined connection in evidently good condition.
Looks like Hyundai/Kia engineers didn't account for the operating conditions when designing the electric motor bearings (high rotational speeds and lack of lubrication).
The same probably goes for the reduction gear ball bearings, even though in my case they were in good condition.
My graditude to KiwiME for his continuous efforts and findings on this and other subject related to our vehicles and also to @CarRepairVideos - EV service specialists in Ukraine
Last edited:
KiwiME
Well-Known Member
Well, thank you for that acknowledgment ... and the valuable information in your post! Glad I popped into this forum today!
A couple of things interest me:
Was the OEM magnet loaded with ferrous particles and was it loose in its pocket? As you're probably aware I'm theorising that the OEM magnet rattles around in the oil flow and abrades captured metal against the pocket, breaking down the iron and releasing new aluminium particles. The aluminium is what I believe is blackening the oil.
Did you notice the condition of the carbon ring brush at the motor output shaft? A lack of performance there can of course will allow current discharge across the motor bearing raceways, which will eventually cause noise. The type of brush used is not considered to be very effective in industrial motor applications.
Hyundai/Kia have changed to a "wet" motor design for the new Niro and upcoming Kona EVs which should address the failed lubrication. I think also the motor shaft grounding arrangement is more robust.
A couple of things interest me:
Was the OEM magnet loaded with ferrous particles and was it loose in its pocket? As you're probably aware I'm theorising that the OEM magnet rattles around in the oil flow and abrades captured metal against the pocket, breaking down the iron and releasing new aluminium particles. The aluminium is what I believe is blackening the oil.
Did you notice the condition of the carbon ring brush at the motor output shaft? A lack of performance there can of course will allow current discharge across the motor bearing raceways, which will eventually cause noise. The type of brush used is not considered to be very effective in industrial motor applications.
Hyundai/Kia have changed to a "wet" motor design for the new Niro and upcoming Kona EVs which should address the failed lubrication. I think also the motor shaft grounding arrangement is more robust.
Last edited:
Was the OEM magnet loaded with ferrous particles and was it loose in its pocket? As you're probably aware I'm theorising that the OEM magnet rattles around in the oil flow and abrades captured metal against the pocket, breaking down the iron and releasing new aluminium particles. The aluminium is what I believe is blackening the oil.
OEM Magnet was moderately covered with ferrous particles as much as plug magnets (installed ~25 000 km ago). It was loose in the pocket, this allows to insert it during assembly of the reduction gear. It sure can release ferrous particles and probably did, not sure if the friction was strong enough to scrub the aluminum off the housing. The specialist making the job didn't notice any abnormal wear in the region of the pocket.
Did you notice the condition of the carbon ring brush at the motor output shaft? A lack of performance there can of course will allow current discharge across the motor bearing raceways, which will eventually cause noise. The type of brush used is not considered to be very effective in industrial motor applications.
Sorry, the specialist does not recall seeing this carbon ring.
Hyundai/Kia have changed to a "wet" motor design for the new Niro and upcoming Kona EVs which should address the failed lubrication. I think also the motor shaft grounding arrangement is more robust.
Good that Hyundai/Kia are learning their lessons. I can't judge if this mistake is a result of negligence or poor engineering, any way we, the gunea pigs, are suffering.
OEM Magnet was moderately covered with ferrous particles as much as plug magnets (installed ~25 000 km ago). It was loose in the pocket, this allows to insert it during assembly of the reduction gear. It sure can release ferrous particles and probably did, not sure if the friction was strong enough to scrub the aluminum off the housing. The specialist making the job didn't notice any abnormal wear in the region of the pocket.
Did you notice the condition of the carbon ring brush at the motor output shaft? A lack of performance there can of course will allow current discharge across the motor bearing raceways, which will eventually cause noise. The type of brush used is not considered to be very effective in industrial motor applications.
Sorry, the specialist does not recall seeing this carbon ring.
Hyundai/Kia have changed to a "wet" motor design for the new Niro and upcoming Kona EVs which should address the failed lubrication. I think also the motor shaft grounding arrangement is more robust.
Good that Hyundai/Kia are learning their lessons. I can't judge if this mistake is a result of negligence or poor engineering, any way we, the gunea pigs, are suffering.
Finally got my local dealer to admit that they hear the noise... Guess there is some new protocol from Kia before they replace the motor.
They are ordering parts and I will update when that is completed. They say they had another one that they did this protocol on and it solved the noise.
We shall see...
They are ordering parts and I will update when that is completed. They say they had another one that they did this protocol on and it solved the noise.
We shall see...
Do you know if the new protocol is covered under the 100k powertrain warranty?
It seems to be covered under warranty... Not sure which one. Certainly within 5 years should be covered.
60k or 5 yr. Already out of my warranty period. I only have the 100k powertrain left. Not that Kia was able to fix anything when I had the full warranty anyway
Jim Matthews
Active Member
Amen, Reverend.
I don't see why it wouldn't be covered under the 100k warranty. Doesn't hurt to try...
I’ve tried twice. Both times they tell me the sound is “normal”.
Our 2019 Kia Niro EV is now exhibiting the rumbling noise, reproduced in Kia TSB 234. The problem is that the noise intermittent - there some days, gone other days. I have an appointment with the Kia dealer on May 30th for a diagnosis. Any tips on how to get the car to emit the noise? I’m concerned I’ll get the run-around based on the posts here.
I've noticed that going up hills makes the sound worse so you might try that. The sound definitely gets worse once you start hearing it. I first started hearing it at a low level probably 9 months ago and now it is very evident even on level terrain. When the tech drove with me, I made sure the windows were all closed and the radio off to provide the best environment to hear the noise. It was pretty obvious, and he agreed it was the noise in question. Happens most evidently between 10-25 mph under acceleration for me.
They’re probably trying to run out your warranty. Having dealt with Kia corporate and the dealers for a year now one problem SEEMS to be that Kia makes it hard to approve warranty repairs, so they keep telling you it’s normal or it can’t be fixed. When your warranty runs out suddenly it will be a new problem they’ll be happy to throw parts at on your dime. Just my feeling after dealing with them for so long now. They don’t want to own up to their defective motors.
