ronbot
Active member
This problem is on the rise as these cars reach higher mileage.
My 2015 BEV (Tera, w/every option) started this motor bearing whine at about 94k miles. The dealership (BMW South Kansas City) tried to get me to trade it in for $2500... what an insult.
They estimated over $16k for the repair, trying to convince me it was EME (Inverter), Gearbox, and Electric Motor.
There's a lot of owners out in public forums and Facebook Groups that have had this happen, outside of warranty, and with enough coaxing - get Goodwill replacement of the motor (parts only, customer pays labor)
I'll be pushing at BMW NA pretty hard... I just do not accept that this $50K car wasn't designed to last longer than 90k miles before suffering a terminal failure that costs more than the current used market price of the car to fix.
BMW changed the motor front bearing design from a normal roller bearing to a tapered roller bearing in 2018, which fixed the "no load - self destruct" problem with normal cylindrical roller bearings. When a roller bearing already has race wear, and is then run with little-or-no lateral load, the rollers can stop spinning. Then when lateral load is applied (motor torque jumps up), the 'non-rotating' rollers will skim along the inner surface of the outer race, WIPING any oil film away... then the next roller is rubbing metal-to-metal, causing serious wear.
This condition won't happen in a tapered roller bearing, since they require some pre-load to keep the rollers seated. BMW knew this years ago, but only fixed it in the 2018 model year.... the same year they increased the power output for the "S" model.
This new BMW part number immediately became the Service Replacement Part for all years of the i3 that had a bearing failure... so they won't get repeat failures and have to do it over again.
It is a known design flaw... but they won't admit it until it becomes a Class Action legal matter.... if even then.
edit: One of the outstanding design flaws they made was choosing cheap "sealed" bearings for a over-billion-cycle electric motor - that spins over 11,000 RPM, in all kinds of climate environments.
My 2015 BEV (Tera, w/every option) started this motor bearing whine at about 94k miles. The dealership (BMW South Kansas City) tried to get me to trade it in for $2500... what an insult.
They estimated over $16k for the repair, trying to convince me it was EME (Inverter), Gearbox, and Electric Motor.
There's a lot of owners out in public forums and Facebook Groups that have had this happen, outside of warranty, and with enough coaxing - get Goodwill replacement of the motor (parts only, customer pays labor)
I'll be pushing at BMW NA pretty hard... I just do not accept that this $50K car wasn't designed to last longer than 90k miles before suffering a terminal failure that costs more than the current used market price of the car to fix.
BMW changed the motor front bearing design from a normal roller bearing to a tapered roller bearing in 2018, which fixed the "no load - self destruct" problem with normal cylindrical roller bearings. When a roller bearing already has race wear, and is then run with little-or-no lateral load, the rollers can stop spinning. Then when lateral load is applied (motor torque jumps up), the 'non-rotating' rollers will skim along the inner surface of the outer race, WIPING any oil film away... then the next roller is rubbing metal-to-metal, causing serious wear.
This condition won't happen in a tapered roller bearing, since they require some pre-load to keep the rollers seated. BMW knew this years ago, but only fixed it in the 2018 model year.... the same year they increased the power output for the "S" model.
This new BMW part number immediately became the Service Replacement Part for all years of the i3 that had a bearing failure... so they won't get repeat failures and have to do it over again.
It is a known design flaw... but they won't admit it until it becomes a Class Action legal matter.... if even then.
edit: One of the outstanding design flaws they made was choosing cheap "sealed" bearings for a over-billion-cycle electric motor - that spins over 11,000 RPM, in all kinds of climate environments.
