[hervorragend i4 ?]

@hervorragend i4 ? Would love to see pictures of the brushes themselves -- please ask the tech to document it to enrich the rest of this community, thank you!

I'll ask... but not sure I'll get it. They already disassemble/clean/reassemble 2 times ... and the damp-proof (?) test was not ok. Second time with BMW France tech. Now waiting for BMW instructions. I'm personnaly asking without believing it for a motor replacement.

 

[hervorragend i4 ?]

Just crazy that the motor needs to be removed to service brushes. BMW should make the car more serviceable. I replace brushes in small motors often and usually there is a separate access to make it easy.

... and remove the complete rear axle to remove the motor.

 

[bbgator]

@northerncalguy -> There are already very good professional pictures of the brushes. Under the title 5th generation motor, the 2nd picture shows the 3 brushes. They look like any other set of brushes for motors. On a slip ring similar to most alternators. Slip ring style last longer but still not as long as brushless. Still considered a replaceable item that should be easy to access. Ideally 1-hour or less job if designed for maintenance (which it wasn't).

https://www.motortrend.com/news/bmw-ix-m60-brushed-electric-motor-tech-deep-dive

A lot of info on

https://www.i4talk.com/threads/bmw-electric-motor-tech.8281/?post_id=169970#post-169970

 

[hervorragend i4 ?]

Decision finally taken by the factory : engine has to be replaced. The new one is on the way !

 

[KBS]

The motor needs replacing. To me an engine involves combustion. I’d guess the problem all along was a motor issue, not specifically the brushes.

 

[hervorragend i4 ?]

The motor needs replacing. To me an engine involves combustion. I’d guess the problem all along was a motor issue, not specifically the brushes.

I guess the problem never came from brushes too.

 

[hervorragend i4 ?]

... But it took exactly 2 months to come to the f***ing decision. I'm exhausted.

 

[bbgator]

Electric motor replacements are rare. Usually after overheating or bearing going bad. Still rare on a new motor.

 

[i4m50Norway]

Electric motor replacements are rare. Usually after overheating or bearing going bad. Still rare on a new motor.

Well, they had to replace a few Thousands front drive units for the i4M50 production in October - November 2022.
(Including mine and a few hundred norwegian cars - that got a stop sale, and three months delayed delivery - That was when BMW paid an iX rental for meeting for three months / 9000 km)

 

[hervorragend i4 ?]

Electric motor replacements are rare. Usually after overheating or bearing going bad. Still rare on a new motor.

I hope the 250km highway trip at about 140km/h (85/90mph) was not a reason for overheating ! Temperature about 25°C (77°F). If it is the case, the car won't be mine for a long time.

 

[hervorragend i4 ?]

After exactly 2 months and 1 week waiting ... I have my car since one week ! ... The new motor already has 1.500 km and everything works incredibly well 🙂.

 

[bbgator]

I hope the 250km highway trip at about 140km/h (85/90mph) was not a reason for overheating ! Temperature about 25°C (77°F).

That sounds idea, I wish it was 25C here. More like 35C (95F). USA is a large country. Driving 130km/h on 35C for 2000km or longer is a common thing to do in the USA. I do that about 4 times a year. If that overheats anything, then BMW needs to go back to the drawing board. There are many deserts around the world where it is 44C+ and people drive at high speeds, so the cars have to be designed to handle those cases.

 

[i4m50Norway]

No problem at 225 kmh @ 33C in Germany last week :

Charging at 30 Celsius :

The Skoda Enid (Same as VW id.4) was really struggling with charging speed - with whining cooling system :

My i4 - was faster even at 92 percent SOC :

 

[F1Geek]

Anybody know the slip ring longevity on Renault Zoe or other Renault models? Nissan also using EESM in Ariya (probably Renault tech). So BMW is not alone in using EESM.

 

[bbgator]

impossible to guess lifetime of a slip ring without a lot of info on material and manufacturing process. Slip rings are in alternators. They last from 60K miles on a GM to 200K miles in a Honda or Toyota. That equals anywhere from 3 Million to 15 million revolutions. Even then, usually the bearings on motors start to go. Depending on the drivetrain gear ratio at even 15 million revolutions, that isn't a lot of miles. With Tesla Model S, the older cars had seals for cooling go bad before the bearings. Coolant systems appear to be the biggest issue with EVs so far. Most early EVs in the USA were sold in California and in places with temperate climates. There are lots of reports of the i4 coolant valve issue. They are an issue with early ICE vehicles too.

 

[F1Geek]

impossible to guess lifetime of a slip ring without a lot of info on material and manufacturing process. Slip rings are in alternators. They last from 60K miles on a GM to 200K miles in a Honda or Toyota. That equals anywhere from 3 Million to 15 million revolutions. Even then, usually the bearings on motors start to go. Depending on the drivetrain gear ratio at even 15 million revolutions, that isn't a lot of miles. With Tesla Model S, the older cars had seals for cooling go bad before the bearings. Coolant systems appear to be the biggest issue with EVs so far. Most early EVs in the USA were sold in California and in places with temperate climates. There are lots of reports of the i4 coolant valve issue. They are an issue with early ICE vehicles too.

Sure. Still, since I am asking about EESMs in passenger EVs from another EU OEM, I think it is possible they may share tech and even suppliers. Just asking…..