Problem with Range Extender

[i3Christina]

Hello to fellow i3 lovers!
I’m so glad to find this group. My 2017 BMW i3 REX with 36,057 mi, is in the shop at BMW because the Range Extender will not start charging the battery when it reaches 5% charge, so the car stops running. BMW will charge $18,423 to replace the generator!

Has anyone else had this happened with the Range Extender?
Thank you for any advice!

 

[alohart]

I’m so glad to find this group. My 2017 BMW i3 REX with 36,057 mi, is in the shop at BMW because the Range Extender will not start charging the battery when it reaches 5% charge, so the car stops running. BMW will charge $18,423 to replace the generator!

A bad REx engine isn't the only reason why this might happen. If the battery management system hasn't calculated the battery pack's charge level correctly, the battery pack could run out of power before the REx engine turns on. This has happened to some REx owners. A recalibration of the charge level can fix this problem.

Can your REx engine be started in emissions mode? If so, it probably doesn't need to be replaced. Even if it doesn't start, there can be repairs that don't require the expensive replacement of the REx engine.

 

[i3Christina]

Thank you so much for your advice since i3s are not that common in this area, and I am having difficulty getting good service from BMW.

Here is the history prior to reaching out to you. The dealership determined:
- Cylinder #2 misfired
- Replaced ignition coils and spark plugs
- Compression was good at 270 psi
- No metal found in oil
- Torsion shaft needed to be replaced, but this didn’t fix the problem. They said that the REx sounded bad, so the REx would need to be replaced at a total cost of $18,423 for all parts and labor.

Below are 2 sets of questions that I have sent just to the dealership.

Torsion Shaft Questions:
1. Was it bad?
2. Can you show me what was wrong with it?
3. How did they determine that the internal combustion engine needs replacement, in addition to the torsion shaft? (Was it put back together to determine this?)
4. Currently, is the torsion shaft and engine installed?

Additional Questions:
1. Was the recalibration of the charge level performed?
2. Were you able to start the REx engine in emissions mode?

Alojarte: I will be relieved if this solves the problem!!
Thank you once again for sharing your knowledge of i3s with me and other i3 owners!

I will keep you posted on how it turns out.

With deep gratitude,
i3Christina

 

[nickp]

Hello to fellow i3 lovers!
I’m so glad to find this group. My 2017 BMW i3 REX with 36,057 mi, is in the shop at BMW because the Range Extender will not start charging the battery when it reaches 5% charge, so the car stops running. BMW will charge $18,423 to replace the generator!

Has anyone else had this happened with the Range Extender?
Thank you for any advice!

Are you in CA or any CARB state?

 

[i3Christina]

Unfortunately, here in the Midwest, I’m not in a CARB state. (I had to look it up to learn what this is, and which states are CARB states.) Looks like something to work toward!

 

[iain]

You need to give more information. Is the miss fire strictly on one cylinder? These are very very very simple engines. What codes (exactly) has the car stored in relation to the rex?

 

[jfran2]

Even if it does turn out to be catastrophic failure of the REX engine, I would start looking for an independent mechanic who would be willing to do an engine swap. A quick look at eBay shows several used REX engines from around $1400 on up. This would still be an expensive repair, but shouldn't be anywhere near $18,000! I don't know what (if any) BMW coding would be required with an i3 engine swap, but maybe some knowledgeable person on this site might?

John Francis
Rolla, MO

 

[i3Christina]

You need to give more information. Is the miss fire strictly on one cylinder? These are very very very simple engines. What codes (exactly) has the car stored in relation to the rex?

“Cylinder misfire on #2” is what the service person replied.

Thank you!

 

[i3Christina]

Even if it does turn out to be catastrophic failure of the REX engine, I would start looking for an independent mechanic who would be willing to do an engine swap. A quick look at eBay shows several used REX engines from around $1400 on up. This would still be an expensive repair, but shouldn't be anywhere near $18,000! I don't know what (if any) BMW coding would be required with an i3 engine swap, but maybe some knowledgeable person on this site might?

John Francis
Rolla, MO

Thank you for the encouragement! So far I haven’t found an independent mechanic who can take on this project in the WI area. Luckily I have a nephew who is studying to become a mechanic, and he is willing to see what he can do as a learning experience, as he finds time.

I welcome any further advice. It’s good to know that there are i3 owners out there who are able keep their i3s running strong!

Thank you!
Christina

 

[Marty]

Even tho you replaced the coils,are you getting a spark at each coil? If yes, I would check fuel injector function. The good thing at least,you have good compression so no major issues.

 

[iain]

Get yourself a cheap code reader and a free copy of incardoc pro and read the codes off directly.

If its a single cylinder missfire its likely a spark plug, coil, or injector, edge cases would be a gasket failure on the inlet manifold seal on that cylinder. But I would check the codes myself

 

[cpallenjr]

a common troubleshooting step is to swap the coils arounf=d to see if the problem goes with the coil or stays with the cylinder. Could be a spark plug, or a faulty wire or cap,