BMW i3 Hybrid Transmission Issues: Warning Light & Grinding

Hi there! I had a similar issue with my 2020 BMW i4 Hybrid last year. I've got some experience working on cars, but transmission issues are definitely out of my comfort zone. The symptoms you're describing sound exactly like what I faced. After taking it to my trusted workshop, they found the gearbox oil level was too low, which was causing those grinding noises and the warning light. The total repair cost me 365 Euro, including labor and fresh transmission fluid. Before going further, could you share: Current mileage on your i3? When was your last transmission service? Any other warning lights showing up? I also own a BMW 330e, so I'm quite familiar with their hybrid systems. Let me know these details, and I might be able to help more specifically. Best regards

Hey, thanks for your detailed response! My i3 is currently at 172,986 KM and had its last service about 4 months ago. Actually, no other warning lights are showing up, just the transmission one, which is what made me think it might be the pressure sensor specifically. The grinding noise is definitely concerning, though. Good to know about your experience with the oil level issue. The price you mentioned sounds way better than what I was expecting. Might be worth checking the fluid levels first before assuming the worst. Did your car also make that grinding sound specifically during gear changes, or was it more constant?

Hey again! Thanks for the follow-up. Yeah, in my case, the grinding noise was definitely most noticeable during gear changes, especially when shifting from 2nd to 3rd. It's interesting that your symptoms match mine so closely. With my i4, the noise started pretty subtle but got worse over time. Since your last service was only 4 months ago, I'd be surprised if it's just a fluid level issue like mine was. But it's still worth checking, sometimes these hybrids can be a bit thirsty with transmission fluid, especially if there's a small leak somewhere. You know what's weird? After I got mine fixed, I spoke with another i4 owner who had almost identical symptoms, but in his case, it actually was the pressure sensor. Cost him a bit more than my repair, around 850 Euro if I remember correctly. But at least it wasn't a complete transmission rebuild! I'd suggest getting it checked soon though. These transmissions are pretty robust, but you don't want to risk any further damage. When I waited around with mine for a couple of weeks, the grinding definitely got worse. By the way, how's the shifting in cold conditions? Does it seem worse when the car hasn't warmed up properly? Just trying to help narrow it down based on what I experienced!

Thanks so much for all this information! You've actually made me feel a lot better about the whole situation. The grinding is definitely worse when the car's cold, now that you mention it. I've noticed it's particularly bad during the first 10 minutes of driving in the morning. Actually, I just checked my service records, and they didn't specifically mention checking the transmission fluid during the last service, so that could definitely be the culprit. I think I'll book it in for next week, asking them to check both the fluid levels and the pressure sensor. Rather catch it early than risk more damage, especially after hearing about your experience. The price range you've mentioned gives me a good idea of what to expect too, anywhere from 365 to 850 Euro seems much more manageable than what I was imagining! Really appreciate you taking the time to share your experience. It's definitely helped me understand what I might be dealing with. I'll make sure to get it sorted before it gets any worse. Thanks again for all your help!