BMW i3 Transmission Grinding: Common Sensor Issue?

Hey there! I had very similar issues with my 2017 BMW i8 Hybrid at around 155k km. Started with rough shifts and grinding, followed by warning lights and limp mode. Initially thought it was just a sensor too. Turned out my gearbox oil level was critically low, causing overheating and poor lubrication. The transmission was essentially struggling to function properly. The main symptoms were identical to yours, grinding, rough shifts, and warning lights. Got it checked at a shop, they found a slow leak from one of the transmission seals that had been draining oil over time. While it was a serious issue that could've damaged the transmission permanently, catching it early prevented major damage. The fix involved replacing the faulty seal and doing a complete transmission fluid change. My advice would be to get it checked ASAP before any permanent damage occurs. These symptoms shouldn't be ignored, as they can lead to complete transmission failure if left untreated. Best of luck with the repair.

Hey, thanks for sharing your experience! That sounds exactly like what I'm dealing with. Really helpful to know about the transmission seal leak, I'll definitely get that checked out first. Quick question, do you remember roughly how much you ended up paying for the seal replacement and fluid change? Also, has everything been running smoothly since the repair?

Hey again! Great to hear back from you! Yes, I can definitely give you a cost breakdown. In my case, after seeing the mechanic last week, it turned out to be both the faulty transmission oil temperature sensor AND low gearbox oil, just as I suspected. Total bill came to 365 € for parts and labor, which honestly wasn't as bad as I feared. And you'll be glad to know my i8 has been running like a dream since the fix! No more grinding noises, shifts are silky smooth again, and those pesky warning lights haven't shown up since. It's like having a completely different car. The transmission sensor was the main culprit causing all those warning lights and limp mode issues. Just keep in mind that catching these issues early is super important. I was lucky that no permanent damage was done to my transmission. If you're experiencing similar symptoms, don't wait too long to get it sorted. Let me know how it goes with yours! Always happy to share more details about my experience if you need them.

Thanks for all the detailed info! Just wanted to update everyone on what happened with my car. Took it to a mechanic yesterday and you were spot on! Had both issues, low transmission fluid from a leaky seal and a faulty sensor. Total repair came to roughly 400 for parts and labor, which wasn't too terrible considering I was worried about needing a whole new transmission. The mechanic I found was fantastic, really took the time to explain everything and show me the problems. Had the car back within a day, and wow, what a difference! No more grinding, shifts are perfect, and those warning lights are finally gone. Feels like I'm driving a new car. Really grateful for the advice here. Definitely saved me from what could've been a much bigger headache (and expense) if I'd kept driving it in that condition. Lesson learned about getting these things checked out early! Thanks again for helping me sort this out.