BMW i8 Transmission Nightmare: Grinding Gears & Limp Mode

Hey there, fellow BMW owner here with a 2015 BMW i3. I faced almost identical symptoms last month. The torque converter issue is definitely serious and needs immediate attention. When my transmission started acting up, I had the same symptoms, limp mode, grinding noise during shifts, and weak acceleration. The diagnostic showed a faulty torque converter lock-up clutch, just like yours. The repair required removing the transmission and replacing the entire torque converter assembly. In my case, the mechanic found metal shavings in the transmission fluid, indicating internal wear. The job took about 4 days to complete because they had to order specific parts and properly flush the transmission system to prevent future damage. I'd strongly suggest not driving the car much in this condition as it could lead to more extensive transmission damage. While expensive, this isn't something you want to postpone. The torque converter is crucial for proper power transfer between the engine and transmission in these hybrid systems. Hope this helps with your decision-making.

Thanks so much for sharing your experience! Really helpful to know that you went through something similar with your i3. A huge relief to hear someone actually fixed this problem. I'm curious, if you don't mind me asking, what did the whole repair end up costing you? And has everything been running smoothly since the fix, or have you noticed any other issues pop up? Just trying to get an idea of what I'm in for both cost-wise and if I should expect any follow-up problems.

Hey again! Happy to update you on my i3 situation. Since my last message, I actually got everything sorted out with the torque converter issue. I took the plunge and had it fixed, cost me 2120 € in total, but honestly, it was worth every penny. The transmission is now working like a charm, no more grinding noises, no more limp mode, and the car's running exactly how it should. The mechanic did a thorough job replacing the faulty torque converter lock-up clutch, and I'm pleased to say I haven't had a single issue since the repair. The car shifts smoothly, acceleration is back to normal, and those warning lights are finally gone. It's been such a relief! If you're still on the fence about getting it fixed, I'd definitely say go for it. Sure, it's not a cheap repair, but it's way better than risking more damage to the transmission. Plus, being able to drive without constantly worrying about the car acting up is priceless. These hybrid systems are pretty complex, so getting it fixed properly the first time is crucial. Let me know if you need any other info! Always happy to help a fellow BMW owner.

Thanks for the detailed follow-up! I actually bit the bullet and took my i8 to get fixed last week. What a relief to have it sorted! Similar to your experience, my mechanic found metal debris in the transmission fluid, which explained all those grinding noises. The final bill came to around 2300 €, a bit more than yours but not as bad as I'd feared. The mechanic was really thorough and even showed me the worn-out parts they replaced. Had to wait five days for all the work to be done, but it was totally worth it. Took it for a proper drive yesterday and what a difference! No more grinding, the acceleration is smooth again, and those annoying warning lights are finally off. You were right about getting it fixed properly the first time, definitely saved me from bigger headaches down the road. Really appreciate you sharing your experience, it gave me the confidence to get this sorted before it turned into something worse. Cheers!