BMW 8 Series Engine Issues: Jerking and Power Loss Help

Hey there! I have some experience working on cars and faced something similar with my 2021 BMW 7 Series last year. I initially thought it was a serious engine problem too since I had those exact symptoms, jerking, power loss, and warning lights. Turned out it was messed up chip tuning that I had done at a third-party shop. Had to take it to a specialist who basically reset the ECU and reinstalled the original factory settings. The whole thing cost me around 180 Euro but solved all the issues completely. Before I can share more specifics about your case, could you tell me if you've had any recent modifications or tuning done to your car? Also, what's the exact engine variant of your 8 Series? These details would help me give you more relevant advice based on my experience. The symptoms you're describing sound very familiar, and it's best to get it checked quickly before it potentially causes more problems.

Thanks for sharing your experience! My BMW is completely stock with no modifications or tuning, I'm running it just as it came from the factory. Last service was about 2 months ago at 104078 KM, and everything was perfect until these issues started showing up last week. I haven't messed with any settings or taken it to any third-party shops. That's what makes this so frustrating, it just started acting up out of nowhere. I'm hoping it's something simple like yours was, but since mine's unmodified, I'm a bit worried it might be something else. Did your fault codes give any specific hints about what was wrong when you had your issue?

Hey again! Sorry to hear your BMW is still giving you trouble. Yeah, now that you mention it's completely stock, this does sound different from what I dealt with. When I had my issues, the fault codes were pretty specific about the ECU mapping being the culprit, made sense since I had that aftermarket tuning done. In your case, since it's running factory settings and was fine after the recent service, I'm thinking it might be something with the sensors. These newer BMWs are super sensitive to sensor issues. When my had his 8 Series (same year as yours) at the shop, turned out it was just a faulty mass airflow sensor causing similar symptoms. The car basically goes into 'limp mode' to protect itself when it gets weird readings. Have you noticed if the problems get worse when the engine's cold or after it's been running for a while? With mine, even before the tuning fix, there was definitely a pattern to when it would act up. This might help narrow down what's going on with yours. Also, while I'm not a huge fan of throwing parts at problems, might be worth checking your spark plugs and coils. These can cause unusual misfires that feel exactly like what you're describing. Pretty common issue on our engines, actually. Let me know how it goes, really curious to see what's causing this on your stock setup.

Thanks for the detailed follow-up! Actually, now that you mention it, I've noticed the jerking is definitely worse when the engine is cold, especially during the first 10-15 minutes of driving. The power loss seems pretty consistent throughout though. I called the dealership and managed to get an appointment for next week. I'll definitely have them check the mass airflow sensor and the spark plugs, that's a really good suggestion. Makes sense that it could be sensor-related since everything else is stock and was working fine until recently. I'll update this thread once I get it diagnosed properly. Really appreciate you taking the time to share your experience and suggestions. It's given me a much better idea of what to discuss with the technician when I take it in.