BMW 6 Series Emergency Mode: Knocking and Power Issues

Thanks for the detailed response! My car's at 60537 KM and just had its service last month. I'm actually noticing these issues mostly when the engine's warm, especially during highway driving. I've been using premium fuel consistently, but the problem keeps getting worse. The smoke is particularly concerning, it's greyish-white and quite visible when accelerating. I'll definitely look into getting the combustion chambers checked based on your experience. The cost seems reasonable if it fixes the problem. Did you have to replace any parts during the cleaning process?

Thanks so much for that follow-up info! I'm really glad to hear the spark plug replacement tip, I'll definitely ask about that when I take it in. You know what's funny? I actually just picked up a fuel system cleaner yesterday, hoping it might help! I'll try that while I wait for my appointment next week. It's quite reassuring that our symptoms match up so closely, same mileage range, similar smoke issues, and especially the warm engine problems. Makes me feel more confident that I'm on the right track with the combustion chamber cleaning. I'll get them to check everything while they're in there. I'll make sure to update you after the service. Really appreciate all your help and detailed explanations, it's definitely saved me some stress knowing someone else has successfully dealt with the same problem. Thanks again for taking the time to share your experience!