Mini Cabrio Knocking and Losing Power

Oh man, that sounds rough! Reduced power and jerking are no fun. Have you checked for engine knock or detonation? I had a similar issue with my old Vauxhall, although it was a diesel. It turned out to be related to the fuel quality, causing issues with the engine tuning. Could deposits be messing with your ignition timing, causing pre-ignition? Are you using the correct fuel?

Yeah, I had similar symptoms! The error codes were vague, pointing to general engine issues. Eventually, a mechanic scoped the cylinders and found excessive carbon buildup. He suspected the fuel I was using wasn't burning cleanly, and that was causing the deposits. Honestly, I'd get it checked by a professional. Are you comfortable messing with engine tuning yourself? Because incorrect ignition timing can cause serious damage. Better safe than sorry!

Interesting point about the Vauxhall! Ignition timing is definitely something to consider. How did you diagnose the fuel quality issue in your case? Did you have any error codes stored as well?

Thanks for sharing your experience! I took it to a local shop and they confirmed it was combustion chamber deposits causing pre-ignition. They cleaned it out and did some adjustments. Cost me 425€, but the Mini is running smooth again. No more jerking or smoke. Really appreciate the advice!