My 2011 750Li gave a Drive Train Malfunction warning the other night. It immediately stopped firing the entire left bank of cylinders. I took it to the dealership and after $2300 in diagnostics they are telling me my timing chain guides broke and the chain jumped a tooth. Apparently, it also bent the valve on the number 8 cylinder. The dealership is quoting over $15,000 for the repair. What I'm wondering is would a stretched timing chain cause something like this? I had the CCP done in June and they said the timing chain was ok. Has anyone else had timing chain issues after the CCP?