Hi folks,
Hoping for a friendly steer on this one. Just purchased a 2017 520d M-Sport touring. Almost every time I start it, after a few seconds there is a louder high pitched rumbling noise coming from the exhaust. It lasts for about 5 - 10 seconds and the stops and it does happen occasionally after that but never when driving on a long run. This is happening daily. I have attached a video which I took a few seconds after I pushed ignition from cold one morning. The car drives great but this is annoying and not something I ever experienced with a 2015 520d I owned up to a few years ago. I have it booked into a local garage next week.
IMG_9794.MOV