Sukha Soma Group

That horrible metallic buzz from the back of the car when I start it up in the morning is finally getting to me, it's been happening for months but I kept hoping it would magically fix itself which was wishful thinking I know. From what I understand it's the valve in the driver's side exhaust flap that opens and closes depending on the drive mode, and the spring mechanism inside gets worn out over time causing it to vibrate like crazy when the engine is cold and idling higher. Once the revs drop it goes back to normal and the car sounds great again especially in sport mode, but those first ten seconds echoing through the underground parking are genuinely embarrassing. I've seen people online say you can just unplug the flap actuator with the valve in the open position or even weld it permanently open, but I don't want to lose the quieter cold start behaviour in comfort mode which was kind of the whole point of having the flap in the first place. I was thinking of visiting a BMW Garage to see if they can just replace the actuator or the spring assembly rather than the entire rear muffler section which the dealer would probably push for. Anyone else sorted this rattle without going full aftermarket exhaust or permanently deleting the flap.