Quote:
Originally Posted by Stück
Not true, some 535i's do have vacuum actuated exhaust valves.
Cold start sound has little to nothing to do with the position of that valve however, and more to do with whats being done to rapidly heat the catalyst.
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Do you have any more info?
I just picked up a '12 535i. Has BMW M Performance exhaust. On any cold start I get a rattle that sounds JUST like my old 335i flap did on start up, basically sounds like the flap isn't fully open or closed and fluttering. But through all of my research I can't find a solid answer on whether they even have valves or not?!?!
