Originally Posted by weasel56

As while the idle control valve can act like a vacuum leak, the part you just described is the "DISA flap" and controls the variable intake runner legnth system. The idle control motor is the same one used in other BMW models, the lil silver can just above the throttle body.

culthero, also check the smaller branch of the intake boot to the throttle body/idle control, it has a habit of cracking in the turn giving unmetered air to the system. And check the "cyclone valve" crankcase vent valve. It is under the intake. With the engine running rough at idle, use a can of throttle body cleaner with the red tube and spray down areas you suspect for vacuum leaks, the engine will smooth out and idle higher when the leak is sprayed.