Ditto. When my 5 speed was doing it, we thought that we could hear an audible "Tick" noise coming from the engine bay when it would have an erratic idle. The local BMW shop suggested that the ticking noise could be an injector hanging up, or a coil pack going bad. But one of the employees there said to check vacuum first. And it only did it on chilly mornings with a cold start.

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Running:
2001 E53 3.0i Black 5MT Style 87, Eibach Swaybars, Headers, Turner Monoball Bushings, Oil pump nut fix, E60 short shifter + ZHP shift knob, Sport Swap 204K (G-power supercharger coming soon)
2011 E70 35d Blue Style 214 3" exhaust, Dudmd stage 2, 2" HR lowering springs
2012 E70 35d Black Style 215

Sold:
2002 e39 540i 6MT Black sport, M5 LSD, M60 Intake manifold
2003 e39 525i Auto Grey Sport