[amstellt]

My wife experienced same issue on 2011 135i DCT. Bought the car used with 26K miles this past Jan. In June, needed to turn on AC and lo and behold...fluctuating RPM during idle only and occassionally stall. Took car into dealer. They said no codes were showing up and could not replicate. They did replace my radio (LCD display was pixelating after parking in 85+ F temperatures for a while, upon restart). The next day, it stalled twice and I took it into the same dealer. On the customer service survey from the first visit - I bitched and moaned saying the car was unsafe and almost being rear ended on several occasions. They reflashed software and attempted 2 additional software versions to no avail. This attempt took 1 week. Finally, dealer called and said BMW NA is currently working on a new software that should be released in mid-July. Long story short, I got the car back July 25th (5 weeks total) and the issue seems to have been resolved. The car now steadily idles at ~800 rpm (as opposed to 300 - 1400 rpm range). I'd take the car in ASAP and demand the new software revision. Hope this information helps you and other 135i owners.