I have a 2013 R56 naturally aspirated and love my little car, but cant seem to solve the surging cold start idle. When I first got the vehicle, at around 30k miles, it had no problems until it got cold outside. It would surge up and down for about a minute and then idle perfectly. If you drove it within that minute or two, the car would jerk.

I lived with it by letting it warm up, but now that it has 40k miles its getting worse. I did the seafoam treatment everywhere with no help. I changed the spark plugs, and even though they looked pretty worn, no help with new iridium Bosch ones.

Ive had idle issues in the past with BMWs and the idle issues were always fixed by replacing the air control valve. Not familiar with the R56 systm so I dont know if it has a separate air valve or if everything air related is in the throttle body. I always use 89 octane and the thing runs like a beast, but the cold start surge is a pain.

I have checked and nothing pending.