Originally Posted by Radiation Joe
My guess is you have about 20k to 25k miles on the car. Replace the spark plugs and it will fix it right up. I'm on my second e90 and both have had this behavior, especially when cold. It got worse until around 30k miles when the plugs were replaced. After that it was fine.
Just want to report back here. Joe was right on, after replacing all plugs(tips worn out), the idle is so much smoother, huge low end power gain, very solid acceleration when I floor it at 1500rpm, cold or warm.
everyone should test their low end performance at 25000 miles, change your spark plugs if any of the above symptom exists.