zakt

I got something like that going on also on our 08 528i. Ours wont die out yet but no acceleration and turn it off then on is fine. changed the plugs no change I had a code on a misfire on 5 they swapped it to 2 and quit then started again. Im leaning toward coil on ours but haven't verified it.

thomas finlass

Well, I'm lost........do coils not just work or don't work, would a coil problem present itself is this manner...intermitently.....well, it's one of the following...air mass meter, coil issue or injector issue...now which wire to cut, blue, brown or yellow....

pcy

Ignition coils degrade over time.
Humidity in the air can amplify the symptoms with degraded coils.
Depending on the mileage of the car, it may be prudent to replace the coils.

zakt

I replaced the possible coil in question same thing... I even disconnected each coil and started it same problem (not sure that would isolate it but didnt change the problem) going into the dealer in a couple days.

E60I

The harness (plug) that you connect to the ignition coil has three thin wires (they have different colors). Sometimes when you pull the harness out to replace the coil or spark plug, you may have broke the insulator(s). Consequently, it causes a misfire on start up and triggers the Service Engine Light to come on (for mifire issue).

I had this problem and neither the dealer nor and Indy Shop could figure out why. I got lucky with the discovery because I had superman vision at the time. lol

Anyways, I used the heat shrink tube to insulate all three wires and now the SERVICE ENGINE LIGHT (for misfire issue) don't come on at "every start up" anymore. It only come on maybe every 30 days or more because I think I did not do a good job at insulating them.

I hope this help and good luck!