so i took my car out of storage on wednesday and today took it to the dealer to do the A service which is basicly a $500 oil change...it was all fine picked up the car drove it around for a while stopped to visit some friends all good, then made one final stop to have a coffee and when i came back and started the car it started to backfire like crazy, and when taking off it hesitates, backfires, but once it gets going its fine....when at a stop light i can feel the engine shaking on my feet....but no CEL

 

Misaligned air filter?

 

Old gas in the tank maybe

 

i filled up on wednesday and i am already half tank down, so i don't think that it would be old gas

 

Any mods?

 

bone stock my friend

 

Without a CEL the dealer wont even know what to do either.. lol

 

Just because there is no CEL doesn't mean there are no codes. You would be surprised how many codes cars show up on DAS. I scanned mine and it showed my roller blind malfunction my navigation disk wasn't reading my CD changer error a light bulb was out my teleaid was outdated. It gets pretty detailed. If his car back fired there is probably something stored. I know these aren't engine related, but it just shows you the dept of the logging the system does. Even if the system is not malfunctioning it still may have a code.

 

+1 My M5 ran fine but I decided to check codes with my Peake reader - 4 codes showed up. Get it scanned...

 

Check your oil level, bet they over filled it. Other members have had rough idle problems with this same issue.

 

^^^^ +1

Easy to do and verify or eliminate one potential source of the problem of a rough idle.