Question on misfire

[spinelli911]

Will you get a light, if the engine misfires or only if multi misfires or not at all? whats the deal?

[Mayorchuck]

If the DME detects a misfire on a cylinder, it will stop sending juice to it and yes, it will generate a code.

[spinelli911]

I cant tell if my engine is misfiring or not. I dont have any engine lights or any lights at all indicating any issues thus the original question.

[David325e]

Time to get into the details then.

What symptoms are you having that made you think of a misfire? How does it drive, idle, engine speed at idle, mpg's, how many miles, how long have you had it, and what have you replaced?

[Mayorchuck]

I cant tell if my engine is misfiring or not. I dont have any engine lights or any lights at all indicating any issues thus the original question.

You asked if you would get an engine light if you have a misfire. Thus my original answer.:D

[spinelli911]

If the DME detects a misfire on a cylinder, it will stop sending juice to it and yes, it will generate a code.

Hey sorry wasnt sure what "DME" ment

[Mayorchuck]

No worries, just messin'. As David stated, need more info to help further.

[spinelli911]

Time to get into the details then.

What symptoms are you having that made you think of a misfire? How does it drive, idle, engine speed at idle, mpg's, how many miles, how long have you had it, and what have you replaced?


Ive had it 1 year, 60,000km(KM not miles) one owner dealerservice its entire life. Its been puttering/knocking/banging/serging (not sure what to call it) at idle, it drives like new, just at red lights or parked or what not, when ever at idle its doing it and they smoke tested it, not vac leak or anything, just did the spark plug, and last week did a fuel injector clean and it was better for a day or two know its back. its misfired the other day and they said do the injector clean so i did, and they said drive it 1000km before I bring it back but its back to the way it was before when it misfired and I just dont want to drive it for another month or so (1000km) then find out i should have an need a new engine, cause of some dumb bmw service guy who didnt advise me correctly, so right now I just am not sure what to do.
Im gonna take it back tomorrow and get some paper work and they maybe bring it to an indy or something. I have no idea. Ive had it 11 months and have spent 11k on service At this point i dont even want to look at the car I just want it fixed or gone. I have a 2011 750il and bought this cause I like it when it came out just couldnt afford it and now Im spend more to keep it on the road than a new M5 would being track driven. IM PISSED!!!! any input is much appreciated

[Mayorchuck]

MAF or Cam position sensor comes to mind as they don't always throw a code when they go bad. You can try unplugging the MAF and then start it up to see if it changes. Could also be clogged cats but I would think you would notice a loss of power while driving.