[duplicities]

Wondering if my 2009 335i X-Drive has some bad injectors.

Symptoms:
Cold start misfire
After a few minutes, as car is misfiring hard, if I turn the car off, wait 15 seconds, then turn it back on it no longer misfires
DME code for misfire on basically every cylinder
White smoke out of exhaust
Almost evident that car isn't putting out full power, has almost decreased over time
Was forced to drive the car while it was misfiring twice (before I figured out if I "reset" the car it will stop), and once I shift into second gear (car is auto but driven in steptronic) and hit ~3k rpm, the car dropped into limp mode. When finally stopped, the misfires were horrible and the car's shakes were violent.

Have already replaced spark plugs and coils, as that was first idea. Just had a walnut blast, index of injectors is 5 or 6. Misfire still has not gone away. Is this more than likely my injectors? Is the best option to just buy a set of index 12's?

[madmantwo]

Yeah sounds like a classic case of leaky injectors. One thing I've heard you can do is log AFRs after you let off the gas; this should immediately jump to some very high number (no fuel ideally) for both banks, but if you see noticeable differences between banks or see the numbers slowly increasing then it can be a confirmation of leaky injectors. Note: I've never tried this, and if you don't see this behavior then it does not rule out injectors as being the culprit

[seepete753]

Definitely sounds like injectors. Take off engine cover and coils, pull spark plugs one by one and check for a plug soaked in fuel or fouled (covered in carbon). That is the offending injector if you find a plug like that.

I have a 2010 and I have an extended warranty on my injectors for 10 years/120k miles. If you're​covered, BMW will replace for free, if not pay an Indy shop near you to install it.

I just had the same happen to me 2 weeks ago so I feel your pain. Good luck with the car