My Injector problem turned out to be Carbon
Thought I should share my experience, since it seems similar to others. Keep in mind that I still love the car and except for the numerous recalls and a few minor annoyances, the first 47k miles were a great experience. The last 6 months have me struggling with the decision to keep the car. I have made no mods to the car, it is stock.
I started having the same injector problem about 6 months ago @ 47k; only it kept throwing the code for injector 4. When the code showed up for the first time, they struggled for a week to get the SES light to stay off. Bottom-line, the first two 2 times, I was told they replaced the injectors and got the codes to reset (although I always got the sense that they were not sure injectors were the problem).
My most recent code/SES light showed up a few weeks before Christmas with about 54k miles on the car. I did not purchased the extended warranty, so I went into the BMW dealer ready for some resistance to cover this repair. Once I pointed out that the code was the same as two of their prior repairs, they stepped up almost immediately to say they would get it covered.
At that point, they opened up a PUMA case and worked with BMW to correct the problem. It was determined my issue was carbon buildup on the intake manifold, valve cover and valves. Based on the finding, BMW replaced the Intake Manifold and did a Carbon cleaning for the valve cover and valves. The carbon cleaning, which was sublet, was done with walnut shells. The carbon removal appears to have done the trick. The SES Light is off and the car runs better and performs at a higher level than I remember. Once again, itís a joy to drive. I am getting a burnt charcoal/oil smell through the ventilation system when the car is hot and idling at a stop. I think itís from the carbon cleaning splashing down the engine and burning off. Iím sure BMW will remedy this. Since the repair took 3+ weeks, the dealer serviced (Changed the oil and filled the Def) for free.
My concern is that they told me they currently have no known way to prevent the buildup from occurring again. Although the codes didnít show up until 47k miles, I believe it affected performance long before that. I have to believe that buildup will only be faster the second time around.
I do have one other problem. Because of the situation above, Iíve half-heartedly started looking for a replacement. I canít find anything I like nearly as much.