[bigez96]

My 2007 328xi is really lucky that it's the best driving car I've ever owned. Something seems to go wrong with it on a weekly basis, but I have a feeling that's just part of owning a 100k mile 13-year old BMW.

Anyways, here's some background on what's going on: I've been having an issue with my car idling erratically for about a year now. When it would get warm, the issue would go away, and it actually managed to stay away almost completely through winter, just showing up a month or so ago. I decided the issue was related to my PCV, as I had all of the telltale signs, including rough idle and a loud whistling sound coming from the engine bay. The only codes I would get were a code indicating I was running lean, which I attributed to my aftermarket intake, as well as a very occasional misfire code from a random cylinder or two. I ordered a new PCV valve back in November, but never got around to replacing it. About a week ago, the problem got so bad that the car would stall whenever dropping under 10 mph, making the car undriveable.

So, breaking the Covid-19 stay at home order, my buddy came over and we did the PCV DIY replacement. Started the car, ran fine, drove perfect. Took the car out again later in the day, and the rough idle started back up again. I will start the car, and it'll get to about 750rpms, and then it'll rapidly bounce between 500 and 1500rpms for about 5 seconds, then it'll settle back down around 750. Then I put it in gear, and it'll bounce up and down a little more, and then I will have no issues the rest of the drive. So, I got home, cleared the check engine light that I usually have, turned the car off, started it back up. It did it's little idling thing, calmed down, no engine light, put it into reverse, the car dropped below 500rpms for a second, and immediately I got a light. Checked the codes, and I had:

• 2D06 - Air-mass system
• 29CD - Combustion misfires, cylinder 1
• 29CF - Combustion misfires, cylinder 3
• 29CC - Combustion misfires, several cylinders

I know I have never had the Air-mass system code, but that might just be from my intake again, I don't know. I took the car out for another drive, and no issues during the drive. I looked over the engine bay and didn't see anything that looked out of place, other than now seeing that the grounding wires from the coils on cylinders 4-6 look like like crap, as the wires look like they've been rubbing on something and look like they're about to break (missing insulation, starting to break and fray), so I will have to take care of that.

If anyone has any ideas as to what I need to work on next, please let me know. I just want a normally running car. Thanks!