Rough Idle and Start-Up on BMW e81: Fuel Injector?

[DMGRS]

Hi everybody, Last night I was going home when my vehicle abruptly lost all power and I had to have it towed. After a restful night at home, I checked on my vehicle early the next morning and discovered that it starts but has a harsh initial idle before settling down. Seems to vibrate when accelerated (video link added below). I performed a basic running test with ISTA and noticed that cylinder 2's fuel readings were significantly different from the others (picture).

I'm not sure what the problem is, but I removed the injector and it still ran the same, so I'm keeping my fingers crossed that it's just that. I'm crossing my fingers that it isn't rod knock.

 

[DMGRS]

Initiation and acceleration.

[HOV]

It's not a good look for no. 2.
If the injector pipe is unscrewed, does fuel spill out the top?

[Doncaster34]

This noise reminds me a lot of diesel knock, however a few years ago on my N47 I discovered it was the fourth large end. It sputtered because the large end had so much play, throwing off the timing on that cylinder.

I would try removing the injector from cylinder 2 and plugging it into cylinder 1, starting the engine again, and reading the injector readings to see if they change.

[DMGRS]

We conducted a test with the injector for cylinder 2 disconnected, and it performed identically to how it did in the video. Since that knock sounds much worse than normal, it's hard to tell whether it's simply an injector.

[vitessear3]

It's impossible to provide a definitive diagnosis from a video, but I'd say it was a bottom end knock. Is there a rap on the overhang?

[DMGRS]

We replaced the injector, but the vehicle still has a harsh, banging idle. We drained the engine oil and discovered metal fragments in the oil filter. It seems to be junk today because to the high probability of a rod knock.

[Doncaster34]

Given the presence of noise and metal fragments, it seems likely that the large end is no longer functioning.

[HOV]

RIP e81.