[friedymeister]

Hi everyone,

I just replaced my valvetronic servomotor on my 2011 135i with an N55 engine with 35,000 miles and this sound developed when I turned it on. Any ideas? It changes with rpm

https://drive.google.com/file/d/1uUy...usp=drive_link

No engine related codes, just airflow sensor, which I'm working on.

I felt the fuel rails and noticed that the most significant vibration is at cylinder 1, followed by 2. I tried disconnecting power to injector #1, but I couldn't tell if it eliminated the sound. I did the same for injector #2.

The brand new spark plugs already have a bunch of carbon on the end, is that normal after running the car for less than an hour?

I removed the brand new coil pack and spark plugs and inspected the cylinder with an endoscope and saw crud, but I don't see any destruction.

Video on all cylinders but #1: https://drive.google.com/file/d/1jB3...usp=drive_link

Video on all cylinders but #2: https://drive.google.com/file/d/1JFm...usp=drive_link

Photo of spark plug: https://drive.google.com/file/d/1F8p...usp=drive_link

Photos of Cylinder 1: https://drive.google.com/file/d/18BN...usp=drive_link

https://drive.google.com/file/d/19Qp...usp=drive_link

Photo of Cylinder 2: https://drive.google.com/file/d/1mKc...usp=drive_link

Anyone have other suggestions? Could injector 1 be bad? I can't tell if the sound goes away/gets better when I unplugged injector 1.

Could it be a hydraulic lifter? Should I just rev it a bit to clean out the oil?

Update:
- now misfires on startup that resolve and sound is worse while slighting revving the engine.

https://drive.google.com/file/d/1Fy2...w?usp=drivesdk

Codes:
2. There are now several codes:
29D0 intake air temperature sensor, electrical: short circuit to B+
36FD DME main relay: Implausibly, open
2EFE Combustion misfires several cylinders detected
278D Air mass flow sensor operating range: air mass too low
2775 Air mass plausibility: air mass too low
2EFF combustion misfire cylinder 1 detected
2f00 Combustion misfire cylinder 2 detected
2EE2 misfire several cylinders damaging exhaust gas after starting up
2EE6 misfire cylinder 1 damaging exhaust gas after starting up
2EE9 misfire cylinder 2 damaging exhaust gas after starting up

[fastboatster]

post all of the codes from your N55 subforum thread. These are all engine electricals related codes.

[friedymeister]

I updated the post