A loud cracking noise from the front door power window regulator occurs when opening or closing the right side or left side window. BMW I8(I12) window regulator noise when opening or closing side window.This instruction show you guide on how to solve it.
Faulty power window regulator
Inspect the cable housing of the front power window regulators. The picture shows a good cable housing. No black bushing is showing outside of the cable white housing.
If the inspection of the cables shows damage to the black bushing, and it is extended out of the white cable housing, then replace the affected window regulator. Refer to ISTA repair instructions 51 33 000 Remove and install/replace the power window regulator in the left or right front door.
51 33 7 401 657 Window lifter without motor, front left x1
51 33 7 401 658 Window lifter without motor, front right x1
And more BMW cases please refer to:BMW trouble repair.