I just did the rod bearings on my 09 115k mile m3.
I removed both engine belts with anticipation of replacing them, but could not find belts locally so i threw on original pulleys and belt.
The car runs great but on engine shut off, 5-8 seconds later very consistently there is a singular clink noise.
I also have the code: P1748
Here is a link to the audio file:
https://file.io/uuTwBxIgINY4
Any thoughts what this could be?