As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING A REPOSITIONING FLIGHT, A NOISE WAS HEARD FROM THE BACK OF THE ACFT FOLLOWED BY OIL PRESSURE SLOWLY DROPPING ON 1 OF THE ENGINES. THE CREW ELECTED TO SHUTDOWN THE ENGINE BEFORE RETURNING TO THE POINT OF DEPARTURE WHERE AN UNEVENTFUL SINGLE-ENGINE LANDING WAS ACCOMPLISHED. TROUBLESHOOTING IS ON-GOING.