As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) AFTER 2.5 HOUR FLIGHT, PILOT REPORTED OIL PRESSURE CREEPING DOWN DURING DESCENT. GROUND RUN CARRIED OUT AND PRESSURE MAINTAINED AT 70 TO 75 PSI. WHILE COMPASS SWING CARRIED OUT, PRESSURE DROPPED OFF AGAIN. ENGINE REMOVED FOR OVERHAUL. REPORT FROM O/H SHOP STATED THAT OIL PUMP WAS CRACKED INTERNALLY.