As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER STARTING ENGINE AND PERFORMING A ROUTINE WARM UP. PILOT NOTICED OIL PRESSURE DROPPING. AFTER SHUTDOWN, THE OIL FILTER WAS SHOWN TO HAVE PARTIALITY BLOWN OPEN AT THE BASE WHERE IT IS CRIMPED. ALSO THE PRESSURE RELIEF VALVE WAS FOUND TO HAVE 14 WASHERS UNDER THE SPRING. THIS ENGINE IS NOT ALLOWED TO HAVE ANY WASHERS. THE OIL FILTER HAD 21 HRS SINCE INSTALLATION AND WAS NOT OVER TORQUED. THE ENGINE HAS 1044 HRS. SMOH.