As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UPON INSPECTION OF OIL FILTER ADAPTER IAW CESSNA SEB 93-1-R1, FOUND FILTER ADAPTER THREADS HAD PIECES MISSING. INSPECTION WAS PROMPTED BY LOOSE RETAINING NUT AND OIL LEAK. THREADS ON THE ENGINE WERE INTACT. REPLACED FILTER ASSY WITH NEW CESSNA ASSY.