As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UPON DISASSEMBLY OF THE ENGINE, FOUND BRONZE PLATING UNBONDING AT COMP. BORE. ALSO, FOUND T/M HELICOIL DAMAGED. THE CAUSE FOR BRONZE PLATING UNBONDING IS DUE TO THE SURFACE CORROSION ON HOUSING AND OIL ACCUMULATION. THE CAUSE FOR T/M HELICOIL DAMAGE IS DUE TO METAL FATIGUE IN THE OIL PORTS.