As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) PILOT REPORTED HIGH OIL TEMP VERNATHERN REPLACED AND ON GROUND RUN ENGINE RAN ROUGH. LARGE AMOUNT OF OIL NOTED COMING FROM SNIFFLE VALVE MIXED WITH FUEL. SPARK PLUGS REMOVED AND FOUND THOSE REMOVED FROM NR 5 CYLINDER WERE DAMAGED. REMOVED CYLINDER AND FOUND 1/3 OF VALVE FACE (EXHAUST) MISSING. REPLACED CYLINDER AND CHECKED ALL SCREENS AND FILTERS.