As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) NR 2 AND NR 4 CYLINDER VALVES WERE NOT OPERATING, INVESTIGATION FOUND THE FRONT CAM LOBES WERE MISSING. THE CAM WAS REPLACED AND SO WERE THE NR 2 AND NR 4 CYLINDERS. THE ENGINE WAS RETURNED TO SERVICE. AFTER 77 HOURS OF OPERATION, THE REAR CAM LOBES WERE WORN AWAY. THE ENGINE WAS REPLACED AND SENT FOR OVERHAUL.