As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) THE ACFT HAD TO LAND BECAUSE OF LOSS OF ENGINE POWER AND HIGH VIBRATION. A STUCK VALVE AND BENT PUSH ROD WERE FOUND ON LT REAR CYLINDER (ENGINE WAS ON-CONDITION). CUSTOMER DECIDED TO REPLACED THE ENGINE, WITH AND O/H ONE. NO DAMAGE TO AIRCRAFT.