As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) CREW REPORTED THAT WHILE IN CRUISE FLIGHT, IT SEEMED LIKE THE NR 3 ENGINE OVERSPEEDED, THEN DE-COUPLED AND RE-COUPLED AGAIN. PROPELLER RPM READ 107 - 110 PERCENT. MAINTENANCE REPLACED THE NR 3 PROPELLER VALVE HOUSING, ACCOMPLISHED GROUND RUNS, AND THEN RETURNED THE AIRCRAFT TO SERVICE. (TC NR 20091214010)