What was found
AC DEPARTED, RT ENGINE LOST OIL PRESSURE DURING CLIMB. ENGINE OIL PRESSURE WARNING LIGHT CAME ON AND ENGINE RPM STARTED TO FLUCUTATE AND EGT WENT TO 750 DEGREES (C). RT ENGINE STOPPED AND FEATHER WAS PULLED AND ENGINE SHUT DOWN. AC RETURNED TO DEPARTURE WITHOUT FURTHER INCIDENT. ON INSP RT ENGINE NACELLE WAS COVERED WITH OIL. LINE TO PROPELLER GOVERNOR HAD CRACKED CLOSE TO FITTING END GOING TO PROP GOVERNOR. THIS RESULTED IN LOSS OF OIL, OIL PRESSURE AND OVERTEMPING ENGINE. SAME LINE WAS CAUSE OF AN EARLIER OIL LEAK, WAS REPLACED WITH NEW LINE AT THAT TIME. EXCESSIVE ENGINE VIBRATION IS SUSPECTED. PROPELLER BALANCE WAS 13, WITHIN EXPECTABLE LIMITS. ENGINE WAS REPLACED AND AIRCRAFT RETURNED TO SERVICE.