What was found
(CAN) IN CRUISE, FLIGHT CREW RECEIVED A STEADY NR 2 ENGINE OIL PRESSURE WARNING MESSAGE AND OBSERVED A FLUCTUATING OIL PRESSURE. THE ENGINE NR 2 PROPELLER WAS FEATHERED AND THE OIL PRESSURE DROPPED EVEN MORE. THE ENGINE WAS SHUTDOWN AND AN EMERGENCY WAS DECLARED. THE ACFT LANDED WITHOUT FURTHER INCIDENT. UPON ARRIVAL THE ACFT WAS REMOVED FROM SERVICE. VISUAL INSPECTION OF THE ENGINE OIL LEVEL REVEALED THAT 5 QUARTS OF OIL WERE MISSING. DURING TROUBLESHOOTING, A LEAK WAS NOTICED AT THE BEARING 6 & 7 SCAVENGE TRANSFER TUBE. TRANSFER TUBE ASSOCIATED SEAL RING AND GASKET WERE REPLACED WITHOUT SUCCESS. DECISION WAS TAKEN TO REPLACE THE ENGINE.