What was found
(CAN) WE HAD AN INCIDENT WITH IFSD IN FLIGHT. NR 1 PEC CAUTION LIGHT CAME ON. THE NR 1 PROPELLER RPM DROPPED FROM 850 TO 650. A FEW MINUTES LATER RPM STARTED INCREASING AND STOPPED AT 1050. CAPTAIN FOLLOWED QRH AND BROUGHT THE CONDITION LEVER TO START & FEATHER. ENGINE FAILURE/SHUT DOWN PROCEDURE WAS FOLLOWED. CAPTAIN MADE AN ENTRY IN AML PEC CAUTION LIGHT ON. AFTER 4 MIN PROP OVERSPEED TO 1050, SECURED NR 1 ENG, AS PER QRH. DURING RETRIEVAL OF FAULT CODES ON EMU/POWERPLANT FOUND CODES 260, 236, 158 AND 132. MAINTENANCE FOUND PROP HAD TO BE SERVICE WITH GREASE. (TC NR 20180208003).