What was found
(CAN) FLIGHT CREW NOTICED SMALL OIL PUDDLE ON RT ENGINE, WIPED & CLEANED. NO SOURCE OF LEAK NOTED. ENG HAD 2.7 HR SINCE INSPECTION EVENT NR 2, COMPLETED. ACFT FLOWN 0,2 HR TO MAIN BASE WITH APPROVAL OF MX. COWLING REMOVED, ENG WASHED & CARRIED OUT ENG RUN, NO LEAK NOTED. 10 MIN AFTER ENG RUN SMALL PUDDLE APPEARED UNDER ENG. AFTER 3 ENG RUNS, PIN HOLE FOUND BETWEEN CYLINDER NR 2 & 4. ENG REMOVED & SENT TO SHOP FOR REPAIR. ENG SHOP FOUND CRACK & REPLACED CRANKCASE. ENG SHOP PROVIDED CRANKCASE PIN AS LT10 540-22BD CC. REPAIR TAG & REPAIR ENTRIES ATTACHED.