What was found
SMOKE DETECTOR ALARM FORWARD GALLEY. DEBRIEFED CREW, STATED WITNESSED SMOKE IN COCKPIT, REFERENCE LOG PAGE 703-6941 ITEM 3 NR 2 AND 3 ACM COALESCER BAG CONTAMINATE WITH ENGINE OIL. COMPLIED WITH FOWARD GALLEY SMOKE DETECTOR OPERATIONS CHECK, IAW 747 AMM 26-13-01. INSPECTED LAVATORY FIRE EXTINGUISHER AND TEMPERATURE INDICATOR, IAW 747 AMM 26-27-00. NO DEFECTS NOTED. COMPLIED WITH SMOKE OR FUMES IN CABIN CONDITIONAL INSPECTION CHECK, IAW 747 AMM 05-51-56/FIM 21-00-810. FOUND NR 4 ENGINE OVER SERVICE WITH ENGINE OIL AND NR 2 AND 3 ACM COALESCER BAG CONTAMINATED. REMOVED AND REPLACED NR 2 AND 3 ACM COALESCER BAG, IAW 747 AMM 21-51-05. OPERATIONS CHECK NORMAL. NO DEFECTS NOTED.