What was found
PRECAUTIONARY SHUTDOWN NR 4 ENGINE DUE TO LOSS OF OIL PRESSURE, ALL OTHER INDICATIONS NORMAL. WINDMILLING OIL PRESSURE STAYED ABOVE 10 PSI. PERFORMED INLET & EXHAUST VISUAL INSPECTION, NO DEFECTS. PERFORMED WINDMILL INSPECTION PER MM 72-00-00 PG 682 W/X 3F (NOTE OIL PRESSURE ABOVE 5 PSI, WINDMILL LESS THAN 30 MINUTES). PERFORMED START PROCEDURE AFTER EMERGENCY SHUTDOWN PER B747 MM 71-00-00-01B. FOUND ALL PARAMETERS NORMAL. TRANSFERRED OIL FILTER AND CHIP DETECTOR TO CI 3155. MUST BE ACCOMPLISHED WITHIN 15 FLIGHT HOURS, A/C RETURNED TO SERVICE. REPLACED NR 4 ENGINE OIL FILTER PER B747 MM 72-61-05 AND INSPECTED CHIP DETECTORS, NO DEFECTS NOTED. RAN ENGINE AT GROUND IDLE, NO LEAKS.