What was found
OILY BLEED AIR SMELL IN COCKPIT AND CABIN WITH ACM RUNNING. STARTS WHEN APU BLEED AIR IS TURNED ON AND CONTINUES INFLIGHT. AFTER A 1 HOUR FLIGHT WITH APU OFF SMELL WAS STILL PRESENT IN COCKPIT. ****** CORRECTIVE ACTION ***** ACCOMPLISHED VISUAL & BORESCOPE INSPECTION OF APU WITH NO DEFECTS NOTED. ACCOMPLISHED TASK CARD#: TC-680-21-120905M ECS DUCT BURN OUT PROCEDURE AS OUTLINED IN TASK CARD. REMOVED AND REPLACED COALESCER WITH CUSTOMER SUPPLIED PART, PIN: 83237-12, SIN: NIA. IAW: MM CHAP.12-19-00. LEAK & OPERATIONALLY CHECKS GOOD. ALSO CHECKED APU OIL SERVICE, OIL SERVICE CHECKED GOOD. IAW: MM CHAP. 12-20-49, AND ENGINE/SYSTEM MM CHAP. 49-00-00. RAN APU 1 .5 HRS. WITH NO OIL SMELL NOTED, ALSO RAN BOTH ENGINES FOR AN HOUR WITH NO OIL SMELL NOTED.