What was found
NOXIOUS ODOR FROM PACKS NOTICED THE ODOR DURING ENGINE STARTS. AFTER AIR CART WAS REMOVED ODOR WAS STILL PRESENT. APU PNEUMATICS WAS DEFERRED. FLIGHT CONTINUED ON TO SDF. RAN PACKS W/GROUND AIR CART THEN WITH APU AIR. NO ODOR NOTED. INSPECTED PACK DUCTS & BOTH ENG DUCTS NO EVIDENCE OF OIL IN PNEUMATIC SYSTEM. RAN BOTH ENG'S AND PACKS NO NOXIOUS ODOR FOUND. SUSPECT ODOR ELIMINATED BY NUMEROUS PACK CHECKS. OK TO CONTINUE IN SERVICE.