What was found
FUME ODOR ON THE GROUND AT THE GATE WHEN PACKS WERE TURNED ON, SUSPECTED TO BE FROM GROUND EQUIPMENT. ODOR REOCCURRED AFTER TAKEOFF. APU WAS BEING USED AT THE GATE. AFTER PASSING THRU 15000 FT, LT ENG ON LT PACK AND RT ENG ON RT PACK, APU OFF, ODOR IS GONE. REMOVED DUCT AT APU, NO CONTAMINATION. REMOVED DUCT AT LT PACK, NO CONTAMINATION FROM EITHER ENGINE. PERFORMED BURNOUT PROCEDURE IAW MM. AFTER BURNOUT RAN PACK NORMALLY AND DID NOT NOTICE ANY ODORS.