What was found
VERY STRONG SMELL, NOT BURNING, MORE OF AN OILY SMELL. THE ODOR STAYED FOR THE ENTIRE FLIGHT. INSPECTED LT & RT ENGS FOR EVIDENCE OF OIL LEAKS, NONE FOUND. RAN LT & RT ENGS INDEPENDENTLY FOR APPROXIMATELY 5 MINUTES, EACH AT DIFFERENT POWER SETTINGS UP TO 65%, NO OIL SMELL EVIDENT. ALSO INSPECTED APU INLET & DUCTING. REMOVED COALESCE BAG & CLEANED, NO OIL RESIDUE EVIDENT. COULD NOT DUPLICATE, ALL ENGS & APU RAN NORMAL. INSPECTED COALESCE BAG IAW AMM 49-10-00.