What was found
RETURNED TO GATE FOR ODER AFTER STARTING NR 1 ENGINE. SUSPECT ODOR CAUSED BY ENGINE WASH PERFORMED THE PREVIOUS NIGHT. PILOTS REPORTED SMELLING ODOR WITH BOTH ENGINES RUNNING AT 40% N1. PERFORMED CONDITIONAL INSPECTION FOR ODOR PER AMM 05-51-26-800-801-C1. RAN BOTH ENGINES AT IDLE. AFTER TURNING ON ALL BLEED SOURCES AN OILY SMELL WAS PRESENT FOR APPROX 30 SECONDS THEN DISAPPEARED. PERFORMED OIL CONTAMINATION REMOVAL FROM PNEUMATIC SYSTEMS PER AMM 21-00-01-100-801. ACCOMPANIED PILOTS FOR MX TAXI AND DURING HIGH POWER RUN FOUND ALL ODORS TO DISSIPATE. RECIRCULAT.