What was found
WHEN THROTTLES WERE BROUGHT UP FOR TAKEOFF (DURING TAKEOFF ROLL) A NOXIOUS FOUL ODOR ENTERED THE AIRCRAFT THROUGH THE AIR CONDITIONING PACKS. THE CREW AND PASSENGERS BECAME NAUSEOUS. THE FLIGHT CREW DONNED THEIR O2 MASKS AND THE AIRCRAFT WAS RETURNED TO IAH. MAINTENANCE FOUND THE LT ACM LEAKING OIL INTO THE PNEUMATIC DUCTS. THE LT ACM WAS REMOVED AND REPLACED IAW MM 21-51-01. OPERATIONAL CHECKS WERE GOOD WITH NO LEAKS NOTED. A BURNOUT PROCEDURE WAS PERFORMED IAW MM 21-20-02. THE PACKS WERE OPERATED WITH ENGINES RUNNING AT TAKEOFF POWER AND NO FOUL ODOR WAS NOTED. AN EVALUATION FLIGHT WAS CONDUCTED AND NO ABNORMAL INDICATIONS OR ODORS WERE OBSERVED.