As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON TAXI OUT VERY STRONG FUMES NOTED BY CAPTAIN AND F/O. APU WAS OFF ALL 3 ENGINES RUNNING WITH PACKS 2, 3 ON (1 DEFERED) RETURNED TO GATE CLEANED AIR DUCTS OF ODOR IAW MM 21-53-00-7. OK FOR SERVICE. REMOVED ALL 3 WATER SEPARATOR COALESCERS FOUND. LUBE IN EACH SPRING MECHANISM, CLEANED ALL RESIDUE AND CHANGED ALL BAGS. REINSTALLED MM 21-53-03-2-0. PACK BURN IN PROGRESS, CLEANED AIR DUCTS OF ODOR IAW MM 21-53-00-7. OK FOR SERVICE. FINAL CLOSED.