What was found
AIRCRAFT WAS NOT GROUNDED: PASSING THROUGH 10K FT, SMELLED AN OILY MUSTY ODOR, AFTER LANDING & AT THE GATE THE ODOR INTENSIFIED. APU TURNED ON AFTER LANDING & ODOR OF OIL/MUSK INCREASED MORE. AFTER OPENING DOOR, ODOR DISSIPATED, BUT REMAINED AFTER DOOR REMAINED OPEN. CLEANING CREW & GATE AGENT ALSO SMELLED DIRTY OIL/SOCK ODOR AFTER BOARDING. MAINT FOUND APU OIL COOLING FAN WAS LEAKING OIL & REPLACED IT PER AMM 49-52-51. MAINT FOUND APU GEABOX VENT LINE HAD EVIDENCE OF COKING & REPLACED IT IAW AMM 49-26-54. (AALA202511075785) MAINT ACCOMP DECONTAMINATION OF THE ENVIRONMENTAL CONTROL SYST ACCOMP PER TASK CARD 26L00021014. A SATISFACTORY LEAK / OPERATIONAL CHECK WAS ACCOMPLISHED WITH NO ISSUES OR ODORS NOTED.