As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: DURING ALL PHASES OF FLIGHT, DIRTY SOCK SMELL ON AND OFF IN CABIN AND FLIGHT DECK, VERY STRONG ON TAXI IN. MAINTENANCE REPLACED THE APU OIL COOLING FAN PER AMM 49-52-51 AND ACCOMPLISHED A SATISFACTORY LEAK / OPERATIONAL CHECK.