What was found
AIRCRAFT WAS GROUNDED: MUSTY SOCK SMELL DURING DESCENT AT 18,000'. FLIGHT CREW DID FUMES REMOVAL PROCEDURE AND FUMES DISSIPATED. MAINTENANCE ACCOMPLISHED SMOKE, ODOR, FUMES TROUBLESHOOTING TASK CARD 26L00021001 AND FOUND THE APU IGV DRAIN WITH SIGNS OF OIL LEAKAGE. MAINTENANCE ACCOMPLISHED BURN OUT WITH TASK CARD 26L00021013 AND PLACED THE APU ON MEL. MAINTENANCE FOUND THE APU OIL SYSTEM WAS OVERSERVICED AND PROPERLY SERVICED IT PER AMM 49-90-00 - MAINTENANCE ALSO FOUND THE APU OIL TEMPERATURE SENSOR LOOSE AND LEAKING OIL -MAINTENANCE REPLACED THE SENSOR PER AMM 49-94-14 *AALA202608146306* - A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED WITH NO LEAKS OR ODORS NOTED.