What was found
THE FLIGHT CREW REPORTED A DIRTY SOCK ODOR WHILE THE AIRCRAFT WAS AT THE GATE DURING THE BOARDING PROCESS. THE ODOR STARTED IN THE COCKPIT AND WORKED IT'S WAY TO THE BACK OF THE AIRCRAFT. MAINTENANCE FOUND AN OIL LEAK IN THE APU COMPARTMENT, REPAIRED THE LEAK AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK WITH BOTH ENGINES AND THE APU RUNNING WITH NO ODORS BEING NOTED. CABIN CREW AGAIN DETECTED AN ODOR, DESCENDING THROUGH 10,000 ON ARRIVAL. MAINTENANCE SUSPECT THE APU IS LEAKING OIL FROM THE TURBINE SHAFT.