As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: ON APPROACH SMELLED OIL/FUMES IN FLIGHT DECK. MAINTENANCE FOUND OIL COMING FROM THE APU LOAD COMPRESSOR DRAIN CAVITY DURING THE INITIAL TROUBLESHOOTING . REPLACED APU AND ACCOMPLISHED A SATISFACTORY LEAK / OPERATIONAL CHECK PER TASK CARD 26L31049003.