As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT CREW REPORTED AN OIL ODOR IN AIRCAFT THAT WAS CAUSING HEADACHES WHILE THE AIRCRAFT WAS AT THE GATE. AIRCRAFT GROUNDED. MAINTENANCE FOUND THE APU OIL HAD BEEN OVERSERVICED, DRAINED OIL SYSTEM TO PROPER LEVEL AND ACCOMPLISHED A SATISFACTORY OPS CHECK WITH NO ODORS BEING NOTED.