As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ODOR IN COCKPIT CABIN WHEN RUNNING PACKS WITH APU. ALSO SMELLED THE ODOR DESCENDING BELOW 10,000. AIRCRAFT WAS GROUNDED. MAINTENANCE FOUND EVIDENCE OF OIL IN THE APU PLENEUM. MAINTENANCE REPLACED APU IAW JOB CARD 26L31049003 AND ACCOMPLISHED SATISFACTORY OPS CHECK.