As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA - AFTER ENGINE START, A OIL LIKE ODOR WAS NOTED COMING FROM THE BLEED AIR SYSTEM. ODOR DISSIPATED AFTER TAKEOFF. ENGINE WAS INSPECTED FOR LEAKS, NONE NOTED. RAN ENGINE THROUGH NUMEROUS POWER SETTINGS, NO ODOR NOTED. COULD NOT DUPLICATE DISCREPENCY. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE.