As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED A SMOKE SMELL IN THE AFT PORTION OF THE FUSELAGE. ON INVESTIGATION THE MECHANIC FOUND THAT OIL HAD SEEPED INTO THE BLEED AIR CABIN HEATER SYS. WHEN THE HEAT FROM THE BLEED AIR HEATER WARMED THE OIL IN MADE A SMOKE SMELL.