As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
COCKPIT ODOR OIL SMELL - WHEN SELECTING HEAT ON DURING CRUISE FLIGHT, THERE WAS AN OIL SMELL IN THE COCKPIT. WHEN SELECTING HEAT OFF THE OIL SMELL DISAPPEARED. REPLACED COALESCOR SOAK RAN APU AND ENGINES. OPERTION CHECK GOOD REF CESZOKMM 21-51-00