As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT ALTITUDE, HEARD LOUD BANG FOLLOWED BY SMELL OF OIL BURNING IN CABIN. DESCENDED ACFT AND DIVERTED FROM FLIGHT PLAN. LANDED, INSP FOUND DEFECTIVE AIR CYCLE UNIT. OPERATION CONTINUED IAW MEL DEFERRAL OF AIR CYCLE UNIT. AIRCRAFT RELOCATED TO SERVICE CENTER. REPLACEMENT OF AIR CYCLE UNIT IAW CITATION 560 MM AND OPERATIONAL TEST PERFORMED. ACFT RETURNED TO SERVICE. (X)