As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER 2ND POST FLIGHT OF THE DAY DISCOVERED OIL LEAKING FROM APU EXHAUST FWD ALONG BOTTOM OF FUSELAGE. APU WAS STARTED ON GROUND AND COCKPIT FILLED WITH SMOKE FROM WEMACS. CABIN ALSO FILLED WITH SMOKE, DID NOT NOTICE FROM WHERE. APU WAS SHUTDOWN. ENGINES WERE STARTED AND BLEEDS WERE SELECTED LT AND RT TO ISOLATE POSSIBLE SOURCE. NO SMOKE WAS NOTICED. SMOKE SOURCE WAS ISOLATED TO APU OPERATION.