What was found
CABIN ODOR: ON ROTATION NOTICED A STRONG SMELL OF BURNING OIL. SMELL DISSIPATED AFTER 1-2 MINUTES. CORRECTIVE ACTION; REMOVED OIL STREAKING FROM AIRCRAFT TAIL, AND LEAK CHECKED APU. NO LEAKS NOTED, SUSPECT APU OIL WAS OVERSERVICED. COMPLETED BORESCOPE OF THE APU COMPRESSOR INLET AREA AND FORWARDED IMAGES TO MCC AND HONEYWELL. COMPLETED ENVIRONMENTAL CONTROL SYSTEM BLEED AND TRIM BLEED DUCT BURN PROCEDURE AND DETECTED NO EVIDENCE OF BURNING OIL SMELL REF TC-68A-21-181006MR3 .