What was found
DURING DEPARTURE CLIMBOUT WITH APU OFF CREW DETECTED AN EXHAUST/OILY SMELL WITH NO SMOKE INDICATED IN THE AIRCRAFT. ON POST FLIGHT WITH APU RUNNING, ODOR PERSISTS. ATTEMPTED TO DUPLICATE ODOR USING APU, LT ENG, & RT ENG. ODOR COULD NOT BE DUPLICATED. BORESCOPE OF THE APU INLET COMPRESSOR. NO FINDINGS. MCC HAS ELECTED TO REPLACE ACM MUFFLER & CONDENSER OUTLET DUCT. TECHS REMOVED SUSPECT ACM MUFFLER AND ACM CONDENSER OUTLET DUCT AND INSTALLED RECEIVED CUSTOMER PROVIDED K-BALL UNITS. PERFORMED LEAK CHECKS WITH NO LEAKS NOTED. TECHS ALSO VERIFIED NO ABNORMAL SMELLS IN THE COCKPIT OR CABIN. ALL WORK IS DONE WITH REFERENCE TO AMM 21-50-65 AND 21-50-77.