What was found
SMOKE OR FUMES IN CABIN, SOURCE UNKNOWN. SMELLED FUMES/ODOR DURING DESCENT BELOW 18000 THRUST LEVER IDLE CREW DEBRIEF REVEALS, ODOR MORE OILY AND SMOKEY. ONLY DURING INITIAL DECENT. PERFORMED SMOKE ODOR IN FLT DECK/CABIN CHECK PER AMM 05-51-26. NO DEFECTS. OPERATED ENGINES AT PART POWER 10 MINUTES BLEED/PACKS OFF 10 MINUTED BLEED PACKS ON. SLIGHT OILY SMELL DURING FIRST 7 SECONDS OF ENGINE RUN. NONE NOTED DURING FOLLING 20 MINUTES OF ENGINE RUN. NO FURTHER DEFECTS NOTED. OK FOR SERVICE.