What was found
FLT 2850, UIO-FLL. DESCENDING THRU 7,000 FEET IN CLEAR AIR EXPERIENCED MUSTY DIRTY SOCK SMELL IN FLIGHT DECK AND CABIN. SHUT CROSS BLEED AND TURNED PACK 1 OFF PER ODOR ISOLATION CHECK LIST. ODOR DIMINISHED IN ABOUT 90 SECONDS. LANDED PRIOR TO ANY FURTHER TROUBLESHOOTING SEE PREVIOUS WRITE UPS; DURING BOROSCPOE INSPECTION FOUND TRACES OF OIL ON NR 1 & 2 ENG. PER ENGINEERS REQUEST ACCOMPLISHED ENGINE WASH ON BOTH ENGINES RAN BOTH ENGINES. NO ODOR NOTED. AS PRECAUTIONARY ACCOMPLISHED ECS DECONTAMINATION. NO ODOR NOTED REF MM 72-00-00.