What was found
DESCENDING THROUGH 4000 CA AND FO BOTH BEGAN TO SMELL A DIRTY SOCK FUME. THE SMELL BECAME STRONGER AND SLIGHTLY MORE ACRID DURING THE REMAINDER OF THE DESCENT. FWD FA'SQUIRED BUT DID NOT SMELL THE ODOR. UPON LANDING THE COCKPIT WINDOWS WERE OPENED AND THE ODOR DISAPATED. FOUND OIL PUDDLING IN EXHAUST SLEEVE AREA AFT. ENG SHUTDOWN PER B737 AMM 71-71-00-200-801. F00 PAPA 9. OIL CONSUMPTION NORMAL. OIL PUDDLING IS ACCEPTABLE. PER MCC PERFORMED STEPS TO REMOVE OIL DECONTAMINATION FROM APU. LT ENG AND RT ENG. PNEUMATIC DUCT BURN PER B737 AMM 21-00-01-100-501 SUBTASK 860-005/860-009/860-016. RUN PACKS. NO ODOR NOTED. (LOG 8603966 - AIRCRAFT WAS GROUNDED).