What was found
PNEUMATIC DISTRIBUTION: DURING A LONGER FLIGHT, ONCE THE CABIN BECOMES COLD SOAKED, AND THE SUPPLY DUCT TEMPERATURE WARMS UP WE NOTICED A SLIGHT OIL BURNING ODOR COMING FROM THE VENTS. I CHECKED THE VENT SUPPLY TEMPERATURE AND IT WAS ONLY SHOWING ABOUT 140. //SIGNOFF// REMOVED DIRTY CONDENSER BAG (PN: 83237-12) AND INSTALLED A NEW CUSTOMER SUPPLIED CONDENSER BAG (PN:83237-12), REINSTALLED WATER SEPARATOR IN AIRCRAFT AND OPS CHECK GOOD REF CE-680 MM 21-21-03.