What was found
DURING CLIMBOUT FROM PHL, EN ROUTE TO MCO, CREW REPORTED A SOUR ODOR HAD FILLED THE CABIN ATMOSPHERE CAUSING THE FORWARD LAVATORY SMOKE DETECTOR TO SOUND. SMELL DISSIPATED EN ROUTE BUT RETURNED ON FINAL APPROACH TO MCO. FLIGHT LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE FOUND THE RIGHT AIR CYCLE MACHINE OVERSERVICED. DRAINED OIL TO PROPER LEVEL. RAN ENGINES AND AIR CONDITIONING SYSTEMS. NO ODOR AT THIS TIME. AIRCRAFT OK FOR SERVICE.