What was found
SJM - FLT 203 - DURING FLIGHT FROM MIAMI TO BOGATA, NR 3 ENGINE START VALVE OPEN LIGHT CAME ON. SHUT DOWN NR 3 ENGINE AS PRECAUTIONARY AND COMPLETED AIR TURN BACK TO MIAMI, AIRCRAFT LANDED AT 655,000 POUNDS. REPLACED NR 3 ENGINE START VALVE PRESSURE SWITCH, PN 215N4113. INDICATION CHECKED GOOD. ACCOMPLISHED OVERWEIGHT LANDING INSPECTION PER BOEING, MM CMT 5-51-39. NO DEFECTS NOTED.