What was found
LIM-MIA - DURING CLIMB AT FL250, NR 4 NACELLE TEMP WENT OT 8.0 WITH A FIRE BELL AND LIGHT IN NR 4 FIRE SWITCH. WHEN NR 4 THRUST LEVER WAS RETARDED TO IDLE, THE FIRE LIGHT WENT OUT AND THE NACELLE TEMP RETURNED TO NORMAL 2.0. CLOSED NR 4 BLEED VALVE AND ADVANCED THROTTLE. NACELLE REMAINED NORMAL. REMOVED AND REPLACED PRESSURE RELIEF VALVE PER MM 36-11-03. LEAK CHECK OK. REMOVED AND REPLACED REGULATING VALVE, P/N 878806-1, PER MM 36-11-19. LEAK CHECK OK. (M)