What was found
DURING CLIMBOUT, NR 2 FUEL TEMP ROSE TO 75 DEG C FOLLOWED E/A CHECKLIST. TEMP DID NOT STAY IN NORMAL RANGE WITHOUT AUX PUMP ON.AND LEVEL FLIGHT. DURING CRUISE TEMP ROSE TO 73 DEG C WITH AUX PUMP ON. THEN SETTLED AT 68 DEG C WITH AUX PU820100-3-007 OFF DURING DESCENT TEMP ROSE TO 75 DEG C WITH AUX PU820100-3-007 ON AND REMAINED AT THAT TEMP TILL AT GATE. R & R FUEL HEATER THERMAL ACTUATOR VALVE REMOVED IAW AMM TASK 73-11-05-000-801. INSTALLED IAW 73-11-05-400-801 C/W HS 73-0039. REMOVED AND INSTALLED FUEL HEATER OIL PRESSURE RELIEF VALVE IAW AMM TASK 73-11-02-000-801 INSTALLED IAW 73-11-02-400-801. PERFORMED LEAK CHECK IAW TASK 73-00-00-790-801 NO LEAKS NOTED OIL AND FUEL TEMPS NORMAL. RETURNED TO SERVICE.