What was found
AFTER TAKEOFF RECEIVED NR 1 & NR 2 ENGINE BLEED CLASS MESSAGES. BOTH BLEED VALVES CLOSED & TEMP AT 320 C, CYCLED SWITCHES WITH NO SUCCESS. TURNED APU BLEED ON & BOTH ENG BLEEDS RETURNED TO NORMAL. RETURNED BOTH ENG BLEEDS TO SERVICE & 2 MIN LATER BOTH ENG BLEEDS FAULTED AGAIN. CYCLED BLEED CIRCUIT BREAKERS PER MX CONTROL & CAPT EMERGENCY AUTHORITY & BOTH BLEEDS RETURNED TO NORMAL. AFTER TURNBACK OBSERVED HOT ODOR, TURNED BOTH BLEEDS OFF, LANDED WITHOUT EVENT. MX PERFORMED A FUNCTIONAL CHECK OF FAN AIR VALVES, CHECK WAS GOOD. REMOVED & REPLACED NR 1 & NR 2 ENG TEMP CONTROL THERMOSTATS. OPS AND LEAK CHECKS GOOD. BLEED MONITORING COMPUTERS 1 & 2 BOTH CHECKED GOOD ON CENTRALIZED FAULT DISPLAY SYS.