What was found
DURING NR 1 ENG RUN, "L IDG VALVE" MESSAGE APPEARED ON LOWER EICAS, MESSAGE WOULD ERASE, BUT RE-APPEAR ON NEXT ENG RUN. IDG AIR-OIL HEAT EXCHANGER VALVE OVERRIDE SWITCH WAS REPLACED. REMOVED AND PUT NEW COOLER IN PLACE. IDG AIR-OIL HEAT EXCHANGER VALVE OVERRIDE SWITCH WAS REPLACED. NEED TO REPLACE IDG AIR OIL HEAT EXCHANGER. CENTER MOUNT BOLTS NEED TO BE INSTALLED PRIOR TO MAKING CONNECTIONS. COMPLETED INSTALLATION OF AIR OIL HEAT EXCHANGER.