We replaced the injection pump on our shop's 2010 Silverado and got everything put back together with 0 extra parts or bolts (big win on an engine we know very little about), cranked her a couple times for about 30 seconds each after we primed the fuel head to get the fluids back where they're supposed to be, 3rd hit she fires right up and has a slight vibration at idle but not bad enough to suspect a misfire. However, we noticed she's dropping coolant, there is a decent size puddle underneath but the puke tank reservoir hasn't gone down at all and she's running a bit hot (210° for 5 minutes of idling). I was able to trace where the coolant seems to be coming from and it's slowly flowing from under the passenger side alternator (running duals, I'm not sure which is the primary) in the general direction of where the coolant crossover pipe bolts to the passenger side head. Then there is the high temp issue, could the thermostat be sticking all of the sudden? Are both thermostats in the crossover pipe really needed? We are in Guam and the ambient air temp rarely drops below 80°.

 

my guess would be air in the coolant. open the bleeder bolt on the thermostat housing and let the air out while the engine is idling