thermostat on c13?

Seems low but mine runs at 175F almost all the time... put a load on it and see what it does.

 

You want to buy an Infrared temp gun, and with the engine cold, be sure the rad cap holds preasure, then run the truck, at about 1500 RPM, cover the rad with plastic, monitor the top rad pipe it should stay cold until the thermostats open. If the top pipe warms up as the engine does then either the thermostat is partially open or the seal is leaking. Take it to thermostat opening tempature. They are not made to run that cold.

 

C13 twin turbo have a waterjacket intercooler, if the deverter valve is stuck open, the engine could also run cold.

 

my c13 goes normal with 170-180*,when iam loaded and in the hills goes to 220*,plenty of times goes to 150 when iam speeding down,never troubles with this engine now 570k i buy the truck with 470k,100000 MILES NO TROUBLES iam happy i change the oil every 20000miles mobile delvac elite with org catfilters,no oil or water losing is for my a good engine

 

I'm assuming you're talking about the pre-cooler after the turbos? Isnt that to help cool the air before it enters the aftercooler? Or is it to help cool the coolant?

 

It is to help cool the air, but have seen it overcool the engine when engine is under small load factor with the deverter valve stuck open..