Cooling system 2014 Silverado 1500, 5.3L

[smurray]

2014 Chevy 1500, replace thermostat, and Coolant temperature sensor. Started vehicle, temp cage reads 200, fans don't come on and hoses do not get hot, when driven temp does not rise higher than 204

[carriedi]

are you saying that the gauge reads 200 before the engine gets warmed up? Like, when you key on engine off, on a cold engine? If that is the case you should use a scanner to see what the computer shows as a temperature reading in degrees. See if the gauge matches the computer reading. Also, if the engine has been sitting for over 8 hours, or overnight, check the engine temp. and the intake air temp are close to the same reading. (within 16 degrees)

If you get a 200 degree reading from a warmed engine, that would be okay. Running at 204 would still be okay. The thermostat is set for around 200 degrees before it opens.

Do the fans come on when you turn on the AC? Does the heater have air out of the vent when you put the heater on hot and your gauge says 200? Heater fan on low, you should have 160 degrees out of the vent or hotter.

Do you have an infrared temp gun you can measure the temp on the thermostat housing?

Do you think your engine is running cold or do you think your engine is running hot but the gauge is wrong and the fans aren't cooling the engine?