alright im stumped my coolant temp on the gauge will not get passed 140 and every now and then the computer will throw a overcooling code. i have replaced the temp. sensor, new coolant,2 new thermostats and it did it before the other thermostat change. does the computer read off of the gauge temp or the temp sensor. because idk whats wrong

 

what year truck?

 

What engine and how many miles on it? I'm thinking you have 140,000 miles or more and your timing chain is stretched. It'll still run but won't ever really warm up. If you know what to listen for, you can hear timing chain slap under the water pump.

 

2001 360 v8

 

Only one sensor, and the PCM tells the cluster what to display.

What brand/type of thermostat are you installing? If you are using 'safety stats', don't. They suck. Get a good Stant thermostat, (NOT the 'safety' variety) and try again. Might not hurt to pick up an infra-red temp gun, and see what temp the thermostat housing is actually getting to. It's possible the sensor simply isn't grounding to the manifold good enough to work properly.

 

Clutch fan seized?

 

i purchased a WVE sensor
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Ever check your timing chain?

 

so i figured it out i covered the radiator with more than half with cardboard and the truck finally got up to operating temp so i am assuming the fan clutch is stuck full engaged

 

Yes, it can and does happen. Rotate it by hand to check its operation.