The temperature goes up when the truck is parked?

Hi,

If the truck doesn't overheat if you are driving at highway speeds, suspect the fan clutch is failing to spin the fan fast enough to cool it while it is parked.

The fan clutch has a thermostatic bimetallic spring in the front that reacts to temperature change. Only when sufficient heat is present will the viscous fan drive engage. This is when the air flowing through the radiator core causes a reaction to the bimetallic coil. It then increases the fan speed to provide the necessary additional engine cooling.

Note that as the under-hood temperature gets higher, the fan will get louder. Actually, if it is fully engaged, oftentimes they sound like a jet engine and speed up with engine speed. If you are not hearing that, this is what I suspect is the problem.

If you look below, I attached the directions for replacing one. You will need a few simple tools specifically designed for the procedure, but most parts stores, such as AutoZone will lend you what is needed.

Take a look through the directions and let me know if you are comfortable performing the job or if you have other questions.

Take care,

Joe

See pics below.