Truck overheating

Hi Kyle,

It is important to know what the engine temp is actually getting to so it is easiest to use an infrared temp meter. Also, before you condemn the coolant and thermostat you need to make sure the fans are coming on to lower the coolant temperature. If they are not, that is your issue.

As for the temperature raising when you shut the vehicle off, this is normal. The coolant stops moving when you shut the engine off because the pump stops turning so the coolant gets hotter and the temp sensor picks this up.

As for the upper hose being hot and the lower being cold, this does not sound right depending on what you mean by cold. Use your temperature gauge and see what the temperature difference is. The lower hose is supposed to be colder because this is the coolant that going into the engine to keep it at proper temperature but when you say it is cold, that make me think there is a blockage in the radiator.

Let's start with verifying the operation of the cooling fan, then take your temperature readings on the upper hose, lower hose, various places on the engine block. It very well could be the coolant and thermostat but you need to verify these first or you just wasted time and money because it won't fix the issue.

https://www.2carpros.com/articles/fan-clutch-symptoms

https://www.2carpros.com/articles/how-a-clutch-fan-works

https://www.2carpros.com/articles/fan-clutch-removal

https://www.2carpros.com/articles/how-to-use-an-infrared-temperature-meter