Just recently my '01 SuperCrew with 97,000 miles does not get as hot as it once did. The needle moves up about an 1/8 of inch on the gage and with the motor running for well over an hour I can barely feel any heat on the top radiator hose and I feel no resistance when I squeeze the hose. The air blowing from the heater inside is not hot at all as well.

The overflow tank is at the correct level.

Thanks,

Mike Mueller
Antioch, CA

 

Makes me think the thermostat is stuck open.

 

Second that. And while your replacing your T-stat, it would be a good idea to flush the system as well.

SL