1998 Ford F150 6 cyl Two Wheel Drive Manual 160000 miles
I am having a problem with my 1998 Ford F150. The heater will heat up and then get cool, then heat up again and cool again. It tends to heat better at a higher speed. Thermostat? If that is it, where is it located on the engine?
Sounds to me like you are low on coolant. With engine cool, open radiator cap and check level, if ok then replace thermostat. Follow the upper radiator hose to the engine and that is where your thermostat is located. Hope this helps