2002 ford ranger XL I'm having problems with it ok this sounds crazy but when i drive the truck for like 40mins non-stop for some reason your temperature gauge drops.after awhile it slowly goes back?

Answer 1

Atually, it doesn't sound crazy. It's a sticking thermostat. When the engine warms, the thermostat opens to allow the engine to cool, then it sticks open. The water pump keeps pushing hot coolant through the radiator, and the engine cools down more than you'd like. Eventually the thermostat starts to close a little and the engine starts to warm again. Replace the thermostat and your problem should go away. To add to this, I had the same problem with my ranger. I changed the thermostat and it helped for a while, then it went right back to what you describe. I asked another mechanic and he told me to flush out the heater core. The coolant circulates through it first, and if it is partially clogged, it will build up pressure before the collant can pass through. That's when your temp. guage goes up. When the pressure is great enough, the coolant will go through and send the temp back down. As a result the motor will run hot, also you will not get much heat from the heater. i blew mine out with an air compressor and it worked fine after that.