I only had this four days before the check engine light came on and the engine temp gauge at first started bouncing then settled in at just above cold regardless of how long the engine has been running. I've read about the engine temperature sensor and how to test it but I've also read about the"sending unit".are they the same thing? I'm Not at all a mechanic, just trying to have a little fun with an old truck but I don't want to start blindly changing parts.any answers or suggestions?

 

First things first, read the codes and post them so we know what is causing the check engine light. If you do not have a code reader you can go to the nearest autoparts store and they will let you use one.