I have a 2000 Plymoth Grand Voyager with a 3.0 Liter engine. The temp guage on the dash says its running hot, but the mechanic said the engine and radiator is showing 200 degrees. we put a new thermostat and water pump in and that didn’t fix the problem. Now my a/c isn’t working right, I can hear a sqeeling belt, and my power is sluggish, as well as fuel usage has increased. what can be the issue here?.