I have a 94 Saturn 1.9L dohc. When it idles the gauge shows half way up but when I drive 65-70 mph on the freeway the gauge goes to C-cold. when I stop at a light the temp claims again. Any ideas????
Thermostat's probably stuck open. My car had the same problem.
Replace thermostat. Also, when car is at operating temp, pop the hood and feel the radiator and it's 2 hoses. Are they hot? Cold? If radiator and hoses are all not hot/warm then problem may be your water pump.
So you're saying that a bad water pump would make the car run cold. How exactly is that going to happen? Please explain in depth.