Can 1999 Pontiac Montana run if the water thermostat is removed?
Yes the engine will run but not like it should. The thermostat is required on modern engines to get the engine to the proper operating temperature and keep it there. This will give you the very best mileage and performance. The optimum running temperature for most cars is 195 degrees Fahrenheit. without a thermostat the engine will take a long time to reach that temperature all the while wasting fuel. Without a thermostat the engine may run at a cooler temperature which is not a good thing contrary to what you might think. Anyone that tells you that your car doesn’t need a thermostat has no clue as to what’s going on with today’s cars! Microprocessors and sensors depend on a certain set of parameters from the manufacturer. Included in this mix is the engine temperature. Remove the thermostat, and you throw the computer system into a tizzy! Install the correct thermostat for your vehicle and leave it in.