They can also make your car more comfortable

In recent weeks, this blog has focused on coolant/antifreeze, freeze plugs and radiator hoses – all integral parts of a car’s cooling system. There is another part of the cooling system that plays a vital role in its efficient operation that we have not discussed – the thermostat.

In your home, you have a thermostat on the wall that you can adjust to operate your furnace so the house stays at a desired temperature. The thermostat in the house is an apparatus that often leads to battles between husbands and wives. Some like it hotter, some like it cooler and never the twain shall meet.

Your car’s thermostat also adjusts the temperature. But, once it’s installed, there are no adjustments to make and nothing for a husband and wife to argue about.

A car’s thermostat operates a valve that opens and closes. Closed, it blocks the flow of cooled coolant out of the radiator and into the engine. Why would you want to stop the flow of coolant into the engine, especially considering all we’ve discussed the last few weeks about the importance of coolant in the smooth and reliable operation of your car’s engine?

Without a thermostat, a car’s coolant would flow always and unimpeded into the engine block and back into the radiator, constantly removing heat. But, engines are designed to operate best at optimal temperatures. When the thermostat closes the valve, the coolant is trapped inside the engine block until it reaches optimal operating temperature. Then, the thermostat opens.

When the cooling process causes the temperature of the coolant to reach a predetermined low point, based on the thermostat that is installed in the car, the thermostat shuts the valve again. In this way, it keeps the engine operating within a preferred range of temperatures.

By keeping the thermostat closed at lower temperatures, the thermostat also makes warmer coolant available to flow through the heater core. The heater core is like a small radiator that provides heat for the inside of the car’s cabin. In other words, it provides heat for you when you’re shivering inside the car waiting for the engine to heat up sufficiently.

Many thermostats open at 200-degrees Fahrenheit while others may open at 180 degrees. Some might say that the latter is more of a summer thermostat. The thermostat that doesn’t open until the coolant reaches 200 degrees is better for winter. Of course, it really comes down to the temperature where a car runs best.

A real problem with a thermostat occurs when the thermostat locks into place. Whether stuck open or closed, it’s a problem that will bring you to your auto repair shop or the side of the road. Over time, thermostats fail. You may want to consider replacing the thermostat after a few years rather than waiting for it to fail.