My car's engine is running hot. What could be wrong?

July 22, 2021

Is your car’s engine running at the right temperature to get the best fuel economy?

The thermostat is an essential part of your cooling system. Your vehicle thermostat performs a similar function to the thermostats in your home. At home, you set your thermostat to maintain a comfortable temperature range. When your home gets too hot, the air conditioning kicks on and when it gets too cool, the heater turns on.

Now your engine also has an optimal temperature range: warm enough to run efficiently and not so hot as to cause engine damage. Your vehicle’s thermostat is a critical valve between the engine and the radiator. When motorists first start a cold engine, the valve (thermostat) is closed, allowing the coolant surrounding the engine to warm up to the proper operating temperature. As the coolant gets hotter, the thermostat opens, allowing the heated coolant to flow through to the radiator to be cooled. The thermostat opens and closes to keep the engine within a certain temperature range.

Now thermostats are rated for a specific temperature depending on the engine – not a one size fits all applications. Thermostats are subject to normal wear. Proper operation depends on a special wax that expands as it heats up to open a spring-loaded valve. A worn thermostat could stick in the open position causing the engine to run too cool. This is inefficient and could curtail performance and your vehicles ability to achieve the best fuel economy as designed by the manufacture. If a thermostat sticks in the closed position, the engine can be subject to the dangerous results of overheating and possible severe engine damage.

There isn’t a specific routine for vehicle owners to maintain their thermostat, but maintaining the cooling system by changing the coolant/antifreeze on schedule will make sure the coolant has enough required corrosion inhibitors to protect the thermostat and other critical system components. Cooling system experts and the team at J’s Auto Service in recommend replacing your thermostat when you do a coolant flush or exchange. Also, thermostats usually wear out faster than your hoses, so if a worn hose replacement is required, it is a good practice is to replace the thermostat at the same time.

If your temperature warning light comes on, have a diagnostic examination of your cooling system right away. This could be a thermostat issue. The thermostat could also be the culprit for motorists who aren’t getting hot air when they turn on their heater.

The thermostat is a relatively inexpensive part that stands guard between you and catastrophic and pricey engine damage. Follow your auto manufacturer’s manual instructions, or let us review your service records concerning your last cooling system service

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