Car thermostat how does it work

If you have read How Thermometers Work and done the experiment with the bottle and the straw, you have seen the same process in action. The wax happens to expand a good bit more because it is changing from a solid to a liquid in addition to expanding from the heat.

This same technique is used in automatic openers for greenhouse vents and skylights. See this page for an example. In these devices, the wax melts at a lower temperature. Sign up for our Newsletter!

Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe. Under the Hood. As coolant flows through the engine, it picks up excess heat. Once it leaves the engine, it goes to the radiator, where that excess heat is removed. It then makes a few more stops along its way through the cooling system and ends up back in the engine.

When the coolant in the engine gets too hot, this valve opens, letting it pass to the radiator where it will cool down. If it is not heated, the thermostat stays closed, allowing the coolant to continue circulating inside the block. How does the thermostat know when to open or close?

It features a unique type of wax that acts as an expanding agent. When the heat reaches a specific temperature, the agent expands, which opens the valve. Let us now look at a few of the most common signs that suggest your thermostat needs attention. This is precisely how it works for your car too. If the thermostat is not functioning correctly, the engine has no way to cool itself down.

One of the more obvious signs that something inside your cooling system is malfunctioning is a drop in fuel economy. As one of the primary devices in charge of controlling the temp inside the engine, if the thermostat is not working, the gauge will end up outside the range it should be. If the thermostat is stuck in the open position, the coolant will continually flow. This can hinder the engine from reaching its optimal operating temp, reducing things like engine power and fuel economy.

This happens when the thermostat gets stuck closed, not allowing the hot coolant to cool down in the radiator. When the engine is shut off the process reverses to start all over again when the engine is restarted. Most often when thermostats are failing one of two things has happened: the thermostat is either stuck in the open position or has stuck closed.

Thermostat replacements are a fairly inexpensive repair when compared to the cost of replacing an engine, due to damage caused by excessive heat or repeated overheating. Here are three of the most common symptoms your vehicle may experience when a thermostat replacement is necessary:. Though small, the thermostat is mighty. Ensuring the thermostat is working properly is vital to make sure your engine maintains the proper temperature to function.

Neglecting to address the symptoms that indicate your thermostat is under duress, could result in permanent damage to the engine which will result in costly and extensive repairs. Enter your email address and we'll email you a digital version of this coupon that you can present on your mobile device at your Sun Devil Auto Shop.

Skip to content. Find a Location Locations. Make An Appointment Appointments. Common Problems With Car Thermostats Most often when thermostats are failing one of two things has happened: the thermostat is either stuck in the open position or has stuck closed.

Unfortunately, no.