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How does a Car Thermostat work?

There are almost 30,000 spare parts in a car. 

Each part has a significance of it’s own.  

Thermostat is an important part of a car’s engine cooling system system

In this blog, you’ll read:

  • What is a car thermostat?
  • How does a car thermostat work
  • What are the two most common types of thermostat
  • Signs and symptoms of a faulty thermostat

Let’s dive in…

What Is A Car Thermostat?

A car is a complex machine that has various systems interconnected and interdependent. As the load on the engine increases, the temperature also increases. Hence, a system is put into place to regulate the temperature of the engine. A car thermostat is a component of this system.

The function of a car thermostat is to maintain the circulation of engine cooling from the radiator. It is also responsible for preventing the situation of overheating of the engine. The purpose of an engine cooling system is to maintain the temperature of the engine at an ideal condition. 

The ideal temperature of an engine is between 80 degrees Celsius to 92 degrees Celsius. At this temperature, the combustion process of the engine is required for it to run smoothly, and the fuel consumption is also efficient. The position of the thermostat is below the waterline that goes from the engine to the radiator. 

Car Thermostats are of two types – Thermostats without Bypass Valves and Thermostats with Bypass Valves.

Thermostat without Bypass Valves

New cars are uncommon to employ this kind of thermostat. It is often only seen in older vehicles. This thermostat, located on the radiator intake, is still without a backup line that would allow cooling water to flow in the event of a thermostat malfunction. When the car engine is cold, water will become trapped in the radiator and water jacket.

This kind of thermostat has the benefit of being reasonably priced. There are certain disadvantages, though. A thermostat without a bypass valve has no safety line in the case of a malfunction. Additionally, there are no water lines that can be used to cool down a hot car engine.

Thermostat with Bypass Valves

how does a car thermostat work

Contrary to the earlier form, thermostats with bypass valves are frequently found in modern automobiles. The thermostat for this type is located at the radiator outlet and includes a built-in bypass valve. In this type, the radiator cannot be heated by the water coolant, which instead travels from the water jacket to the thermostat and then the water pump before returning to the water jacket.

The benefit of using a thermostat with a bypass valve is that it has a safety line in case of breakage and can quickly reduce the heated engine temperature. The disadvantage is that it costs a considerable amount due to the complexity involved in making it

How Does a Car Thermostat Work?

Excess heat is absorbed by the coolant as it moves through the engine. It travels to the radiator after leaving the engine, where extra heat is dissipated. It then stops at a few more locations as it travels through the cooling system before returning to the engine. 

Between the engine and the radiator, the thermostat essentially functions as a valve.

This valve opens when the engine coolant becomes too hot, allowing it to transfer to the radiator, where it will cool down. The thermostat remains closed if it is not heated, enabling the coolant to circulate inside the block. It has a special wax that serves as an expanding agent. The agent expands when the heat reaches a particular degree, opening the valve.

The agent contracts when the heat decreases, putting the valve back in its normal closed position. An engine running on heated coolant won’t be able to cool down, which might lead to overheating.

What Are The Symptoms Of A Faulty Thermostat?

Readings of an Unusual Temperature

After a prolonged period of rest, you will typically see that the temperature indicator increases from the cold side to the midpoint, which is the ideal engine temperature. The coolant flow to the radiator will, however, be impacted by any thermostat problems. As a result, the temperature will continue to increase dangerously if the thermostat is stuck closed. The temperature will likely halt before reaching the midpoint if the thermostat is stuck open.

Changes in Cabin Temperature

Sudden variations in interior temperature are another typical sign of a broken temperature gauge. A malfunctioning thermostat that has to be replaced, can be identified, if you observe that the temperature inside your cabin abruptly decreases and then rises.

Leakage of Coolant

Coolant leakage is one of the most important indicators of a broken or failing thermostat. Typically, the thermostat component is stuck closed in the majority of failures. This signifies that the thermostat obstructs the coolant’s path to the radiator, causing an overflow of coolant to escape from the thermostat housing. A noticeable coolant leaking can be seen when this occurs. Even if the thermostat is working properly, have your car inspected.

Unusual Sounds Coming From The Engine Bay

You will hear odd noises coming from the engine bay as well as temperature variations if that weren’t enough. These noises may come from the engine, the radiator, or perhaps from both. These unusual noises, which resemble a knocking, boiling, or gurgling sound, can be an indication of a broken thermostat as well as several other issues.

Malfunction of Heater

Living somewhere colder increases the likelihood that your thermostat will be stuck open rather than closed, which will result in a heater malfunction as opposed to overheating. This implies that coolant will continue to flow to the engine even when it is not required. So be sure to check your heater as well if you live in a colder climate or are driving during the winter.

Even though thermostat issues are practically difficult to prevent, it would be wiser to repair a faulty one before it causes more trouble. And when you do that, be sure to select the highest-quality spares available.

Wrap Up: What is a Car Thermostat, How Does it Work and Signs of a Faulty Car Thermostat

So we’ve discussed the types of thermostat and the working of a thermostat.

To make sure that your thermostat doesn’t malfunction, please get your car services regularly and keep an eye on the symptoms of a bad thermostat.