What does a radiator thermostat do for cars? How does the thermostat function? Thermostat malfunction symptoms and checks …..
The radiator thermostat is a tiny piece measuring 2 inches in diameter that is located between the radiator’s radiator and engine. It controls the coolant flow and maintains a constant temperature. This keeps the engine from heating up.
The thermostat is installed at the outlet of the coolant water. It regulates the temperature of the water to a set point. To achieve maximum engine performance, the ideal coolant temperature should be between 80-120 °C (based on catalog value). To bring the engine up to the recommended temperature, the coolant temperature should not be lower than 80-120 degrees Celsius. Instead, the radiator should be turned off and the engine heated as quickly as possible. The radiator can only circulate coolant water when it is hotter. The thermostat regulates the temperature of the coolant by changing the volume of cooling water that circulates through the radiator.
Types of thermostats
There are three types, wax pallet mechanical controller, wax pallet electronics control and bellows. Today, the bellows style thermostat, which has a smaller opening force when the cooling system pressure increases, is more commonly used.
Bellow Type Thermostats
This type of thermostat is made up of a metal bellows attached to a mushroom-type gate and a protector for the bellows. The liquid evaporated at low temperatures was put inside the bellows, and the air in the bellows was then evacuated. The vacuum created by the bellows in the engine keeps the valve closed when it is cold. As the engine heats up, the steam from the liquid evaporates and creates pressure in the bellows. The pressure causes the valve to open by inflating the bellows.
Thermo-wax pellet (Box Type thermostats)
A small box is used to store a type of wax (wax) in thermostats that do not use liquid. This paste expands and liquefies under heat, pushing a stick upwards. The rod acts as a lever arm and turns the throttle shaft. The shaft is connected to a butterfly valve. The butterfly valve connected to the shaft opens when the substance shrinks due to cooling. It can be closed by pulling on the springs attached to the valve.
Termo-Vaks Palette – Electronically Controlled Thermostats
These thermostats are found in modern cars. It works the same way the thermo-wax type thermostat. A heating resistance is added to the thermostat. The thermostat is located inside the coolant distributor housing. The distribution station that distributes cooling water to both the small and large cooling circuits is called the distributor housing. The thermostat’s heating resistance is controlled by the electronic control unit. It is heated according to the performance of the engine. Water is then sent to the appropriate parts of the engine.
Structure of thermostats
A thermostat comprises a body and valve. There are two types of thermostat valves: the butterfly or mushroom type.
1. A liquid is contained within the bellows that quickly evaporates in the presence heat. This liquid expands rapidly in the presence of heat. The pressure created in the bellows causes the bellows to inflate and push the mushroom-type valve attached to it open (Bellows style).
2. Auxiliary fittings are used in thermostats that use wax to open the thermostat valve when coolant temperature rises (Box Type).
3. Auxiliary fittings are used in thermostats that use wax to open the thermostat valve when cooling water temperatures rise and the electronic controlled heating resistance heats up (Box Type).
What Does the Thermostat Do?
The thermostat will close when the engine is off, stopping coolant from flowing through. This continues until the engine is at its optimal operating temperature. The thermostat is kept open when the engine temperature rises beyond a set temperature. This allows coolant to flow. This temperature will vary depending upon the type of thermostat that is used. It can be 89 °C in some vehicles and 93 °C in others.
As temperature rises, mercury in the thermostat’s center expands. It pushes against the valve at the ends and allows water to pass. As the engine water begins to cool, the expansion slows down and the cover is shut off. This is an easy but effective way of controlling the engine’s temperature.
Thermostat Controls
Thermostats can only be opened at certain temperatures. Thermostats used in engines should start to open at a temperature between 60 °C – 64 °C and fully open at 77 °C. In today’s engines, the thermostats start to open at 80 °C and open completely at 110 °C. The operating conditions of an engine and the type or antifreeze used determine the thermostat selection.
The thermostat is controlled by a water container. The thermostat is suspended with string or wire to ensure it doesn’t touch the bottom. The vessel’s water is then heated. The thermometer inside the container regulates the water’s temperature. When the water is heated, if the thermostat opens 6 – 7°C before the temperature at which it should be opened, or if the valve does not open even though the temperature of the water exceeds the temperature at which the thermostat should be opened by approximately 6 – 9°C, the thermostat is defective and must be replaced.
What are the Signs and Symptoms of Thermostat Failure
Thermostats are vital components of the cooling system of motor vehicles. They have a limited working life. There are no signs of any malfunction. Extreme temperature changes can cause wear and warping to the thermostat valve and other parts. The thermostats stop working properly due to rust, dirt and other foreign substances in the waters. The thermostat can malfunction if it is exposed to too much heat. When they fail, thermostats will usually remain open. The vacuum within the bellows ensures that the valve stays closed. Since the vacuum in the bellows can be punctured, the atmosphere pressure will cause the bellows’ to burst and make sure that the valve is always open. The thermostat rarely causes the engine’s temperature to rise. The thermostat can fail, causing the engine to heat up to its normal operating temperature, especially in winter.
