A malfunctioning thermostat can cause a motor to overheat quickly or to keep the optimum temperature for a long time. This is a very important device of the car, which regulates the circulation of fluid in the cooling system. It is designed to provide rapid heating of the cold motor and at the same time to prevent the engine from overheating, maintaining its normal functioning.

Content

• 1 Features of the thermostat
• 2 Device breakdown
• 3 Check the thermostat

Features of the thermostat

The temperature sensor is involved in the full cycle of engine cooling. The thermostat regulates the direction of movement of the antifreeze within the system. When the engine is started, the device is in the closed position and thus prevents liquid from entering the radiator, where it cools down. At this time, the antifreeze is in motion along a small circle of the system and cools the motor. The optimum mode of operation of the engine is achieved in the case when the liquid is heated to 90 ° C. At this point, the antifreeze should begin to divert the heat, because the engine will overheat. The thermostat reacts to a change in temperature and opens the valve of the cooling system's large circle, through which the antifreeze passes through the radiator, cools down and again goes to the engine for a new portion of heat.

The device and principle of operation of the thermostat

Device breakdown

It happens that such a debugged system fails and stops working. It is at this point that motorists are wondering how to check the thermostat. First you need to understand the causes of the malfunction, since further action depends on it.

Possible damage:

• Valve jammed closed. In this situation, the sensor itself works and constantly tries to open the valve, however, it does not work. The fluid will move through a small circle of the system, thus continuing to inject heat. The engine overheating indicator should immediately light up on the dashboard;
• The valve is initially loose. In this case, the antifreeze immediately begins its movement in a large circle of the system. What could be the consequences? Getting into the radiator, the liquid cools and is not able to gain the optimum temperature of 90 degrees, because the engine simply does not heat up to this value. The operation of the thermostat will not be felt, and the motor will be constantly cooled. Incorrect operation is particularly acute in the cold season, when the engine becomes simply impossible to warm up to operating temperature.

On the left, the faulty thermostat, which is stuck in the open position, on the right - serviceable

That is why it is very important to understand how the thermostat is checked for operability. A badly heated engine consumes significantly more fuel, which burns worse and pollutes the environment.

See also: Is it possible to interfere with antifreeze antifreeze

Check the thermostat

There are several effective ways to verify the thermostat's performance, which will help ensure that system malfunctions are related to a malfunction of the device. The thermostat is most often located in a special space between the radiator and the engine. Performing his test, you must be very careful, because you can burn yourself badly about the hot components of the device. All methods for diagnosing the functioning of the device are based on the principles of its operation. The thermostat circulates antifreeze through a large or small circle of the cooling system by opening or closing the pipeline valve.

So, methods for testing thermostat operability:

1. The engine should be allowed to work for 2-3 minutes, and then gently touch the hose connecting the radiator and the thermostat with your hand. A cold hose indicates that the device is working. If it is warm, then the valve is not tightly closed. In such a situation, the engine will take a very long time working temperature, which would entail excessive fuel consumption. After that, it is worthwhile to let the motor reach an operating temperature ranging from 85 to 90 degrees. Then again, you need to touch the pipe. He has to be hot. A cold hose indicates that the valve is jammed in the closed state. Under these conditions, the motor will overheat, because the coolant will not be able to perform movement in a large circle.
2. We start the car and wait until the engine picks up the optimum temperature. Next, you need to touch the top hose, which leads to the radiator, and then feel the lower pipe coming from the radiator. The thermostat does not work properly if the lower hose is cold and the upper hose is hot, because in this case it does not create conditions for the normal circulation of antifreeze over a large cycle.
3. This method of testing can be applied at home.

   

   The most interesting way to check, the first stage - immersion

   

   The second stage - we heat the tank and monitor the condition of the thermostat - opened, so it’s working

   Before starting the diagnosis, it is necessary to allow the motor to cool down well and then completely drain the coolant. Next, remove the thermostat, put it in a suitable container and cover it with water. Before this, the water must be heated to a boil. The fault will be visible visually. If the valve of the device is open, it means that it is in good order, and if not, then it should be replaced. Inside the cylinder, located in the thermostat, is artificial wax that melts when it reaches 82 degrees. The wax expands and pushes the pin, thereby opening the valve. When the wax cools, the pin is again in its initial position.

See also: How much to change the antifreeze

Here is a simple thermostat check. I hope these tips were useful to you and will definitely help in case of malfunctions in the cooling system. Best regards and do not break!