The principle of the thermostat in the car: the scheme, device and recommendations

Every day we are faced with the need to adjust the water temperature. For such purposes, a mixer with a thermostat was invented. The principle of its operation is very simple. But today we will talk about how the thermostat works in a car. This is a very important detail that maintains the normal temperature range of the coolant. Water is not always used as the latter. Now this function is performed by a more technological antifreeze or antifreeze.

Mechanism arrangement

This is a very small detail that fits in the palm of your hand. It consists of a body, a stem, inlet, outlet nozzles, as well as a rubber chamber. As a working substance, a wax filler is used. Yes-yes - it is on wax that the principle of the VAZ thermostat and many other cars is based. Among other things, the design also has a return spring, O-ring, valve disc and guide. The diagram of this mechanism can be seen in the photo above.

Functions

The thermostat (the principle of its operation we will consider below) serves to regulate the temperature of the cooling liquid in the system. The element performs several tasks at once:

• Maintain the desired thermal conditions of the engine.
• Acceleration of warm-up of the power unit.

Thermostat operation principle

As we said earlier, it is based on a thermoelement - wax filler. It is he who controls the movement of the valve. In the device of the element there are no electronics - everything is controlled mechanically. So, what is the principle of the thermostat? When the engine is running, the valve element is in the closed state. Thus, the pump circulates the fluid only over a small circle, bypassing the main radiator. This ensures a quick warm-up of the engine. As soon as the temperature has reached the specified mark (it can be 70-85 degrees, depending on the model and type of auto), the substance begins to melt. Under the action of the spring, a valve opens. As a result, the antifreeze starts to go to the radiator, which provides cooling of the liquid.

After the car has stopped its work, the temperature of the antifreeze starts to fall. When it reaches a certain mark (below 70 degrees), the valve closes. Thus, the system will be prepared for a "cold" start, where the engine will provide rapid warm-up.

It is worth noting that the valve closes and opens the valve not immediately. The principle of the thermostat in the car is designed in such a way that the element can only be opened halfway. Usually this range is 70-80 degrees. In full, it will open only at temperatures over 95 degrees. In the same way, the valve closes smoothly.

About faults

Note that this mechanism is highly reliable and malfunctions associated with the thermostat are very rare. The first problem is a permanently open valve. In this case, the liquid will pass through the main radiator constantly, even with a cold start. The problem is fraught with prolonged warming up of the car, especially in the winter.

The second problem is a permanently closed thermostat. Unlike the first, this malfunction is clearly manifested in both winter and summer. Signs of breakage - too fast warm up of the motor and overheating. The arrow does not hold in the green zone and begins to swiftly leave the red scale, for 110 degrees. Overheating is a very dangerous phenomenon for the engine. Therefore, if the machine starts to boil, muffle the engine and in tow move to the repair site (or with long pauses go yourself by monitoring the pointer of the sensor on the instrument panel). The next problem is an early discovery. This phenomenon is also equated with a malfunction and occurs most often due to marriage. The motor not only warms up to operating temperatures for a long time, but also does not reach its "green" regime. So, the arrow on the panel does not grow above 70 degrees. A constant ride on a cold engine can provoke an increased fuel consumption.

Reason for breakdowns, methods of solution

In 99 percent of the cause of the malfunction is a thermocouple. In the first case, in the second case, the wax could be washed out due to a breakdown and depressurization of the chamber (or it dried up due to time). In the third, the manufacturer simply did not report the thermoelement in its entirety or installed a low-quality spring. But in any case, the only way to solve the problem is to purchase and install a new thermostat. The element is not collapsible and changes entirely. And its cost is not too great to take repair measures.

Recommendations for use

On domestic cars, there are often problems with maintaining the operating temperature of the engine. Moreover, this can occur even on a working thermostat. To solve this problem, experts recommend using different thermostats seasonally. For example, in winter, ride with the element at 85 degrees, and in the summer - at 75. So the car will warm up more quickly in the winter and not boil in the summer. Also you will not have problems with a cold stove. If you have a 5-hole old-style thermostat (this carburetor VAZ, including the "nine"), it should be replaced by a more efficient, 6-hole. The cost of this mechanism is 800 rubles. As practice has shown, with it the motor quickly heats up in a 20-degree frost, the furnace perfectly works.

How to check?

Since the operating principle of the thermostat ("Kalina" including) is the same, this instruction is suitable for all cars. Check the element can be in place without removing it. To do this, warm up the car to operating temperatures, muffle and feel the nozzles in the top and bottom of the radiator. Be careful - they can be hot (use gloves). If the needle has reached 80-90 degrees, and one of the nozzles (or both) is cold, then the element jammed and does not work. In more detail, determine the integrity of the element can be removed. To do this, it is placed in a container of water and brought to a boiling point. The principle of the thermostat is based on the melting of the wax, which opens the valve. This can be seen visually by placing the part in boiling water.

So, we have found out the operating principle of the thermostat and its main malfunctions.