The engines are almost identical on all machines. A hybrid system is used on modern cars. Yes, exactly this, because not only liquid, but also air participates in cooling. It blows the radiator cells. As a result, cooling is much more efficient. It is no secret that at low speed, fluid circulation does not save - you have to additionally install a fan on the radiator.

Radiator fan

Let's talk about domestic cars, for example, about "Lada". To ensure better heat transfer, the engine cooling system (Kalina), the circuit of which has a standard configuration, contains a fan. Its main function is to blow air over the radiator cells when the liquid reaches a critical temperature. The work is controlled by a sensor. On domestic cars, it is installed at the bottom of the radiator. In other words, there is a liquid there that has released heat into the atmosphere. And it should have a temperature of 85-90 degrees at this point of the contour. If this value is exceeded, additional cooling must be carried out, otherwise boiling water will enter the engine jacket. Consequently, the motor will operate at critical temperatures.

Cooling radiator

It serves to transfer heat to the atmosphere. The liquid passes through the honeycomb, which has narrow channels. All of these cells are connected by thin plates that improve heat dissipation. When moving at high speed, air passes between the cells and contributes to the rapid achievement of the result. This element contains any diagram of the engine cooling system. Volkswagen, for example, is no exception.

Above, we considered a fan that is mounted on a radiator. It blows air when the critical temperature is reached. To improve the efficiency of the element, it is necessary to keep the radiator clean. Its honeycombs are clogged with debris, heat transfer deteriorates. Air does not pass well through the cells; heat is not released. As a result, the engine temperature rises, its operation is disrupted.

System thermostat

This is nothing more than a valve. It reacts to changes in temperature in the cooling circuit. More about them will be discussed below. The scheme of the UAZ engine cooling system is based on the use of a high-quality thermostat, which is made of a bimetallic plate. This plate deforms under the influence of temperature. It can be compared to a circuit breaker used in the power supply of homes and businesses. The only difference is that it is not the switch contacts that are controlled, but the valve that supplies hot liquid to the circuits. The design also has a return spring. When the bimetallic plate cools down, it returns to its original position. And the spring helps her to return.

Sensors used in cooling

Only two sensors are involved in the work. One is installed on the radiator, and the second is in the jacket of the engine block. Let's go back to domestic cars and remember the Volga. The cooling system circuit (405) of the engine also has two sensors. Moreover, the one on the radiator has a simpler design. It is also based on a bimetallic element that deforms when the temperature rises. This sensor turns on the electric fan.

On cars of the classic VAZ series, a direct fan drive was previously used. The impeller was installed directly on the pump axis. The fan rotated constantly, regardless of the temperature in the system. The second sensor, installed in the engine jacket, serves one purpose - transmitting a signal to the temperature indicator in the cabin.

Liquid pump

Let's go back to the Volga again. The cooling system, the circuit of which contains a circulating liquid pump, cannot simply function without it. If you do not give the fluid movement, then it will not be able to move along the contours. Consequently, stagnation will appear, the antifreeze will begin to boil, and the motor may jam.

The design of a liquid pump is very simple - an aluminum housing, rotor, drive pulley on one side, and a plastic impeller on the other. Installation is carried out either inside the engine block or outside. In the first case, the drive is carried out, as a rule, from the timing belt. For example, on VAZ cars, starting from model 2108. In the second case, the drive is carried out from a pulley

Stove outline

Some cars made several decades ago were equipped with engines with air cooled... There is only one inconvenience in this case: it was necessary to use a gasoline stove, which "ate" a lot of fuel. But if liquid circuits of engine cooling systems are used, you can take hot antifreeze, which is supplied to the radiator. Thanks to the stove fan, hot air is supplied to the passenger compartment.

In all cars, the heater radiator is mounted under the dashboard. First, an electric fan is installed, then a radiator is installed on it, and air ducts are suitable from above. They are needed to distribute hot air throughout the passenger compartment. In new cars, its distribution is controlled using microprocessor systems and stepper motors... They open or close the flaps depending on the temperature in the passenger compartment.

Expansion tank

Everyone knows that any liquid expands when heated - increases in volume. Therefore, it is necessary that she go somewhere. But on the other hand, when the liquid cools down, its volume decreases, therefore, it must be added to the system again. It is impossible to do this manually, but with the help of an expansion tank, this procedure can be automated.

Most modern cars hermetic engine cooling systems are used. For these purposes, there is a plug with two valves on the expansion tank: one for the inlet, the second for the outlet. This makes it possible to maintain a pressure in the system close to one atmosphere. With a decrease in its indicator, air is sucked in, with an increase - discharge.

Cooling system pipes

1 - Cork expansion tank. 2 - Expansion tank. 3 - Radiator supply hose. 4 - The hose from the radiator to the expansion tank. 5 - Radiator outlet hose. 6 - Left radiator reservoir. 7 - Aluminum radiator tubes. 8 - Sensor for turning on the electric fan. 9 - Right radiator reservoir. 10 - Drain plug. 11 - Radiator core. 12 - Electric fan casing. 13 - The impeller of the electric fan. 14 - Electric motor. 15 - Pump toothed pulley. 16 - Pump impeller. 17 - Toothed belt drive camshaft. 18 - Heater radiator outlet pipe. 19 - Pump inlet pipe. 20 - Hose for fluid supply to launcher carburetor. 21 - Carburetor heating block. 22 - Outlet pipe. 23 - Heater inlet pipe. 24 - Hose for removing fluid from the carburetor heating unit. 25 - Thermostat. 26 - Hose from expansion tank to thermostat.

Why you need an engine cooling system can already be guessed from the name - when working, the engine heats up and cools through the radiator. This is in brief. In fact, the task of the engine cooling system is to maintain its temperature within a certain range (85-100 degrees), called the operating temperature. At operating temperature, the motor runs as efficiently and safely as possible.

Large and small circle of the engine cooling system

After starting, the engine should reach operating temperature as quickly as possible. For this, it is divided into two parts - a small circle and a large circle of circulation. In a small circle, the coolant circulates as close as possible to the cylinders and, accordingly, heats up as quickly as possible. As soon as it warms up to the highest operating temperature, the valve opens and the liquid goes to a large circle, where it prevents the engine from overheating. The task of the small circle is to maintain the operating temperature, and the large circle is to remove excess heat.

Stove as part of the engine cooling system

It's nice when the interior warms up quickly, but this happens because this is part of a small circle of circulation. Through the hoses, the liquid goes to the stove radiator and returns back. What does it mean? In order for the stove to start blowing warm air faster, it must be turned on when the engine warms up.

Cooling pump and thermostat

So, we found out that the engine does not overheat due to the coolant circulation. But what makes the fluid move? The answer is. This is a special pump that is driven by a motor through a belt, but there are pumps with an electric motor. The main pump malfunctions associated with leakage through drain hole and bearing wear (accompanied by a squeak). There are also pumps with a plastic impeller, which is corroded by low-quality antifreeze.

This is the same valve that opens when the coolant heats up and lets it through a large circle... Consists of a cylinder with a substance that expands when heated; having reached a certain temperature, it squeezes out the stem and opens the valve. After cooling down, the stem retracts and the valve closes.

Radiator and coolant expansion tank

It is part of a large circle and is installed in front of the vehicle. A liquid circulates in it, which is cooled by oncoming air and a fan.

The fan works for suction so as not to impede the oncoming air flow.

The radiator cap maintains pressure in the cooling system. It has a valve that opens when the pressure exceeds the operating pressure and releases excess fluid through the hose into the expansion tank.

Today from our regular column “ How it works»You will learn the device and how it works engine cooling system, what is the thermostat for and radiator, as well as why it was not widely adopted air system cooling.

Cooling system engine internal combustion carries out heat removal from engine parts and transfer it to the environment. In addition to the main function, the system performs a number of minor ones: oil cooling in the lubrication system; heating air in the heating and air conditioning system; exhaust gas cooling, etc.

During the combustion of the working mixture, the temperature in the cylinder can reach 2500 ° C, while working temperature The internal combustion engine is 80-90 ° C. It is to maintain the optimal temperature regime that there is a cooling system, which can be of the following types, depending on the coolant: liquid, air and combined ... It should be noted that the liquid system in its pure form is practically not used anymore, since it is not able to maintain work for a long time modern engines in optimal thermal conditions.

Combined engine cooling system:

In a combined cooling system, the coolant is often water is used, since it has a high specific heat capacity, availability and harmlessness to the body. However, water has a number of significant disadvantages: the formation of scale and freezing at low temperatures... IN winter time years, it is necessary to fill the cooling system with low-freezing liquids - antifreezes ( aqueous solutions ethylene glycol, a mixture of water with alcohol or glycerin, with additives of hydrocarbons, etc.).

The cooling system under consideration consists of: a liquid pump, a radiator, a thermostat, an expansion tank, a cooling jacket for cylinders and heads, a fan, a temperature sensor and supply hoses.

It should be stipulated that the cooling of the engine is forced, which means that an overpressure (up to 100 kPa) is maintained in it, as a result of which the boiling point of the coolant rises to 120 ° C.

When starting a cold engine, it gradually heats up. At first, the coolant, under the action of a liquid pump, circulates in a small circle, that is, in the cavities between the cylinder walls and the engine walls (cooling jacket), without getting into the radiator. This limitation is necessary for the rapid introduction of the engine into an effective thermal regime. When the engine temperature exceeds optimal values, the coolant begins to circulate through the radiator, where it is actively cooled (called a large circle of circulation).

Device and principle of operation:

The coolant "running" through the radiator tubes is cooled when moving with the oncoming air flow.

FAN enhancesair flow through the radiator core. The fan hub is attached to the fluid pump shaft. They are together driven by a pulley crankshaft belts. The fan is enclosed in a casing mounted on the radiator frame, which increases the air flow rate through the radiator. Most often, four- and six-blade fans are used.

Air cooling system:

In an air cooling system, heat is removed from the walls of the combustion chambers and engine cylinders forcibly by an air flow generated by a powerful fan. This cooling system is the simplest, since it does not require complex parts and control systems. The intensity of air cooling of motors depends significantly on the organization of the air flow direction and the location of the fan.

IN inline engines fans are located in front, side or combined with a flywheel, and in V-shaped - usually in the camber between the cylinders. Depending on the location of the fan, the cylinders are cooled by air, which is forced or sucked through the cooling system.

The optimal temperature regime for an air-cooled engine is considered to be one at which the temperature of the oil in the engine lubrication system is 70 ... 110 ° C at all engine operating modes. This is possible under the condition that up to 35% of the heat released during the combustion of fuel in the engine cylinders is dissipated with the cooling air into the environment.

The air cooling system reduces the engine warm-up time, provides a stable heat removal from the walls of the combustion chambers and engine cylinders, is more reliable and convenient in operation, easy to maintain, more efficient when the engine is rear-mounted, engine overcooling is unlikely... However, the air cooling system increases dimensions engine, creates increased noise when the engine is running, it is more difficult to manufacture and requires the use of better quality fuels and lubricants. Heat capacity of air is small, which does not allow evenly discharging from the engine a large number of heat and, accordingly, create compact powerful power plants.

Normal functioning power plant car is possible only at a certain temperature. For most cars, the optimal temperature range is 80-90 degrees. C. At a lower rate, mixture formation in the cylinders worsens, and heat leads to expansion of the metal, which can cause jamming of the components.

General device cooling systems

To keep the temperature of the power plant in the optimal range, a cooling system is included in the design of the motor. It is thanks to it that heat is removed from the most heated elements - the cylinders.

Types of cooling systems

In total, internal combustion engines use two types of cooling - air and liquid.

Air cooling system, its design, disadvantages

Engine air cooling system

Due to a number of shortcomings, road transport the air system is not widespread, although structurally it is much simpler than the liquid one. Its main element is the cooling fins on the cylinders.

The heat released from the cylinders was distributed to these fins, and the air flow passing through them carried it out. To create a flow, the system design could additionally include a turbine - a special impeller driven by a crankshaft and a sleeve with which the generated air flow was directed to the cylinders. This is the whole structure of the air system.

The air system is practically not used in road transport because:

• it is impossible to adjust the temperature regime (in winter the motor did not reach the required temperature, and in summer it overheated very quickly);
• to ensure an even distribution of the air flow, each cylinder stood separately;
• when parked with the engine running, even with a turbine, the air flow is very weak, which leads to rapid overheating;
• it is impossible to arrange interior heating.

Due to these shortcomings, the air system is not used on cars, although there were still isolated cases - ZAZ-968 "Zaporozhets" had just such a cooling system. But it is widely used in motor vehicles and equipment equipped with 2-stroke motors (chainsaws, brushcutters, walk-behind tractors, etc.).

Video: Engine cooling system. Device and principle of operation

Device, design, principle of operation

Liquid cooling system

The advantage of a liquid cooling system is precisely the ability to maintain the temperature in a given range, therefore it is better than an air one. But the design of this system is much more complicated.

It includes:

1. Cooling jacket
2. Water pump
3. Thermostat
4. Radiators
5. Connecting pipes
6. Fan

In this case, the main working element of such a system is a special liquid - with the help of which heat is removed. Previously, ordinary water was used instead, but due to the low temperature threshold of freezing and the formation of scale, water was gradually abandoned.

1. Cooling jacket

The cooling jacket is a special system of channels in the cylinder block and the block head through which fluid moves. If we consider everything in a simple way, then it looks like this: there is a block in which the cylinders are installed, as well as the main components and mechanisms. A shell is made on top of this block, and the space between them is used as channels for fluid movement. This design allows the fluid to wash over the cylinders, pass next to the units installed in the block and the head, which ensures heat removal from them.

2. Pump

It looks like water pump

A water pump is installed in the cooling jacket. It consists of a drive gear (pulley) and an impeller, which is placed inside the shirt, mounted on one axis. It is driven from the crankshaft using a belt.

It is the water pump that circulates the fluid through the system. Receiving rotation from the crankshaft, the impeller forces the fluid to move through the channels of the jacket.

3. Radiator

In this case, antifreeze circulates not only in the shirt. If this were the case, then the liquid would have nowhere to give heat, that is. To prevent this from happening, it is included in the design.

It is a structure of two tanks - one is supplied with liquid from the jacket, and from the second it returns back. These tanks are interconnected by a large number of tubes through which the liquid moves between them. So that the radiator is made of metals with high thermal conductivity (copper, aluminum, brass). Also, in order to increase heat transfer between the tubes, special tapes are located, laid in a certain way and having a large number of points of contact with the tubes.

The liquid passing through the tubes gives off some of the heat to the tapes. The air passing through the radiator collects heat and removes it to the environment. To ensure good air flow, the radiator is installed in the front of the car. The radiator with the cooling jacket is connected by means of rubber pipes.

Separately, we note that thanks to the liquid system, it was possible to provide and. For this, another radiator was included in the cooling system, which was placed in the cabin. Structurally, it is the same as the main radiator, but smaller in size. The air flow for it is created using an electric motor with a fan.

Video: Engine overheating. Consequences of overheating.

4. Thermostat

The cooling system must ensure the fastest possible output of the power plant to the optimal temperature regime. And to ensure this, a thermostat is included in the design. To understand what it is for - a little theory.

If the design of the system consisted only of a jacket and a pump, then the engine would overheat very quickly, since the liquid moved only through the channels in the block and there would be nowhere to remove heat.

The device and principle of operation of the thermostat

To avoid this, a radiator was included in the design. But due to its presence, the volume increased, besides, the purpose of the radiator is to remove heat, so the engine will reach the desired temperature for a very long time, especially in winter period.

To ensure a quick access to the required temperature, the cooling system was divided into two rings - a small one (only the cooling jacket and a pump are involved) and a large one (jacket + pump + radiator).

The thermostat is also engaged in the division into rings. It is a valve that is triggered by an increase in temperature. On different cars its response temperature is different, but in general it works in the range - 85-95 degrees. WITH.

The thermostat housing is usually located on the cylinder block near the channel leading to the radiator. While the temperature of the motor is low, the thermostat closes this channel and the liquid moves only along the jacket. As the temperature rises, this valve begins to open gradually, letting the liquid through the large ring, with the involvement of the radiator. When a certain temperature value is reached, it opens completely, and the liquid already moves only along the large ring.

5. Fan, sensors

The principle of operation of the cooling fan

It so happens that the air flow is not enough to ensure normal heat removal from the radiator. For example, this happens in a traffic jam when the engine is constantly running, but there is no oncoming air flow, since the car is immobilized.

To prevent the liquid from overheating, a fan is used to create a forced air flow. It is located behind the main radiator and is driven by an electric motor. Its inclusion in work is carried out due to the installed in the radiator temperature sensor.

Additionally, the design also includes a temperature one, which transmits temperature data to dashboard in the cabin, so the driver can constantly monitor the temperature of the engine and notice the appearance of a malfunction in time, which is why the temperature of the engine "went up".

The main malfunctions of the cooling system

There are not so many malfunctions in the engine cooling system, but the consequences from them can be very serious. The main ones are:

• Leakage of coolant;
• Malfunction of the pump, thermostat;
• Damaged sensor wiring.

Video: All causes of engine overheating and boiling. Elimination of the causes of overheating of the VAZ NIVA engine

Fluid leakage can occur due to breakdown of the cooling jacket, cylinder head gasket, rubber pipes, radiator, or due to unreliable fastening of the joints.

It is not difficult to identify this malfunction, since as a result of a leak under the car, a puddle of coolant will form. If the leak is not eliminated in a timely manner, then most of the coolant may leak out, and the system will no longer be able to maintain the temperature regime.

Pump failure is often associated. This is accompanied by traces of smudges on the drive side, increased noise during engine operation, and uneven wear of the drive belt.

If the pump is not replaced in a timely manner, then there is a possibility that it will jam and break drive belt, and this is already fraught with quite serious problems, since often the timing belt is also put into operation with this belt.

The problem with a thermostat is usually that it gets stuck in one position. Because of this, the transfer of liquid between the rings is not carried out, it moves either only in a small or in a large circle.

Damage to the wiring or sensors leads to the fact that the readings to the dashboard are not transmitted or do not correspond to reality, and the fan does not turn on at the required time or it runs constantly, which is why the temperature regime is violated.

»Car engine cooling system, principle of operation, malfunctions

The car's engine cooling system needs to be checked periodically. Many significant car malfunctions are caused by engine overheating. The temperature of the combustion air-fuel mixture reaches several thousand degrees. Accordingly, a large amount of heat is generated, which must be removed so as not to overheat the motor, which can lead to serious problems.

Engine overheating problems

Inefficient operation of the cooling system can lead to an excess of the operating temperature of the pistons, a decrease in the thermal clearance between the piston and the cylinder walls down to zero. This causes the piston body to rub against the cylinder walls, the formation of scratches, scoring. Also when overheating motor oil loses its lubricating properties, the oil film is broken. This can cause the engine to jam.

Overheating of the cooling system and the engine is accompanied by different expansion of the cylinder head, block and mounting bolts due to different materials, which leads to a curvature of the mounting surface of the head, pulling out of the bolts, and cracking of the valve seats. It is clear that after such changes, it is difficult, and sometimes impossible, to repair the engine.

Engine coolants

A properly working cooling system must prevent overheating, but for the system to function properly, the use of high-quality coolant is required. Non-freezing at low temperatures technical fluids are called antifreezes (from the English antifreeze). Today, antifreeze products are generally made on the basis of monoethylene glycol, which is a thick liquid with a boiling point of about 200 ° C.

The task of the coolant is not only to cool the engine, but also to transfer heat for heating the passenger compartment, heating the fuel in winter. The vehicle's coolant must meet the following requirements:

• not freeze in the entire range of engine operating temperatures;
• have high values \u200b\u200bof heat capacity and thermal conductivity;
• do not form foam;
• do not corrode plastic and rubber pipes;
• do not damage the seals;
• lubricate, protect parts of the cooling system and engine from corrosion;
• do not deposit scale and other deposits of various kinds on the inner walls of the working surface of the cooling system

It is customary to distinguish between the concepts of "antifreeze" and "antifreeze". It is believed that antifreeze is a finished product, and antifreeze is a concentrate. Although, of course, the composition is one and the same, just with a different name.

Automotive antifreezes are painted in noticeable, bright colors:

• green,
• orange, or shades of red
• light blue (blue),
• turquoise

This is done for the sake of safety, because antifreeze is very poisonous. With use, the liquid loses the necessary properties - lubricating and anti-corrosion parameters are gradually lost, and the tendency to foam increases.

Important: The service life of antifreezes is within 2-7 years.

After starting the car, together with the engine, the pump of the cooling system begins to rotate (also called a pump, water pump) unless of course there is no electronic connection of the pump. In rotation, the pump is driven by a timing belt (timing) or using a belt attachments - it depends on the design of the particular engine model. The impeller of the water pump, while rotating, pumps coolant through the system. To quickly reach the operating temperature, a small circuit is provided in the car's cooling system, that is, the fluid circulates only inside the engine, the thermostat is closed, antifreeze is not supplied to the radiator.

As soon as the engine warms up to a certain temperature, the thermostat opens, passing antifreeze or antifreeze along the large circuit of the cooling system. The liquid passes through the radiator where it is cooled. The radiator is cooled by outside air passing freely through the radiator grill, or forced by a fan. After cooling in the radiator, the antifreeze is supplied to the engine cooling system, takes some of its heat and is directed again in a large circle.

A fan switch is installed in the radiator, which, when a certain temperature is reached, turns on forced airflow or changes the fan speed. When the rotation speed changes, the amount of air passing through the radiator honeycomb changes, and accordingly, the liquid cooling efficiency is regulated. As the liquid in the radiator cools, the fan turns off. If the antifreeze becomes colder than the response value, the large circuit is closed, - circulation again occurs in a small circle.

Some cooling systems use several temperature sensors, the location of the sensors:

• on the radiator of the cooling system,
• on the cylinder head,
• directly on the thermostat housing.

This scheme of work is basic, but manufacturers are constantly improving cooling systems. Some cars do not have sensors for switching on the fan, which is started by a signal from the engine control unit, depending on the readings of the temperature sensor. Thermostats can also be controlled by the "brains" of the motor, opening and switching circuits not automatically, but by a control signal. In some models, solenoid valves are installed on the pipes leading to the heater, which regulate the coolant supply to the heater radiator. If they fail, these valves can cause problems in the cooling system.

One of the improvements to the cooling system is an electronically controlled pump, or rather a pump drive, which, depending on the engine temperature, connects the pump or disconnects it, thereby contributing to more efficient thermal regulation and faster heating of the vehicle cooling system.

Diagnostics of malfunctions of cooling systems

Engine overheating - this is a mode of operation that is caused by the boiling of the coolant. However, overheating is not the only problem. Operating the motor at a constant low temperature is also harmful, since the operating temperature must be maintained at a certain level. Cold engine consumes more fuel, does not work with the best efficiency, is subject to increased loads due to the increased viscosity of the lubrication system.

Damage to the thermostat, fan, thermal relay and sensors interferes with the proper functioning of the cooling system. If signs of a violation of the temperature regime are detected on time and the occurrence of fatal malfunctions has not occurred, then the repair, most likely, will not be too long and expensive. Therefore, all specialists are advised to monitor temperature conditions motor operation.

Diagnose problems and faults with a cold engine. First you need to check the correctness of the articulation of the pipes and pipes, the assembly of other elements of the cooling system, especially if the car was repaired shortly before the problem occurred. Perhaps this is ridiculous, but there are many known examples when the cooling does not work correctly due to assembly errors.

Some of these cases:

• after the engine bulkhead, the crankcase ventilation hose is connected to the coolant expansion tank;
• a "non-native" cooling fan is installed, due to the incorrect position of the blades of which the air is directed in the wrong direction;
• the fan impeller blades turn freely on the shaft;
• the sensor or fan connectors are oxidized, loose, or damaged.

It will also be useful to conduct an external inspection of the radiator, perhaps it is dirty, honeycomb clogged. Sometimes too tight engine protection, blocking the path of air from below, can negatively affect. A small accident, which only led to a breakdown of the bumper, can lead to overheating - special guides are formed in the bumper along which air passes to the engine ( VW Passat B5).

After a visual inspection of the cooling system, you need to check the level of antifreeze, the serviceability of the valves of the radiator plug or tank, the tightness of the hoses and pipes. It makes sense to decide what is poured into the system - antifreeze or just water.

If the first steps helped to calculate any malfunctions of the engine cooling system, they must be eliminated or taken into account when making a "diagnosis". When adding liquid, you need to remember that not every car can simply add antifreeze, and that's it. For example, in some BMWs, when adding coolant, the ignition should be turned on, and the stove settings should be set to maximum in order for the heater solenoid valves to open.

If you suspect that air has entered the cooling system, you need to unscrew the special plugs designed to release the air. They are usually located at the highest point in the system. If the machine has an expansion tank, you can check if the fluid is circulating. If, during the systematic warming up of the engine, cold air enters the passenger compartment from the air ducts of the heater, this is the first sign of an air "bubble" in the system.

If the thermostat is known to be in good working order, after warming up the radiator, its lower and upper branch pipe should have approximately the same temperature. Big difference temperatures of these pipes indicates poor circulation of antifreeze through the radiator.

After a certain period of time after opening the thermostat, as the response temperature is reached, the radiator cooling fan should turn on. If the system contains a non-electric fan, check the magnetic clutch close sensor or viscous clutch function. The possibility of stopping and holding the fan by hand can be considered a sign of a malfunction of the viscous clutch. Be sure to be careful! Attempt to stop with a soft object to eliminate the possibility of hand injury or damage to the impeller. The air flow should be directed towards the engine, in the correct case.

Cooling system pressure the car increases in proportion to the warming up of the engine and gradually falls as it cools. If the upper pipe, suitable for the radiator, swells from an increase in the engine speed, then it makes sense to make sure that some of the gases from the engine do not enter the system. This happens if cylinder head gasket punched between the cooling channel and the cylinder or if the block head itself is damaged. One of the signs of this problem is an oil film in the expansion tank. Also, gases are signaled by bubbles that appear in the antifreeze during engine operation.

There are many examples of how a malfunctioning cooling system led to serious, up to engine replacement, problems for the owner. The main conclusion should be made one thing - there are no trifles and unimportant malfunctions in the car. You need to notice all the changes, analyze them, draw the right conclusions. If the car owner does not understand this, the car should be regularly serviced by good specialists.

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