VAZ 2109 coolant circulation

The engine cooling system is an important structural element of a car. Its malfunction leads to poor heating of the engine to the required temperature, which causes poor operation of the stove, loss of power and reduced service life of the power unit. On the other hand, the engine system may overheat, which causes breakdown of the cylinder-piston group.

cooling system vaz 21099 carburetor diagram

VAZ 2199 cooling system injector

1 – element in the form of a plug for the expansion tank; 2 – expansion tank; 3 – hose for draining liquid from the pipe; 4 – hose passing between the radiator and the expansion tank; 5 – hose leading from the radiator; 6 – tank to the left of the radiator; 7 – aluminum tube; 8 – plug systems; 9 – tank to the right of the radiator; 10 – drain plug; 11 – middle of the radiator; 12 – casing for electric fan; 13 – plastic wings of the electric fan; 14 – electric motor; 15 – toothed pump pulley; 16 – pump impeller; 17 – camshaft drive belt; 18 – engine block; 19 – pump pipe; 20 – radiator hose with supply function; 21 – heater radiator hose with drain function; 22 – hose supplying coolant to the throttle pipe; 23 – exhaust pipe; 24 – hose for refilling; 25 – heater radiator hose with supply function; 26 – thermostat; 27 – coolant temperature sensor; 28 – coolant level indicator sensor.

The cooling system of VAZ 21093,2109,21099 removes heat from engine parts subject to heating through forced circulation. And the injector doses the flow of fuel. Structurally, the VAZ injector cooling system consists of:

coolant pump,
monoblock thermostat,
electric radiator fan,
radiator with expansion tank,
pipelines, pipes, drain plugs.

How the cooling system of VAZ 21093,2109,21099 works

The cooling pump drive is driven by the timing belt. The total volume of the system, including the stove, is 7.8 liters. Temperature control is carried out using a sensor installed on the cylinder block jacket. The temperature indicator is displayed on the instrument panel.

During operation of the VAZ engine, liquid from the block jacket passes into the radiator (where heat is removed) or into the thermostat (short circuit - to warm up the engine). Next, the liquid is pumped into the cooling jacket of the VAZ injector power unit. The pipelines circulate and heat the fuel mixture in the intake manifold and throttle valve area.

The cooling system communicates through pipes with the radiator of the interior heater of VAZ 21093,2109,21099. The coolant pump is centrifugal. The system is equipped with a collapsible tubular plate radiator with plastic tanks.

The internal surface of the radiator is increased by using aluminum tubes and cooling plates; it does not have a filler hole; topping is done in the expansion tank. Which also has a sensor for turning on the electric fan. The tank has a filler plug with valves (inlet and outlet). To drain the cooling liquid from the system, unscrew the drain plugs of the tank, cylinder block, and radiator.

CO elements

The cooling system used on the VAZ 2109 operates at low pressure. After studying the components, you will learn about their functions and features.

Element	Peculiarities
Pump	It ensures efficient, stable operation of the system. The pump is used to pump cooling liquid, which facilitates its movement along a small or large circuit. The pump consists of a housing, an axle with a pulley located on it connecting to the timing belt, and a plastic impeller. The latter allows the coolant to move. A bearing lubricated with antifreeze is installed between the axle and the housing. Because of this, the presence of water in the system is unacceptable. Otherwise the bearing will collapse
Thermostat	Plays an important role, although in practice the CO can do without it. The system works in such a way that the engine first warms up to operating temperature (about 90 degrees Celsius), after which it is necessary to further cool the liquid. First, the coolant moves along a small circuit - through the jacket into the stove radiator, and then the excess is returned to the expansion tank. But when the operating temperature is reached, the thermostat begins to move the coolant flow into the radiator. A thermostat can be called a mechanical valve that automates the operation of the CO. Hot liquid acting on the bimetallic plate of the thermostat deforms it, which is why the coolant supply valve to the radiator can open or close
Radiators	The SO VAZ 2109 has a pair of radiators - a stove and a main one. Their design is the same regardless of whether you have a carburetor or an injector. At the same time, there is a noticeable difference between the main and stove radiators. The main one is larger in size, they perform different functions, plus the main one has holes for a sensor that turns off the fan. If the stove radiator can be connected to operation at any time by pressing a button, then the main radiator operates in automatic mode when certain operating parameters of the CO are achieved
Expansion tank with plug	A constant pressure is maintained inside the CO, which ensures efficient coolant circulation. On the VAZ 2109, the system is designed so that at high pressure the liquid does not boil when it reaches 100 degrees, but at higher parameters. This increases engine reliability. Pressure support is provided by an expansion tank with a cap and a pair of mechanical valves - inlet and outlet. The inlet valve is activated if the pressure drops to 0.13 atm. The second one comes into operation at the moment when the pressure is above 1.3 Atm.
Pipes, clamps	Do not underestimate the role of pipes and clamps in the CO, since it is through them that the coolant is supplied to the required points. When replacing, under no circumstances use cuttings from other pipes that do not correspond to the parameters used previously. Plus, if at least one pipe is damaged, everything will have to be replaced as a set, and not separately
Sensors	Looking at the radiator (main), below you will see a pair of wires and a yellow device twisted into the hole. This is the electric fan switch sensor. Another sensor is also located in the motor block - temperature. It transmits information to the electronic control unit or pointer
Electric fan	As a standard, the VAZ 2109 is equipped with fans equipped with 4 blades. But if you want to achieve greater efficiency, we recommend replacing it with a 6-blade electric fan. This will increase the air flow while maintaining the original power and rotation speed. Heat from the heater radiator begins to flow inside the cabin when the tap is opened. There is a fan under the hood connected via a rheostat. It regulates the rotation speed of the impeller. The switch is located under the audio system, near the heater damper control levers.

Thermostat

When planning to replace an electric fan, work should be done through the engine compartment. No need to dismantle the snail .

CO pump

Features of the fan and thermostat VAZ 21093, 2109, 21099

The electric fan includes an electric motor and a four-blade impeller, the blades of which have a variable angle of inclination and pitch to reduce noise levels. To increase efficiency, the VAZ fan system is equipped with a casing attached to brackets.

The electric fan is mounted on rubber bushings. The fan is triggered by a signal from a sensor installed in the radiator tank. In this case, the contact closure temperature is approximately 99'C, and the fan shutdown temperature is 94'C.

The system thermostat provides priority warming up of the engine and regulates the thermal regime. The optimal coolant temperature is within 90-98'C. The thermostat includes a body and a cover, rolled together with the valve.

Description of design

The cooling system is liquid, closed type, with forced circulation. The tightness of the system is ensured by the inlet and outlet valves in the expansion tank plug. The exhaust valve maintains pressure in the system when the engine is hot (due to this, the boiling point of the liquid increases and steam losses are reduced), it opens at a pressure of about 1.1 kgf/cm2. The intake valve opens when the pressure in the system decreases relative to atmospheric pressure by 0.03–0.13 kgf/cm2 (on a cooling engine). The thermal operating conditions of the engine are maintained by a thermostat and an electric radiator fan.

The coolant pump is a vane, centrifugal type, driven from the crankshaft pulley by a camshaft drive timing belt. The pump housing is aluminum. The roller rotates in a double-row bearing with a “lifetime” supply of lubricant. The outer ring of the bearing is locked with a screw. A toothed pulley is pressed onto the front end of the roller, and an impeller is pressed onto the rear end. The distance from the mating surface of the pump cover to the outer end of the pulley should be 52±0.5 mm, and to the outer (facing the block) end of the impeller - 39.8±0.1 mm. A thrust ring made of a graphite-containing composition is pressed to the opposite end of the impeller, under which there is an oil seal. If the pump fails, it is recommended to replace it as an assembly.

The redistribution of liquid flows is controlled by a thermostat with a solid heat-sensitive element. On a cold engine, the thermostat valve closes the pipe leading to the radiator, and the liquid circulates only in a small circle (through the thermostat bypass pipe), bypassing the radiator. On VAZ-2108, -21081, -21083 engines, the small circle includes the heater radiator, intake manifold, carburetor throttle assembly heating unit (on engines with semi-automatic starting - and the liquid chamber of the semi-automatic starting device). On the -2111 engine, fluid is supplied to the heater and the throttle assembly heating unit.

Features of the VAZ injector cooling system

Cooling in cars 21093,2109,21099 is liquid, but you need to understand that the radiator is cooled by the flow of incoming air and a fan, which increases the cooling intensity. Also, part of the heat is removed by the car's interior heater radiator at low temperatures.

The expansion tank is designed to compensate for the volume of liquid when heating, to top up and control the level of antifreeze.

The thermostat system provides temperature control, preheating of the VAZ engine, initial heating of the interior in winter, and only then ensures the inclusion of a large cooling circuit.

The temperature sensor provides control of the cooling system, allows you to monitor the engine temperature and regulate the operation of the fan.

The entire operating cycle of the cooling system is controlled using a power unit control system that takes into account all temperature parameters. It determines the optimal switching conditions and operating time of the structural elements of the system.

Diagnostics of the engine cooling system of VAZ 21093, 2109, 21099 and identification of faults

If problems arise with the engine cooling system, the causes should be determined, starting with the most probable and simple ones:

If there is a coolant leak, first check the fluid level in the system. In cars 21093,2109,21099 this is done using the level indicator or when inspecting the expansion tank.
If the level has changed, inspect the engine compartment for leaks. As a rule, the main reasons are: worn pipes and clamps, damaged engine cooling radiator or heater.
In case of jet changes in the tank at 3000 rpm. It is necessary to check the fluid circulation. To do this, open the cap of the expansion tank and determine the uniformity of antifreeze flow. The causes of poor circulation may be a clogged system or a malfunction of the circulation pump.

What should the temperature be?

The temperature arrow tends to the red zone - soon overheating

According to the international automobile convention of December 1, 1992, where 92 representatives of the auto industry gathered, it was decided to establish a single standard for engine operating temperature.

This indicator is 90 degrees Celsius with a maximum permissible deviation of no more than 3 degrees Celsius.

With the development of the automotive industry and a sharp leap in technology in the 2000s, in 2004 it was decided to revise this indicator. So, having considered all the facts and analyzed the design features of many cars, it was decided to establish a floating indicator with marginally acceptable standards, which, today, is 85-105 degrees Celsius.

Operating range on the VAZ-2114

If we consider cars produced at the AvtoVAZ plant, including the VAZ-2114, then the operating temperature range for engines is considered to be 87-103 degrees Celsius. If we consider this issue from the point of view of functionality, then this is the optimal indicator.

If the temperature drops below the limit level, then the Samara-2 engine loses dynamics and power, and if it is higher, it can simply boil and cause great damage. Therefore, if malfunctions associated with the cooling system occur, they must be eliminated as soon as possible.

Cooling system design

Before considering cooling system malfunctions, as well as methods for eliminating them, novice motorists should study the cooling system.

So, let's look at what elements it consists of:

Cooling system design

Main malfunctions and ways to solve them

The operating temperature of the engine is directly affected by the health of the cooling system.

Almost every node can affect changes in this indicator in both directions, so it is necessary to monitor its serviceability and prevent changes. It is temperature fluctuations that can lead to breakdowns of other engine systems. So, let's look at the components of the cooling system, their malfunctions and solutions.

Cooling radiator

Dirty engine radiator

The radiator is considered one of the most reliable parts. There are not many reasons that can lead to product failure, but they can be prevented. A clogged part can lead to an increase in engine operating temperature, but regular cleaning of the internal and external surfaces will bring it back to normal.

The formation of cracks can cause the radiator to leak, but this problem can be dealt with. There are two methods to solve the problem: soldering the surface or replacing the product completely. Thus, repair and restoration work normalizes the operation of the part, as well as the operating temperature in the system.

Pipes

Dirt and rupture of the SOD pipe can lead to a change in the operating temperature of the motor

The cooling system pipes can directly affect the temperature increase in the system. This is due to the fact that if cracks or delaminations form in them, it may happen that the coolant begins to leak out. In turn, the lack of “cooling” will lead to an increase in temperature, which can affect both the operation of the main power unit and increased wear.

Water pump

Leaks on the cylinder block from the timing side indicate that the pump has failed

The water pump or water pump should drive coolant through the system , but if this unit breaks down, low pressure can lead to slow cooling, which in turn will increase the operating temperature of the engine. Often, the water pump will simply leak and driving the car will no longer be possible.

The fault can be easily treated by replacing the part.

Thermostat

Thermostat operation diagram at different temperatures

Causes of VAZ engine overheating

A faulty thermostat can cause the engine to overheat. If on a warm engine the upper pipe is hot and the lower pipe is cold, the thermostat is jammed and the antifreeze flows only in a small circle. Or the thermostat will only turn on a large circle, which will not allow the VAZ engine to warm up to the required operating temperature. In this case, the thermostat should be replaced.
Another reason for excessive engine heating may be airing of the cooling system; in this case, the system must be pressed and air removed from all cavities.
At high temperatures, the fan does not turn on - there is a problem with the temperature sensor, fan relay or the wiring harness to it.
Sometimes the radiator honeycombs become clogged, which sharply reduces the intensity of heat transfer. It is necessary to thoroughly clean the radiator; it must be done carefully to avoid damage to the cells.

These are the main reasons that affect the quality operation of the VAZ 21093,2109,21099 engine cooling system; with their help, you can identify and eliminate malfunctions, ensuring reliable and durable operation of the engine.

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When parts need to be replaced

When is it necessary to replace the VAZ 2109 coolant and cooling system elements? The fluid must be changed regularly after a certain period of use. Parts are not changed periodically, but only after a breakdown. One of the causes of breakdowns is overheating due to a malfunction of some element in the cooling system. The following signs of engine overheating can be observed:

the coolant temperature is higher than normal and can exceed 120ºС, this is indicated by a special sensor;
there is a sharp drop in engine power;
the sound of the engine changes, a ringing metallic knock appears;
oil consumption increases;
Coolant consumption increases significantly.

As a result of overheating, after you open the hood, you will see deformed parts - bent cylinder head, gasket edging, burnout of some parts. Repairing deformed parts does not make sense; they need to be replaced.