The cooling system is used to maintain the operating temperature of the engine

The heat generated in the engine is absorbed by the coolant passing through the channels in the block and the cylinder head.

This heat is then removed from the coolant by air as it passes through the radiator.

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Coolant enters the water pump located under the cover of the front timing gears and creates pressure in the cooling system and enters the holes in the upper cavity of the cylinder block and the cylinder head gaskets.

They are made around each cylinder and between the cylinders.

Coolant enters the cylinder head, flowing around the valve bridge and the injector locations.

It then flows to the exhaust ports in the cylinder head through the OEM connections and into the thermostat housing.

Особенности системы охлаждения ГАЗель Некст

Until the engine warms up to the thermostat opening temperature, coolant is supplied through the bypass pipe to the water pump inlet.

As soon as the engine warms up to the opening temperature of the thermostat, it will open and coolant will begin to flow through the radiator. This will block the bypass channel through which it will flow to the water pump.

The thermostat maintains a temperature between 82 - 95˚ C.

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Radiator with tubular-tape core and polymeric material tanks.

In the right tank there is a hole with a plug for draining fluid from the cooling system.

Особенности системы охлаждения ГАЗель Некст

An expansion tank is installed to compensate for the coolant volume depending on the temperature.

There are liquid level marks on the tank body.

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Tank cap with a vent valve that maintains overpressure in the system, allowing the coolant to start boiling up to 120˚

The water pump is installed on the front cover of the cylinder block and is driven by the timing belt.

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The thermostat is installed in a housing fixed to the cylinder block. Closed at 82˚, opens at 95˚

A fan with a plastic impeller is installed on the front cover of the viscous coupling and is attached to it with four bolts

Особенности системы охлаждения ГАЗель Некст

The fluid-friction clutch of the fan (viscous clutch) is installed on a support and attached to it with a threaded bushing

The liquid-friction clutch allows you to change the fan speed depending on the temperature of the air flow passing through the radiator of the cooling system.

So, at low temperatures, the fan speed is minimal, as the temperature rises, its frequency increases.

The rotor of the clutch is not rigidly connected to the casing on which the fan is installed, and the moment is transmitted due to the internal friction of the working fluid.

The fan speed changes due to the flow of liquid volumes through the inner cavities of the clutch.

The overflow of liquid occurs depending on the opening or closing of the internal channels of the coupling and is regulated by the movement of the plate valve.

Depending on the temperature, the valve position changes under the influence of a bimetallic spring.

Особенности системы охлаждения ГАЗель Некст

The bimetallic spring is installed outside the clutch at its front.

The rotational speed of the fan installed on the viscous coupling housing increases as the air temperature rises and becomes equal to the rotational speed of the engine crankshaft.

The cause of engine overheating, especially when driving in difficult road conditions or a traffic jam, may be a failure of the fluid-friction clutch of the radiator fan.

To check the clutch when the engine is not running, check the fan for ease of movement.

Check that the fan does not have strong axial and radial play.

Make sure there are no traces of oil on the clutch. If there are traces of oil, the clutch must be replaced.

With the engine warm (the hood is closed), set the engine crankshaft speed to approximately 3000 rpm.

The fan impeller will rotate at a low speed due to a small residual torque.

When the coolant temperature is 80-85˚C, the clutch should start working. The fan speed will increase dramatically (usually indicated by increased noise).

Особенности системы охлаждения ГАЗель Некст

The pre-heater-preheater is installed in the right cavity of the front bumper (view in Figure 13 with the front bumper removed) on vehicles with the Comfort-2 configuration.

Due to the design features of the diesel engine, when it is idle for a long time (especially in the cold season), the coolant temperature gradually decreases below normal, which, among other things, reduces the efficiency of the heater.

The pre-heater eliminates this disadvantage and at the same time performs the function of a pre-heater.

The unit runs on diesel fuel, which is supplied to it from the fuel tank by a special metering pump.

Особенности системы охлаждения ГАЗель Некст

The metering pump is installed on the inner side of the vehicle frame and is connected to the fuel tank and the preheater combustion chamber by special plastic fuel lines.

Checking the tightness of the cooling system connections

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We look at the presence of coolant in the expansion tank

Checking the radiator supply hose

Особенности системы охлаждения ГАЗель Некст

Checking the radiator outlet hose

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We inspect the attachment points of the hoses to the water pump

Inspecting the attachment points of the hoses to the thermostat

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We inspect the attachment points of the hoses to the heater tap

We check the attachment points of the hoses to the pipes for draining the liquid from the heater

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Liquid supply to the exhaust gas recirculation heat exchanger

And the heater

Особенности системы охлаждения ГАЗель Некст

If you notice a leak, you need to remove the hose.

Hose leaks are usually caused by corrosion of the sealing surface of the nozzles.

You need to clean this area and apply sealant before installing the hose.

Possible malfunctions of the cooling system

  • - Cause of malfunction

Debugg

Coolant leaks:

  • - External coolant leaks

Check for coolant leaks from hoses, drain taps, water manifold, jumper tubes, expansion plugs and pipe plugs, fittings, coolant supply and return lines, EGR cooling system ventilation, turbocharger coolant supply and return lines, Coolant supply and return lines, EGR valve, EGR cooler and valve, radiator heat exchanger, compressor and cylinder head gaskets, oil cooler, water pump seal and OEM parts that are connected to the engine cooling system. If necessary, pressurize the cooling system.

  • - The cap of the expansion tank is incorrectly selected or designed for low pressure

Check the expansion tank cap or replace it

  • - Deformation, clogging or leaks in the coolant hose

Check hoses

  • - Clogged, clogged or improperly routed coolant or air outlet lines

Check that the coolant lines are correctly routed and clogged.

  • - Air enters the cooling system

Make sure there is no air or combustion products in the cooling system

Gradual or sudden overheating of the coolant:

  • - Electronic DTCs active or a large number of passive DTCs

Read fault codes and diagnose with INSITE kit

  • - The insulating cover or the front apron of the radiator is closed

Open the insulating cover or the front apron of the radiator

  • - Damaged or clogged radiator fins

Check radiator fins

  • - The coolant level is below normal

Check the coolant level. Check for leaks

  • - The concentration of antifreeze in the coolant is not correct

Check the concentration of antifreeze in the coolant.

Add antifreeze or water to bring the concentration back to normal.

  • - Damaged or missing fan shroud or air recirculation deflectors

Check fan shroud and recirculation air deflectors.

  • - Fan drive belt damaged or loose

Check the fan belt. Replace the belt if necessary.

  • - Faulty fan drive or fan control system

Check that the drive and fan control system are working properly.

  • - Faulty gauge or coolant temperature sensor

Check the health of the pointer and temperature sensor. Repair or replace as necessary.

  • - The expansion tank cap valve does not work correctly

Check or replace the expansion tank cap

  • - Thermostat is incorrectly selected or defective

Check the conformity of the thermostat and its serviceability

  • - The presence of dirt, scale or sediment in the cooling system

Clean the cooling system

  • - The coolant is contaminated with oil

Check for oil leakage into the cooling system, replace the coolant.

  • - Faulty water pump

Check the pressure in the cylinder block. Replace the water pump if necessary

Coolant temperature below normal:

  • - Thermostat is incorrectly selected or defective

Check the thermostat in the catalog, check its functionality

  • - Faulty fan drive or fan control system

Check that the drive and fan control system are working properly.

  • - Engine idling too long

Do not leave the engine idling for a long time.

Coolant in oil:

  • - Defective oil cooler

Check the oil cooler

  • - Internal coolant leaks

Pressurize the cooling system and search for internal coolant leaks

  • - Leaky cylinder head gasket

Check the cylinder head gasket

  • - Cracks or pores in the cylinder head

Pressurize the cylinder head

  • - Cracks or pores in the cylinder block

Check the cylinder block