Engine cooling system UMZ-42164-80
Rice. 12 Cooling system diagram.
1 - interior heater radiator; 2 - radiator valve; 3 - water jacket; 4 - block head; 5 - gasket; 6 - inter-cylinder channels for the passage of the coolant; 7 - thermostat; 8 - thermostat housing; 9 - branch pipe of the thermostat body (large circle of circulation); 10 - steam outlet pipe; 11 - expansion tank; 12 - filler neck plug; 13 - mark "min"; 14 - coolant temperature sensor; 15 - branch pipe for removing liquid from expansion tank; 16 - cooling system pump; 17 - water pump impeller; 18 - cooling system fan; 19 - two-way radiator of the cooling system; 20 - water pump branch pipe; 21 - radiator drain plug
The first control loop consists of an automatically operating thermostat that regulates the amount of fluid entering the radiator. Depending on the position of the thermostat valve, the ratio of fluid flows passed for cooling to the radiator and returned back to the engine changes. The second control loop is realized by controlling the operation of the electromagnetic clutch of the fan drive, due to which the amount of air passing through the radiator grilles changes. The switching on and off of the electromagnetic clutch is carried out by the relay according to the commands coming from the controller.
During operation, coolant must be poured and topped up into the cooling system through the expansion tank 11 by opening the filler cap 12. The liquid vapors and evolved air formed in the system are discharged from the radiator and thermostat housing through a steam pipe 10. In order to avoid cavitation during pump operation 16, its suction cavity is connected to the expansion tank by means of a branch pipe 15.
For normal operation of the engine, the temperature of the coolant at the outlet from the head must be maintained within the range of plus 81 ° - 89 ° C.
A short-term operation of the engine at a coolant temperature of 105 ° C is permissible. Such a mode can occur in the hot season when the car is moving with full load on prolonged ascents or in urban driving conditions with frequent accelerations and stops.
Maintaining the operating temperature of the coolant is carried out using a single-valve thermostat with a solid filler T-118-01 installed in the housing.
When the engine warms up, when the coolant temperature is below 80 ° C, a small circle of coolant circulation operates. The thermostat valve 7 is closed.
The coolant is pumped into the cooling jacket 5 of the cylinder block 6 by a water pump, from where, through the holes in the upper plate of the block and the lower plane of the cylinder head, the liquid enters the cooling jacket of the head 3, then into the thermostat housing 14 and into the supply branch of the interior heating radiator 1. Depending from the position of the valve of the interior heating valve 2, the coolant either through the heating radiator or bypassing it enters the connecting pipe and then to the inlet of the water pump. The two-way radiator 19 of the cooling system is disconnected from the main flow of the coolant. The circuit of fluid circulation implemented in this way makes it possible to increase the efficiency of heating the passenger compartment when the fluid moves in a small circle (this situation can be maintained for a long time at low negative ambient temperatures).
When the liquid temperature rises above 80 ° C, the thermostat valve opens and the coolant circulates in a large circle through the two-way radiator.
For proper operation, the cooling system must be completely filled with liquid. When the engine warms up, the volume of liquid increases, its excess is pushed out due to the increase in pressure from the closed circulation volume into the expansion tank. When the temperature of the liquid drops (after the engine stops working), the liquid from the expansion tank is returned to the closed volume under the action of the resulting vacuum.
The coolant level in the expansion tank should be 3-4 cm above the "min" mark. Due to the fact that the coolant has a high coefficient of thermal expansion, and its level in the expansion tank changes significantly depending on the temperature, the level should be checked at a temperature in the cooling system of plus 15 ° C.
The tightness of the cooling system allows the engine to operate at a coolant temperature in excess of + 100 ° C. When the temperature rises above the permissible level (plus 105 ° C), the temperature alarm is triggered (a red lamp on the instrument panel). When the temperature warning lamp comes on, the engine must be stopped and the cause of overheating eliminated.
The reasons for overheating can be: insufficient amount of coolant in the cooling system, weak tension of the coolant pump drive belt.
A warning. Do not open the expansion tank cap when the coolant in the cooling system is hot and under pressure, otherwise serious burns may occur.
The coolant is poisonous, so avoid getting it into the mouth or on the skin.
The coolant pump is shown in fig. 13.
Thermostat housing is die-cast from aluminum alloy. Together with the housing cover, it distributes the coolant in the outer part of the engine cooling system, depending on the position of the thermostat valve (Fig. 14)
Rice. 13. Coolant pump:
1 - hub; 10 - pulley; 3 - case; 4 - retainer; 5 - bearing; 6 - fitting for draining the coolant from the heating system; 7 - cover; 8 - impeller; 9 - oil seal; 10 - control hole.
Rice. 14. Scheme of the thermostat: a - the position of the thermostat valve and the direction of the coolant flow when the engine is warming up; b - after warming up.
1 - thermostat housing; 2 - fitting of the interior heating radiator (small circle of coolant circulation); 3 - thermostat; 4 - steam outlet fitting; 5 - branch pipe of the thermostat housing; 6 - gasket.
Electromagnetic clutch for shutdown of the fan is shown in Fig. 15.
The clutch is turned on and off by the relay on commands from the engine management system controller.
After starting the engine at a low coolant temperature, the rotation of the pulley to the driven disk and the associated fan hub 2 with the bearing is not transmitted, because the end of the pulley and the driven disc are separated by a gap A. The required gap is provided by adjusting the position of the three tabs of the driven disc stop. In the extreme right position, the driven disc is held by three leaf springs.
After the engine warms up and the coolant reaches a temperature of + 89 ° C, the controller sends a command to the relay to turn on the electromagnetic clutch. The relay closes the contacts and supplies current through the connector to the coil winding. The resulting magnetic flux is closed through the driven disk and attracts it to the end of the pulley, overcoming the resistance of three leaf springs. The hub of the fan 2, like the fan itself, begins to rotate at the same time as the pulley.
When the temperature drops below 81 ° C, the controller turns off the relay, which breaks the power circuit of the coil winding. Under the action of three leaf springs, the driven disk moves away from the end of the pulley by the amount of clearance A. The fan hub together with the fan stops rotating. When the coolant temperature rises above 89 ° C, the process is repeated.
Care of the clutch consists in checking the clearance A, and, if necessary, adjusting it using a flat feeler gauge 0.4 mm thick by bending the three stops of the driven disc.
The coupling must be periodically cleaned of dust and dirt. Additional lubrication of the coupling during operation is not required.
Almost all car enthusiasts know that a car has an engine cooling system. UAZ Loaf or 452 is equipped with a simple design of the power unit, and therefore the rest of the systems have simple design features.
The purpose of the cooling system
The UAZ Loaf engine cooling system is designed to cool the engine during operation. So, the cooling elements remove the generated heat from the cylinder block and the head with the help of coolant and cool it in the radiator.
During operation, the power unit of the car heats up to exorbitant temperatures and if there is no cooling, then the engine parts will simply overheat and deform. Although, such situations also occur in the presence of a coolant system, in the case when it is not in working order or one of the important elements is out of order.
The operating temperature of the engine on the UAZ Loaf is 80-100 degrees Celsius. It is in this interval that the thermostat opens to a large cooling circle.
Since on this car an electric fan is not provided, but there is a forced cooling system, then additional cooling of the radiator is constantly on.
The power unit can overheat if one of the cooling elements is out of order. First, there will be an easy stage, in which the motor will simply boil. But, there can be serious consequences, such as deflection and deformation of the cylinder head. At this stage, the situation can be corrected by ordinary grinding the surface of the block head.
In the middle stage, engine elements may deform. These include valve train... Subsequently, the block head will need overhaul, and this will come out in a considerable penny to the owner vehicle.
The hard stage is when it collapses piston group from strong exposure to heat. But, and this is not the worst thing that can happen, because if the coolant gets into the cylinders of the car, then the engine will overtake a water hammer, in which the overhaul does not always save.
Coolant system diagram
The diagram of the UAZ engine cooling system is quite simple, it is of a closed type with forced circulation of the coolant. "Cooling" circulates in a circle from the radiator, passing the water pump and thermostat into the cooling jacket, and then returns.
Consider the cooling scheme of the power unit on UAZs, and in particular on the engine marked 452:
Cooling system element
The main elements of the cooling system of the power unit of the UAZ Bukhanka 452 engine are well-known parts: a radiator, a fan, a water pump, a thermostat, pipes, a water jacket and a temperature sensor. Also, a heater is part of the design.
So, let's consider what the main elements of engine cooling are, their structure and operation, as well as repair and revision.
Radiator and fan
UAZ vehicles can be equipped with 3-row copper or aluminum radiators, which provide maximum cooling of the liquid. Since the operation of the elements is quite long, the cooling process of the power unit is not always the same as it should be.
In this case, this is due to clogging of the channels inside the element. Often, even ordinary cleaning does not help, and increased wear makes cracks in the tubes, which are actively soldered by the owners, not wanting to buy new parts. The main purpose of the radiator is to cool the fluid that circulates from the engine using the wind flow.
The fan of the cooling system on the Loaf is forced, fixed on the pulley and runs constantly until crankshaft spinning. Many motorists upgrade this system and install electric fans, which are often turned on by the driver himself according to the temperature readings on the dashboard.
Water pump
The pump for the UAZ is a mechanical drive. The main purpose of the element is to continuously circulate coolant through the system. So, the water pump provides a flow of liquid into the radiator for cooling and vice versa. A malfunction of this element can lead to the loss of "cooling" and overheating of the engine.
Thermostat
The main structural element is a thermostat. It circulates fluid and serves as a switch between the small and large circle in the system. To warm up the vehicle, the element is kept closed. When it reaches 80 degrees Celsius, it starts to open, thereby circulating fluid through the radiator.
The main malfunction can be considered a jamming of the element, which can lead to overheating of the motor, since, as practice shows, the thermostat wedges on a small circle, and, accordingly, there will be no additional cooling and fluid flow through the radiator.
Connections and water jacket
Nozzles are a means of transporting fluid through the system from the engine and its elements to the radiator and vice versa. Failure of these elements leads to the loss of "cooling", which, in turn, lowers the coolant level in the system, and this is a direct path to overheating.
Water jacket - design features of the head and cylinder block. It is through these holes that the coolant flows, which takes away heat for cooling. With a long service life, especially in water, corrosion can form inside the walls, which will lead to leaks and loss of fluid.
temperature sensor
The temperature sensor on the Loaf is not the same as most motorists are used to seeing. This is an old-style element that does not include an electric fan, since a forced system is installed here, but simply outputs to dashboard temperature indicators.
Output
As you can see, the diagram of the UAZ Bukhanka (452) engine cooling system is quite simple. It can be easily repaired, and broken parts can be replaced without much difficulty. This unit consists of components - radiator, fan, water pump, thermostat, pipes, water jacket and temperature sensor.
The coolant sensor is fundamentally different from modern ones, since it does not turn on the fan, but simply shows the temperature of the "cooling".
UAZ "Loaf" is four-wheel drive vehicle off-road. This model in production since 1957. This machine is used not only for its intended purpose, because after all, it is a special technique, but it is also used by lovers of fishing and hunting.
The main advantage of this car is its versatility and great cross-country ability. The salon can accommodate 10 passengers, and if necessary, it can be transformed as you like. The heart of the car is the ZMZ-402 and ZMZ-409 engines. Since the car is special, many are interested in how the cooling system of the UAZ "Loaf" is arranged.
General device
Closed-type liquid cooling is used in these passenger-and-freight cars of the wagon layout. The coolant circulates in the system forcibly under the influence of a centrifugal pump. The manufacturer recommends using the domestic "Tosol" as coolants. However, in emergency cases you can pour ordinary water into the cooling system of the UAZ "Loafs". The volume, including not only the circuits of the cooling system, but also the heater, on most models ranges from 13.2 to 15.3 liters.
Cooling system diagram for ZMZ-402
It's simple enough. This power unit is cooled by fluid that flows through two circuits.
The system is built according to the ring scheme and consists of several main components. The liquid moves from the radiator through the pipes to the thermostat, then passes through the engine cooling jacket. Then, by means of a water pump, it enters the radiator again. In addition, the cooling system of the UAZ "Loaf" with a 402 engine includes an electric fan, a temperature sensor, and heaters. Let's consider each element separately.
Thermostat
It is the most delicate component in the system. It most often fails - modern spare parts are not very high quality. The thermostat function is to control the coolant flow through the engine. The ZMZ-402 unit, like many others, has two coolant circulation circles - large and, accordingly, small.
When the driver starts the engine and it warms up a little, the liquid in the cooling system of the UAZ “Loaf” circulates only in a small circle. This allows the engine to warm up faster. When the temperature reaches about 70 degrees, the thermostat will work, and coolant will flow through the cooling radiator in a large circle. Operating temperatures for the 402 engine are indicators in the range from 82 to 90 degrees. If the engine does not warm up to these temperatures, then this indicates that the thermostat is faulty. Often, due to wear, it will jam and will not open.
water pump
This is very important element... Due to it, the liquid can circulate directly throughout the entire system. In this engine, the antifreeze circulates constantly forcibly. The pump consists of several elements - if necessary, it can be easily disassembled. The pump is located in the front of the cylinder block, and it is driven by a belt drive.
Radiator and cooling fan
When the liquid in the cooling system of the UAZ "Loaf" passes through the engine, it will be warmed up. It must cool down to cool. For this, a radiator is used. On these cars, the manufacturer installs mainly copper 3-row radiators. However, the owners prefer to install aluminum solutions instead. As the reviews note, with them the engine is cooled much more efficiently.
The radiator in the system acts as a cooler. It is cooled by the oncoming air flow while driving. When the vehicle is stationary or moving at low speed, the air flow is weak and cannot sufficiently blow off the radiator. Then the fan comes in. In this car, it is a forced type. The element rotates when the engine is running, regardless of the coolant temperature. Thus, it is very difficult to overheat the engine.
Cooling jacket and pipes
To connect various units of the cooling system of the 402nd engine of the UAZ "Loaf", branch pipes are used. These are rubber products in the form of tubes. The elements are reliable enough, but if they are used long enough, they wear out - they age. Then the coolant can leak and its level drops. As a result, the motor overheats.
The cooling jacket is a necessary part, without which the motor simply will not cool down. The shirt runs through the entire cylinder block. It acts as a heat sink. The coolant is then led out to the radiator.
ZMZ-409 engine
This motor is distinguished by a different valve cover, an improved timing mechanism, and a different cylinder head gasket. The volume of the power unit also increased, which immediately entailed the modernization of the cooling system ZMZ-409 UAZ "Bukhanki".
The device of the cooling system is typical for an internal combustion engine of this design, which have ever been manufactured at the Zavolzhsky plant. The engine is equipped with a liquid closed forced system. There is also a radiator, a jacket in the cylinder block and in the cylinder head, a pump, an expansion tank, temperature sensors, an electric fan, a heater radiator and other elements. Note that the principle of operation of the cooling system 409 UAZ "Loafs" is simple and similar injection motors... Here, the coolant also moves in a large circle and in a small one.
Radiator and fan
With these elements, the engine does not overheat above its operating temperature. On the first models with this power unit there was a three-row copper radiator, but after not very successful tests, they began to install aluminum ones. As for the fan, here it is already electric. The element is controlled by the ECU and the temperature data is read directly from the cooling jacket.
Thermostat
The function of this element is the same here. It is necessary to open or close the path of the liquid from a small to a large circle, or vice versa.
This thermostat on the motor opens at a temperature of 75 degrees. This is one of the important parts of the engine. If the thermostat is faulty, the engine will overheat.
water pump
It makes the coolant circulate throughout the system. This is an ordinary unremarkable water pump. Sometimes bearings jam in it, and then antifreeze leaks occur.
Heater
It is also one of the integral parts of the cooling system of the UAZ “Bukhanka” with the 409th engine. The heater consists of inlet and outlet pipes, as well as a radiator and an electric fan. The stove is actively used in winter, which has an even better effect on engine cooling.
Expansion tank
Gases and vapors generated in the system during its operation are squeezed into this container. It is also the coolant level. The tank cap is designed in such a way that excess air is forced out through it.
Temperature sensor
This element measures the temperature and gives the measurement results to the ECU. Further, the control unit regulates temperature regime... You can find this sensor on the thermostat.
Disadvantages of the system
V standard system there is only one plus - it works. The owners cannot say that it is flawlessly reliable. It's all about the quality of spare parts. But all the other advantages that this system has can be safely attributed to the disadvantages. On the 402 motor, the fan is too low-speed - the number of its revolutions is strictly limited by the pump. To have enough of them, you need a large radiator. In winter, you have to close this radiator so that the motor does not freeze. There are also problems with the operation of the heater. Without additional artificial pumping of antifreeze, you can not wait for heat.
All these problems can be solved by modernizing the cooling system 402 of the UAZ "Loaf" engine (replacing the radiator with a multi-section one, installing a second stove, and so on). Many owners are improving it to increase work efficiency.
So, we have found out how the cooling system of the UAZ "Loaf" with the engine of 409 and 402 models is arranged. The device is very simple, but the reliability of the system leaves much to be desired, as the owners say.
The cooling system of the UMZ-421 engine is liquid, closed, with forced circulation of liquid and an expansion tank, with fluid supply to the cylinder block. For normal engine operation, the coolant temperature must be maintained within plus 80-90 degrees. Short-term operation of the engine at a coolant temperature of 105 degrees is permissible.
Such a mode can occur in the hot season when the car is moving with full load on long climbs or in urban driving conditions with frequent accelerations and stops. Maintaining normal coolant temperature is carried out using a two-valve thermostat.
The cooling system of the UMZ-421 engine includes a water pump, a thermostat, water jackets in the cylinder block and head, a radiator, an expansion tank, a fan, connecting pipes, and a body heating radiator.
Cooling system water pump UMZ-421.
The cooling system pump of the UMZ-421 engine is of a centrifugal type, driven by a V-belt from the crankshaft pulley. Belt dimensions 10.7x8 mm, belt length on UAZ cars - 1030 mm, on GAZelle cars - 1018 mm. The pump body and cover are made of aluminum alloy. The pump design uses a special double-row ball bearing 5HR17124E.P6Q6 / L19 or 6-5HR17124EC30, with a double-sided seal, with a roller instead of inner rings.
Since 1999, an armlen impeller of the PP SV-30 brand with straight radial blades, designation 421.1307032-04, has been used on water pumps, instead of the previously used impeller with backward curved blades, designation 4022.1307032. As a result of the transition to a new impeller, the performance and supply pressure of the water pump were significantly increased, which made it possible to ensure reliable operation of the engine cooling system, as well as to increase the efficiency of the interior heating system.
Thermostat type TS-107.
Two-valve, with a solid filler, is located in the outlet pipe of the cylinder head and is connected by hoses to the water pump and radiator. The main valve of the thermostat begins to open at a coolant temperature of 78-82 degrees, fully open at a temperature of 94 degrees.
When the main valve is closed, the liquid in the engine cooling system circulates, bypassing the radiator, through the open additional thermostat valve inside the engine cooling jacket. When the main valve is fully open, the auxiliary valve is closed, all the liquid passes through the cooling radiator.
The thermostat automatically maintains the required temperature of the coolant in the engine, shutting off the circulation of fluid through the radiator. In cold weather, especially at low engine loads, almost all of the heat is removed as a result of the cold air blowing over the engine, and the coolant does not circulate through the radiator.
The thermostat must not be removed from the cooling system, since in the cold season, the engine without a thermostat takes a long time to warm up and runs at a low coolant temperature. As a result, its wear accelerates, fuel consumption increases, there is an abundant deposition of resinous substances in the engine, and the normal air temperature in the car interior is not ensured.
In the warm season, in the absence of a thermostat, most of the coolant will circulate in a small circle through the engine cooling jacket, bypassing the radiator. This will result in overheating of the engine.
Expansion tank of the cooling system.
On UAZ cars, the expansion tank of the UMZ-421 engine cooling system is directly connected to the atmosphere. The regulation of the exchange of fluid between the tank and the closed volume of the system is regulated by two valves: inlet and outlet, located in the radiator plug. The outlet valve opens at an overpressure of 0.45-0.60 kgf / cm2, and the inlet valve opens at a vacuum of 0.01-0.1 kgf / cm2.
Circulation of coolant in a small circle.
When the engine warms up, when the coolant temperature is below 80 degrees, a small circle of coolant circulation operates. The upper thermostat valve is closed, the lower valve is open.
The coolant is pumped into the cooling jacket of the cylinder block by a water pump, from where, through the holes in the upper plate of the block and the lower plane of the cylinder head, the liquid enters the cooling jacket of the head, then into the thermostat housing and through the lower thermostat valve and the branch pipe to the inlet of the water pump. In this case, the radiator is disconnected from the main flow of the coolant.
For a more effective operation of the interior heating system when circulating liquid in a small circle, this situation can be maintained for a long time at low negative ambient temperatures; there is a throttle hole with a diameter of 9 mm in the liquid outlet channel through the lower thermostat valve. This throttling leads to an increase in the pressure drop at the inlet and outlet of the heating radiator and more intensive circulation of liquid through this radiator.
In addition, throttling of the valve at the liquid outlet through the lower thermostat valve reduces the likelihood of emergency engine overheating in the absence of a thermostat, since the shunting effect of the small circle of liquid circulation is significantly weakened, therefore, a significant part of the liquid will go through the cooling radiator.
In addition, to maintain a normal operating temperature of the coolant in the cold season, UAZ cars have louvers in front of the radiator, with which you can adjust the amount of air passing through the radiator.
Circulation of coolant in a large circle.
When the temperature of the liquid rises to 80 degrees or more, the upper thermostat valve opens, and the lower valve closes. The coolant circulates in a large circle. For proper operation, the cooling system must be completely filled with liquid.
When the engine warms up, the volume of liquid increases, its excess is pushed out due to the increase in pressure from the closed circulation volume into the expansion tank. When the temperature of the liquid drops, for example, after the engine stops working, the liquid from the expansion tank is returned to the closed volume under the action of the resulting vacuum.
The engine of the first issues is installed on my car, and this was the problem with the cooling. So the outlet diameter (from the thermostat housing) of the pipes of the large and small cooling circles was practically the same. I understand that when the engine is running, the thermostat is rarely in extreme positions, from the antifreeze it simultaneously runs along small and large cooling circles to a greater or lesser extent. Since a small circle of cooling has less resistance (compared to a large one) of the passing liquid, then its main part rushed there. Hence the increased engine temperature.
This effect was eliminated by slowing down the small cooling circle. For this, a washer was made with a thickness of 5-8 mm, an outer diameter of the size of a rubber tube plus 2 mm, a hole diameter of 12 mm. I installed it in the branch pipe of a small cooling circle and fixed it with a clamp for reliability. After this operation, the engine temperature stabilized at about 80 * C (thermostat at 80 * C). On later releases of these engines, this problem was solved at the factory level; the diameter of the hole for the passage of the antifreeze into the outlet pipe of the small circle is of the order of 10-12 mm.
The next stage of modernization concerned the fan itself.
The installed plastic impeller gave way to an electric fan. Such a change was caused primarily by the increased depth of the fords to be overcome (well, this is how it began to turn out on the hunt - the further into the forest, the deeper :).
As I already reported in the elevator report, the radiator was also lifted, so that it stood exactly in the body opening intended for it (otherwise the elevator operators had complaints about the somewhat deteriorated cooling).
So the blinds disappeared from the radiator (I don’t complain about the thermostat) and the oil cooler (I don’t use it because of good oil).
The radiator itself migrated to the frame cross member, to which its native brackets are welded (i.e., it moved forward and upward). Thus, it was again in its place relative to the body. At the same time, it was necessary to make elongated radiator thrust-stops from a steel bar. I drilled the cross member of the frame with a 12mm drill (against the native brackets) and picked up the bolts for fastening the corresponding length.
The operation of moving the radiator forward made it possible to implant an electric fan from a GAZ-3110 with a 406th engine, it is almost the same size as our regular one.
It is mounted using its own bracket, but with ears digested in place under our UAZ radiator. When installing the fan on the radiator, I used rubber-metal bushings from the VAZ-2108 timing drive cover as spacers, 2 of them were installed. under each support (supports - ears in total 6). After assembly, this whole structure is covered with a native radiator diffuser.
Now, this design had to lengthen the radiator pipes, the lower one was picked up in the store according to the template, and the upper one was native, it was simply cut and a tube with a bimetallic fan switch (additional, about it below) was inserted into the cut, which by itself lengthened the upper pipe.
For difficult driving conditions, there is an additional electric fan, it is installed in front of the radiator (it is from the GAZ-3110), it turns on (or rather, it will turn on) a little later than the main (large) fan. It's in the machine. According to the scheme, the following modes are provided:
- Enabled automatically.
- Disabled forcibly.
- It is included forcibly.
These are modes for both fans, the switches are separate.
The main fan is controlled in the vending machine by an electronic unit connected to the thermistor of the engine temperature gauge, the additional fan is switched on from the bimetallic sensor in the upper branch pipe.
This system I have been operating with a radiator from 3160 since August 2003. When driving around the city (including traffic jams), one main fan handles everywhere, there is no need to talk about the highway, it does not work there at all. An additional one is required when driving on a downgrade and towing off-road, etc. The first cool days (about 0 * C) showed that the UAZ does not need a fan even in city traffic, with rare exceptions (such as standing in a traffic jam).
