Coolant overheat alarm

Most cars are equipped with a temperature sensor that measures working temperature engine. If the overheating alarm comes on while driving (or the temperature indicator arrow goes into the red danger zone), this means that the coolant temperature is between 120 ° C and 126 ° C. This temperature is still below the boiling point of the coolant (assuming that the cooling system and radiator pressure cap are in good working order). If the coolant overheat signal comes on, do the following:

Step 1. Switch off the interior air conditioner and switch on the interior heater. This will help remove excess heat from the engine faster. Install the fan on maximum speed rotation.

Step 2. If possible, turn off the engine and let it cool down (this may take more than an hour).

Step 3. Never try to remove the radiator sealed plug until the engine has cooled down.

Step 4. If the overheating alarm is illuminated, you must not continue driving or the engine could be seriously damaged.

Step 5. If the engine does not burn with heat and is clearly not overheated, then it is possible that the problem is related to a malfunction of the temperature sensor or temperature indicator. Then you can continue driving, but for reassurance, you need to stop from time to time to check if there are signs of engine overheating and if there are traces of coolant leakage.

COMMON CAUSES OF ENGINE OVERHEATING

Low level coolant.

Clogged, dirty, or blocked radiator.

Faulty fan clutch or faulty electric fan.

Incorrectly set ignition timing.

Low oil level in the engine lubrication system.

Broken fan drive belt.

Defective radiator seal.

Brakes seized.

Freezing of the coolant (in frosty weather).

Faulty thermostat.

Defective cooling water pump
(slippage of the impeller on inner shaft pump).

Experience exchange

The owner complained that the engine of his car was overheating, but this only happens when he is driving on the freeway at high speed. The car was equipped with an engine that worked flawlessly when driving in an urban cycle.

The mechanic flushed the cooling system and replaced the radiator sealed plug and water pump, believing that the cause of overheating was a decrease in coolant flow in the cooling system. In the course of further verification, it was revealed that when the engine was cranked with the starter with the spark plugs unscrewed, coolant was sprayed out of one of the cylinders. The problem was resolved after the cylinder head gasket was replaced. Obviously, the leakage caused by a defective gasket was not so great as to cause a malfunction of the engine - as long as the speed and load on the engine did not increase so much that the increase in coolant leakage and heat generation caused by them did not lead to a rapid increase temperature.

The mechanic also replaced the oxygen (0 2) sensor, because the composition of the coolant contains organosilicon compounds and silicates, which, once on this sensor, usually poison it. Sensor degradation may have contributed to this problem.

Rice. 7.42. In the mid-1980s, many manufacturers began using V-ribbed belts (ribbed V-ribbed belts instead of transverse teeth). Older water pumps will fit the engine, but they may turn out to rotate in the opposite direction of what they should. This can lead to overheating of the motor after replacing the pump. If you install a fan of the wrong type, then the angle of attack of its blades will not correspond to the required one to create the necessary air flow through the radiator.

For proper operation of the cooling system, the condition and correct installation drive belt... The tension of the drive belt has a decisive influence not only on the operation of the water pump, but also on the alternator, air conditioning compressor and other belt-driven units. When replacing the belt or adjusting its tension, it is imperative that the belt tension is measured using a belt tension meter in order to check that it exactly matches the required one.

He laid the foundation for a whole family of cars. Some of them are still in production today. This lineup is inherent high reliability and the relative ease of execution, which is one of the main reasons for the high popularity of the car. At the same time, the conditionally long-term operation revealed a number of significant shortcomings. One of them is the cooling system.

It works great on a relatively new car, however, as soon as the service life exceeds 10 years, it malfunctions. Ultimately, they manifest themselves in the same way. The arrow of the device indicating the temperature invariably creeps up. There may be several reasons why the VAZ 2110 engine heats up, and this problem requires detailed consideration.

Vehicle cooling system

The cooling system is made according to the classic scheme. The circulation of the coolant is carried out in large and small circles. Its transition from one circle to another is carried out automatically using a thermostat. Cooling of antifreeze occurs in a radiator, which is made of aluminum for better heat transfer.

To prevent engine overheating during long-term operation in low gears, a fan is provided in the car, which turns on automatically when the temperature reaches a certain value. The main causes of a VAZ 2110 car malfunction:

• breakdown of the thermostat;
• the fan does not work;
• airlock;
• low coolant level;
• dirty engine surface.

Any of these reasons may cause the engine to get very hot. As a result, the car will lose a significant part of its power.

Faulty thermostat and fan

A symptom of a malfunctioning thermostat is a sudden rise in temperature for no apparent reason. That is, the car engine worked in normal mode, there was no long standing in traffic jams and movement in first gear, and the arrow of the device is close to the critical mark. Why is this happening? The fact is that, as a rule, the thermostat wedges in the closed position.

In this case, the liquid continues to circulate bypassing the radiator, which is not enough to cool the engine. Determining whether the thermostat is really to blame is very simple. It is necessary to warm up the engine to a temperature of 90 ° C. Now you should evaluate the temperature of the pipe that goes to the radiator. If it is cold, the thermostat must be replaced.

Unlike the previous case, engine overheating is preceded by prolonged operation in low gears. In this mode, the VAZ 2110 radiator does not have sufficient airflow, and when the temperature reaches 95 ° C, a sensor is triggered, which turns on the fan. If this does not happen, overheating of the engine is inevitable. Such damage is complicated by the fact that malfunctions, other than the fan itself, can occur in its power supply circuit.

As a special case, a blown fuse should be mentioned. In addition, the sensor itself can fail. This is why it is so important to correctly identify the faulty node. This can be done as follows. It is necessary to close the sensor contacts, it is installed on the radiator. Be careful when performing this operation. In this case, the engine must be turned off and the ignition turned on.

If, when the contacts are closed, the fan motor starts to rotate, the sensor is faulty. If not, then the reason may be in the fuse, and you need to check it. If it is working properly, further repairs require skills and a special device, so it is better to contact a specialist.

Each car owner was faced with the fact that the 16-valve VAZ-2112 engine began to warm up. If you look at the indicator dashboard, then the arrow tends to the red zone, and in expansion tank the liquid boils - this means that there is a malfunction in the cooling system.

The arrow of the temperature indicator has entered the red zone, which means that the engine is in a state of overheating.

Many motorists remember the reasons for the effect on old Zhiguli cars. On 16-valve engines, the reasons for this effect are almost the same. Consider what reasons can serve as the main power unit begins to bask in excess:

• Clogged system.
• Thermostat jammed.
• Damage to the pump. Replace your pump. ...
• Radiator.
• Cooling sensor malfunction.
• Cooling fan failure (see ")".

All these problems can cause engine overheating.

Elimination methods

To eliminate the causes of engine heating, it is necessary to establish the epicenter of the effect. To do this, it is worth checking each node sequentially. After identifying the problem, it is worth finding the exact cause and fixing it. So, consider the sequence of actions.

Engine cooling system diagram

Radiator and pipes

One of the reasons for engine overheating can be the clogging of the radiator and pipes, which affects the circulation of fluid in the system, and can also lead to cracks in the pipes and breakdown of the radiator, which will lead to the leakage of coolant.

With an insufficient amount of coolant in the system, the power unit will heat up faster and cool down for a long time, and the cooling fan will work almost continuously.

Radiator and cooling system pipes

The method for solving the problem is quite simple - dismantling the radiator from the system and cleaning it both outside and inside.

The second step will be to inspect the pipes for leaks and replace worn out products. As practice shows, many motorists install Kit-kits (tuning versions) of the radiator and pipes to extend the service life of the cooling system.

Pump (water pump)

One of the main causes of overheating is that it appears water pump play ... It is quite easy to determine this malfunction, because a corresponding howl appears in the pump area. Also, a sign of a malfunction may be that liquid will flow from the pump shaft. The malfunction is eliminated quite easily - by replacing the water pump.

Engine-mounted water pump

Thermostat

The thermostat is the first place to look for a malfunction.

So, for jamming of the thermostat on a small circle, the engine heats up more often usually, even when traveling on a highway where there is enough oncoming air flow for the system to have time to cool itself.

Thermostat removed from the motor

There is one caveat when the thermostat should not be changed - if it fails in winter. Then, additional cooling is provided by sub-zero temperatures. Of course, if the thermostat fails in the summer, then to prevent overheating of the motor, it must be replaced as soon as possible.

Cooling sensor

The cooling temperature sensor is a harmless breakdown, which can lead to the fact that the indicator on the instrument panel will show incorrect data, so the driver will not even know that the engine has overheated until it boils on the way.

Usually, this malfunction is accompanied by many accompanying factors, so it is quite difficult to miss it. There is only one solution to the problem - replacing the cooling system sensor and resetting errors that occurred in the ECU.

Cooling sensor

Fan

The last reason for overheating, especially in the summer, is the cooling fan.

The fan under the hood is indicated by an arrow

So, a breakdown of this unit can lead to the fact that the engine overheats, as well.

In this case, the consequences can be very diverse, well, what needs to be checked for serviceability of the fan, as well as the sensor for turning it on - that's for sure. This part fails quite rarely, and therefore an elementary fuse or wiring malfunction, which can be easily eliminated, can become the cause of failure.

Consequences of untimely elimination of defects

Not all drivers are aware of the consequences of overheating the engine and continue to drive with a constantly running fan or frequent overheating.

So, the consequences of strong engine heating are divided into 3 stages, which should be considered separately.

Weak overheating

If the engine overheats for up to 10 minutes, the consequences may be negligible. So, cracks will appear in the pipes of the cooling system, the valve seals will melt and camshaft... Also, the valves will burn out, and oil will enter the combustion chambers, which will be marked by the release of black smoke from the exhaust system.

Consequences of weak overheating, namely burnout of valves

Significant overheating

With significant overheating, deformation occurs, or rather deflection of the cylinder head. To eliminate these consequences, you will have to dismantle the cylinder head and give it to the surface groove. Thus, it turns out that the head of the block is subject to overhaul.

Severe overheating

With severe overheating, the walls of the cylinder block are deformed and burned out, while the piston group melts, the connecting rods are deformed, or even the crankshaft breaks. Thus, the engine cannot be repaired, since the walls of the power unit usually collapse, and their restoration is impossible.

conclusions

Causes of heating and overheating 16 valve engine methods of elimination are established and considered. So, untimely repair of this unit can lead to the fact that the engine will finally fail and will need to be replaced. Therefore, if the first signs appear that the cooling system has failed, it is necessary to find and eliminate the cause, since the replacement will come out, much more expensive.

At the first signs of overheating, if the arrow of the temperature gauge has moved into the red zone, but steam does not escape from under the hood, turn on the maximum heating mode of the passenger compartment (see "Automatic heater control system"). This is necessary in order to lower the temperature of the coolant in the engine cooling system.

Turn on alarm, depress the clutch pedal and, using the vehicle's inertia, try to carefully move to the edge of the carriageway and stop as far to the right as possible at the side of the road, and if possible - outside the carriageway. Run the engine for a couple of minutes at normal idle speed with the full power heater.

A WARNING
Do not stop the engine immediately! The only condition is to maintain the tightness of the cooling system. If a hose bursts or comes off, or if there is a leak other than fluid escaping from the expansion tank plug, the engine will have to be stopped immediately!

After stopping the overheated engine, local overheating of the coolant begins at the points of contact with the most heat-stressed engine parts and the formation of vapor locks. This phenomenon is called heatstroke.

1. Stop the engine.

2. Open the hood and inspect engine compartment... Determine where the steam is coming from. When inspecting the engine, pay attention to the presence of coolant in the expansion tank, to the intact rubber hoses, radiator, thermostat.

A WARNING
Never open the expansion tank cap directly. The liquid in the cooling system is under pressure, when the plug is opened, the pressure will drop sharply, the liquid will boil and its splashes can scald you. If you want to open the expansion tank cap on a hot engine, first put a thick thick cloth on top and only then carefully unscrew the cap.

USEFUL TIPS
An important role in ensuring optimal temperature conditions is played by the expansion tank plug valve. It maintains an overpressure in the system of at least 0.1 MPa (1.1 kgf / cm2). In this case, the boiling point of water rises to 120 ° С, and antifreeze - up to 130 ° С. Unfortunately, when the valve is jammed in the closed position during overheating, a significant excess of excess pressure occurs - more than 0.2 MPa (2 kgf / cm2), which can lead to a rupture of the expansion tank or the breakdown of one of the hoses.

3. Look under the dashboard from the front passenger side and find out if there is a leak or traces of coolant leaking from the heater radiator underneath.

If coolant leaks are found, the burst hose can be temporarily repaired with adhesive tape.

HELPFUL ADVICE
Reinforced (usually silver-colored) adhesive tape, which can be obtained from car dealerships, is especially suitable for this purpose.

The leakage of a radiator, thermostat or heater is rather difficult to eliminate on the spot, therefore, in such a situation, it is necessary to add water to the cooling system and carefully monitor the temperature indicator while driving, periodically restoring the level in the cooling system.

WARNINGS
Long-term use of water instead of antifreeze leads to the formation of scale in the engine cooling system, deterioration of its cooling and, as a consequence, a reduction in the resource.
Never add cold water to an overheated engine. The engine must cool down with the hood open for at least 30 minutes.

4. The engine may overheat in the event of a failure of the thermostat, which regulates the flow of fluid in the cooling system through the radiator or past it (to accelerate the warm-up of a cold engine). To check the thermostat, on a warm engine, feel the temperature of the hose connecting the thermostat housing to the radiator. If the hose is cold, the thermostat is faulty, there is no circulation through the radiator.

5. Very often the cause of overheating of the engine, the cooling system of which is equipped with an electric fan, is the failure of the fan. Start the engine, watch the temperature and pay attention to whether the cooling fan turns on when the engine overheats.

6. If the fan does not turn on, the fuse may be blown, the ON relay is faulty, the motor is blown, or the wiring is faulty.

7. Check the integrity of the electrical wiring, the reliability of the connection of the electrical connectors.

8. If the wiring is OK, check the fuse and replace if defective.

9. If the fuse is good, try replacing the fan relay.

11. If the electric motor starts to work, the wiring is faulty; if not, the wiring or the actual motor is also faulty. The relay and the electric motor are not repairable, replace them as an assembly (see Section 9 "Electrical equipment").

NOTE
It is allowed to drive to the place of repair with an electric motor connected directly to the battery. On arrival, do not forget to disconnect the electric motor from the battery, otherwise it will lead to battery discharge.

Daily checks and troubleshooting
Car operation in winter
A trip to the service station
Operation and maintenance manual
Precautions and safety rules when working on a car
Basic tools, measuring instruments and methods of working with them
Engine and its systems
Transmission
Chassis
Steering
Brake system
Body
Interior ventilation and heating system
Vehicle electrical equipment
Fault codes
Wiring diagrams

Actions in emergency situations VAZ / Bogdan 2110/2111 / 2112. Engine overheating VAZ / Bogdan 2110/2111/2112

2. Engine overheating

As a rule, under normal vehicle operating conditions, the pointer of the coolant temperature gauge is constantly in the middle zone of the scale. The engine temperature may increase when the vehicle is driven uphill for a long time, especially in hot weather. If the arrow of the coolant temperature gauge is in the critical zone, then it is necessary to find out the cause of the engine overheating.

ATTENTION
Steam and splashes of boiling coolant escaping under pressure from the radiator cap of an overheated engine can cause severe burns. Do not raise the hood if steam is coming out from under it.
1. Turn on the hazard warning lights and, depressing the clutch pedal, direct the car to the side of the road, then stop at safe place... Place the gear lever in neutral and engage parking brake... Switch off all auxiliary electrical equipment.
2. If the arrow of the temperature gauge is in the critical zone, but steam is not coming out from under the hood, open the air flow control damper completely and set the heater to maximum. Let the engine run for idle within minutes. Observe the behavior of the arrow on the coolant temperature gauge. If the overheating was caused by an increased load on the engine (for example, during a long steep climb on a hot day), then the engine temperature should begin to drop almost immediately. In this case, it is necessary to cool the engine for Idling... After the engine temperature has returned to normal, when the temperature gauge needle returns to the middle zone of the scale, you can continue driving the car.
ATTENTION
If steam does not come out from under the hood, and hot coolant does not flow onto the road, do not stop the engine immediately.
3. If steam comes out from under the hood, or if hot coolant flows onto the road, this is a sign of a cooling system depressurization, for example, due to a burst or jumped hose. Stop the engine immediately. It should be noted that an overheated engine often cannot stop immediately after turning off the ignition, continuing to work due to the so-called pseudo-hot ignition. In order to forcibly stop the engine, it is necessary to smoothly depress the accelerator pedal to the stop or, by engaging any gear with the clutch depressed, press the brake and release the clutch.
4. Wait for the cessation of vapor emissions or fluid leakage, and then open the hood.
5. Check that there are no obvious reasons for the loss of coolant, such as cracks in the walls of the hoses or leaking pipe connections. Since all parts of the engine and cooling system are high fever, be careful not to get burned. If you find a coolant leak, you must repair and seal the cooling system before continuing to drive. A broken hose can be temporarily repaired with duct tape. Damage to the radiator, thermostat or heater is quite difficult to repair on the spot, therefore, in order to get to the nearest service station, it is recommended to add water to the cooling system and, while driving, carefully monitor the temperature gauge, stopping periodically to allow the engine to cool down and restore liquid level in the cooling system.
ATTENTION
Do not add cold water to hot engine as it may damage it. Let the engine cool completely with the hood open for at least half an hour.
Avoid running the engine for a long time using clean water instead of coolant (a mixture of antifreeze and distilled water), as this will lead to the formation of scale in the cooling system, as a result of which its cooling capacity will decrease and the engine life will be reduced.
6. The cause of engine overheating may be a faulty thermostat. To check it, on a still hot engine, carefully check the temperature of the upper and lower radiator hoses by touch. If the lower hose is cold, the thermostat is defective, as a result of which the coolant cannot circulate through the radiator. In this case, let the engine cool down completely, and then continue driving to the nearest service station, carefully monitoring the temperature gauge and stopping periodically to allow the engine to cool down.
7. If the thermostat is normal, and the engine is still warm, you must turn on the ignition and make sure that the radiator fan rotates. Check the serviceability of the sensor for turning on the radiator fan. To do this, disconnect the connector from the sensor installed on the thermostat housing and connect the connector leads together, then turn on the ignition.
8. If the fan does not turn on after the terminals are closed, the cause of the malfunction may be a blown fuse, a broken relay, or a burned out electric motor. Check the condition of the relevant fuse (see section “Fuses” later in this chapter) and, if necessary, replace it with a new one of the correct rating.
9. To check the performance of the fan motor, you must use two additional wires, which must be connected first to the connector of the electric motor, and then directly to the terminals battery observing the polarity. If the electric motor starts working, it is necessary to check the wiring and the relay for turning on the radiator fan using additional equipment.
ATTENTION
The wires must be insulated and securely fastened. Do not allow shorting of wires to each other!
10. If no coolant leaks were found, check the level in the coolant expansion tank.
ATTENTION
The expansion tank cap should never be opened until the engine has cooled down completely. Since the hot fluid is under pressure at this time, it may splash out or steam under pressure escaping from the plug, which can cause serious burns.
11. If the expansion tank is empty, it may be necessary to top up coolant. Wear protective gloves or cover the lid with a large piece of thick cloth. Carefully turn the cover counterclockwise until you feel it stop. When turning the cover, do not press down on it. After the pressure in the cooling system equals atmospheric pressure, turn the cover counterclockwise additionally. Remove the cover.
12.Add coolant. As mentioned above, if there is no recommended brand of coolant, you can add clean water to the radiator. As soon as possible, completely drain the water-diluted coolant from the engine cooling system and replace it with a recommended brand of conditioner.
13. Close the cover tightly. Start the engine and observe the behavior of the arrow on the coolant temperature gauge. If the needle rises to the red zone again, the engine needs repair. Have the vehicle towed to a service station.
14. If temperature regime engine has returned to normal, it is necessary to check the coolant level in the expansion tank. If necessary, add coolant to the tank and bring its level to the “MAX” mark. Then close the cover of the expansion tank tightly.