Why does the engine heat up? Causes of engine overheating

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

With the onset of summer, many car owners have one of the most annoying problems - engine overheating. Moreover, neither the owners of domestic cars, nor the owners of foreign cars are insured from this. In today's article, we will look at why the engine gets very hot and how you can fix this problem.

In what situations does overheating occur most often?

Especially often cars boil in traffic jams. After several dozen starts and stops, the arrow of the temperature gauge can jump to the limit level even for a foreign car. It is clear that at idle the engine heats up more than at normal speeds. It is impossible to allow the engine to boil frequently, as this can lead to serious and costly repairs to the internal combustion engine.

Why is this happening?

So, our engine is often heated. The reasons for this can be very diverse. One of the probable is a malfunction of the water pump impeller. It is this part of the pump that may not ensure the normal circulation of fluid through the system.cooling. When the engine is idling for a long time (for example, it is in a traffic jam), the antifreeze stagnates in the block. As a result, the coolant begins to boil, which causes the engine to heat up. How to fix this problem? There is only one way out - to purchase and install a new water pump.

Pump belt broken

If the water pump belt breaks, the engine's operating temperature will rise rapidly because the coolant has stopped circulating in the system. You can determine this malfunction visually.

In the event that the water pump is stuck, this will be indicated by the characteristic squeal of the belt slipping along the pulley. It is not possible to repair the pump manually. In this situation, it is recommended to look for a tug and go to the nearest auto repair shop.

Bad thermostat

In the heat, this element can also affect the overheating of the motor. If there is a malfunction of the thermostat, the engine starts to heat up longer, and on the road to constantly increase its operating temperature. Therefore, if the engine heats up at speed, most likely the reason is the thermostat. A low-quality part can simply jam. As a result, the semi-open element is not able to provide normal heat exchange and coolant circulation at high speed. The way out of the situation is similar to the first case - the defective element must be replaced. By the way, many owners of domestic cars in the summer simply take out the thermostat and drive without it. On such cars, the engine does not heat up throughout the hot season. Well, withwith the onset of autumn, motorists again install this element in a regular place.

Note that the engine does not always heat up due to the thermostat. Perhaps the reason for this may be the lack of coolant in the system (we will talk about this a little later). Therefore, the thermostat is always tested for performance before replacement.

This can be done without removing it from the engine compartment. When, when the engine is running, the upper pipe (the one that goes to the cooling radiator) is cold or extremely hot (so much so that it is impossible to touch it), respectively, the part does not allow liquid to pass through itself. The replacement of the thermostat itself is carried out only when the engine is cold.

There is another way to diagnose the thermostat. It consists in using a pot of water and a gas stove. When the liquid in the container is about to begin to boil, the thermostat located in it should open within a few seconds.

If this did not happen even when the water boiled, then the device is inoperative. Thermostats cannot be repaired.

Candles and ignition system

The main symptom indicating a malfunction of the candles is the unstable operation of the engine "cold". Sometimes the motor troit, and during acceleration there is a noticeable drop in power. All this is displayed not only on the dynamics, but also on the operating temperature of the engine, which reaches 100 degrees Celsius or more. The reason for this is badcontact in the high-voltage ignition system, which prevents the operation of one of the cylinders. It also happens that the candle itself has exhausted its resource and needs to be replaced. In this case, there will be black soot at its end.

If problems reappear after this repair, the cause may be hidden in the cover of the breaker-distributor (it will have cracks). In extreme cases, the set of wires, the slider or the cover of the distributor changes.

Why does the engine heat up? Coolant leak

If there is a leak of antifreeze in the system, this will certainly lead to overheating of the motor. It is very easy to identify this error. As soon as the temperature arrow approaches the red mark, turn on the stove. If cold air comes out of the nozzles instead of hot, then there is no or insufficient coolant in the system. It is because of this that the diesel engine and gasoline engine are heated by most of our motorists.

It is extremely dangerous to continue driving with a half-empty radiator. In the event of a coolant leak, stop the engine and inspect the engine compartment. Most often, the engine heats up due to leaky pipes. Damaged tubes should be replaced or temporarily wrapped with electrical tape (until the first auto parts store). At the same time, antifreeze is added to the cooling system to the desired level.

Airlock

If the engine is warming up (VAZ or Mercedes - not so important) stably every 1-2 hours, the reason for this may bebecome airing the cooling system. In this case, it is necessary to drive the front of the car downhill (an overpass would be an excellent option), open the reservoir and radiator caps and wait until after 10 minutes the air comes out on its own. This is the most effective way to eliminate air congestion in cars and SUVs.

Fan failure

Fan operation is directly related to its sensor. It is he who gives a signal with a sharp increase in engine temperature. If the fan has stopped working, most likely the problem is hidden in the sensor. The latter must be replaced if it fails. Also, the fan turns on forcibly. To do this, just remove the terminal that goes to the sensor wire.

Clogged radiator

One of the most likely reasons why the engine is heating up is the presence of various deposits inside the system. Dirt, along with distilled water, can get on the pipes, but most often it “lurks” in the radiator honeycombs.

In order to eliminate this malfunction, the system must either be purged or cleaned. The latter method is more effective, since it removes up to 99 percent of the deposits that have accumulated on the walls of the radiator for years when using abrasive chemistry.

DIY internal cleaning

If instead of antifreeze you use distilled water, you should regularly clean the inside of the system from adhering scale. This is done with the help of special tools that can be bought at any hardware store. Are calledthey are simply: "descaling agent". You can also find them in automotive stores or do it yourself. In the latter case, we need caustic soda and a few liters of warm (preferably hot) water. This mixture is diluted in the following proportions: for 1 liter of liquid - 25 grams of soda.

The resulting substance is poured into the radiator for 15-20 minutes. At this time, you need to let the engine idle, so that the product collects scale from the entire cooling system. It is important not to overexpose the mixture inside the system. After 20 minutes of being in the SOD, aggressive "chemistry" will begin to corrode not only scale, but also the thin walls of the radiator itself. As a rule, after washing, this mixture acquires a rusty tint. This indicates that there was a large amount of dirt and deposits inside the engine cooling system. After use, it is not recommended to pour such a liquid into the garden - move it to any container and pour it into the area as far as possible from residential buildings. And one more thing: when working with such products, you should use rubber gloves and try not to inhale the vapors of this mixture. They are very dangerous for the human body.

External cleaning

It happens that after cleaning the car, the engine heats up again. GAZelles and other domestic-made cars in this case should be subjected to purging of the radiator walls. The essence of this method is to remove various deposits that have accumulated on the outer part of the element. It could bemidges, poplar fluff and other debris that prevented the normal heat exchange of the radiator with the external environment. You can blow or wash the walls of the part manually, using a vacuum cleaner or hoses. But it is best that the cleaning of garbage is done under great pressure. At the same time, remember that the radiator cells are very fragile and thin, so the purge is carried out from its back side. Those small parts that could not be cleaned with a hose or vacuum cleaner are cleaned manually with a fine sewing needle, nail and other small tools.

As practice shows, after the external and internal cleaning of the system, most motorists no longer ask questions about why the engine is heating up and how to prevent antifreeze from boiling. Moreover, this method is effective not only on domestic, but also on imported cars.

How to behave if the engine heats up quickly?

When you notice that the temperature needle is gradually entering the red scale, immediately turn on the stove at maximum power and pull over to the side of the road.

If after 1-2 minutes the arrow has not fallen to the normal level, turn off the engine and open the hood. Nothing else needs to be done - just wait until the engine cools down by itself. It is strictly forbidden to pour cold water on an overheated motor! In this case, microcracks form on the wall of the block head, which will lead to costly car repairs.

After 15 minutes, carefully unscrew the radiator valve. At this time, hot vapors may get on the surface of your hands andcause a burn, so do this when you are wearing clothes with long arms. As soon as the water and vapors go to the side, carefully add the missing coolant to the radiator.

For greater effect, you should forcibly turn on the fan, which will supply cold air to the engine, thereby cooling it (how to do this, we told in the middle of the article).

You need to proceed with extreme caution. You should drive with the cabin heater on at a speed of no more than 50 kilometers per hour. This speed is quite enough for the oncoming flow to blow over the radiator, and the load on the motor will not be so great.

Pay attention

If you need to unscrew the cap of the expansion tank, remember that this should not be done when the engine is boiling. Modern cars are equipped with engines with operating temperatures up to 100 degrees Celsius, while their SOD is constantly working under pressure. And since antifreeze tends to expand when heated, it will push the cork out with incredible force together with air.

The effect will be similar to the flight of a champagne cork. Therefore, during operation, never unscrew it when the engine is warm, and even close it only halfway to allow excess air to escape from the system. Plus, the lid is hot, so burns are inevitable if mishandled.

Conclusion

So, we found out the reasons why the engine is heating up, andalso talked about how to eliminate them. Finally, let's give a little advice. Since it is very difficult to determine the overheating of the engine while in the driver's seat, you should develop a strong habit - after a short period of time, look at the engine temperature arrow. So you can always notice the presence of a problem in time and prevent costly engine repairs.