In the summer, and not only, the question may arise of what to do if the car boils. The problem can arise for several reasons, sometimes it is a malfunction, in other cases it is an oversight of the driver himself. But, in any case, it is necessary first of all to weaken the effect of high temperatures on the engine, and only then look for the cause of boiling. Do not forget that overheating is very dangerous for the motor, you need to know how to avoid problems in the future. There is a clear algorithm of actions in case of overheating, if you do everything as it should, then the risk of complications will significantly decrease.
Signs
What to do if the car boils? For a start, it's helpful to know the signs of such a problem. In this case, you will be able to take timely measures to prevent the situation. Therefore, to begin with, consider the process of boiling through the eyes of the driver.
The first thing to look out for is the change in engine temperature. All modern cars demonstrate this indicator on the dashboard. Normal operating temperatures range from 85-90 ° C. Anything higher is a potentially hazardous situation. At a temperature of 100 °, the coolant boils. In this case, steam is observed coming from under the hood. If you do not react to this condition, then the deformation of the parts will occur. power unitand it will stall.
What to do?
You stretch through traffic jams, and in the process of driving you noticed that the engine temperature began to approach 95 °. In this case, the most the best option will stop the car and let it cool down. When driving at a low speed, the cooling efficiency decreases, due to the lack of blowing of the radiator with the oncoming air flow. If you cannot stop (in a dense stream), it is not always possible to snuggle to the side of the road, then you should turn on the stove. This way you can "draw" some of the heat from the motor. The coolant heating level will decrease; the disadvantage of this method is the heat in the cabin. But, on the other hand, you can avoid boiling.
It is much worse if you still boil. In this case, you need to stop urgently. If there is no visible steam, but the sensor indicator is close to 100 °, it makes sense not to shut down the car, leave it to work at idle with the stove on. The temperature will drop gradually. Stopping the engine in this case can lead to several serious problems. When the engine is not running, coolant is not pumped through the system. Remaining motionless, almost boiling antifreeze will quickly heat up the motor in different places, and cause deformation of parts. Also, when it boils, it can create steam locks, which will reduce the efficiency of the cooling system.
It is much worse if steam poured out from under the hood. In this case, you should immediately stop the car, further movement can lead to the most serious consequences, including engine seizure. After stopping, carefully open the hood. Steam escaping from the cooling system is hot enough to cause severe burns. Sometimes, steam knocks out the radiator cap, if it is in place, then it should be removed. This should be done very carefully, again due to the high steam temperature. Some cars have a bypass valve radiator. They release steam, in this case, do not touch the radiator cap, wait 10-20 minutes until the antifreeze cools down.
Some drivers make a serious mistake; they try to dilute the boiling antifreeze with colder. If you do this at the time of boiling, then most likely the cylinder block will deform, in some cases it may burst. This is especially true for motors with a cast iron block. Add a new portion of coolant only after the engine has cooled down to 70 °.
In winter, the engine needs 10 minutes to cool down, in summer the wait can take up to half an hour. Before moving on, pay attention to some points. Be sure to check the level of antifreeze. When boiling, it actively evaporates, you will probably have to add a fresh portion. You cannot drive with a lack of antifreeze. Be sure to bleed the system when adding fluid. This is done by squeezing the lower hose connecting the motor and radiator. At the same time, air bubbles will come out of the radiator. After this procedure, the level of antifreeze will decrease, add it, and repeat the pumping.
Be sure to check the oil level. It shouldn't get bigger. Also inspect the dipstick. The oil should be clean, free from whitish foam. If you see that the grease has turned white, it means the gasket under the cylinder head is burnt out. This caused antifreeze to enter the crankcase. In this case, you cannot start the engine. You should take the car to the service by a tow truck.
Sometimes, car overheating is caused by a jammed thermostat. In this case, the liquid will race only in a small circle (inside the engine) of the cooling system; such a malfunction can be identified by a cold radiator. Continue driving with such a breakdown carefully, be sure to turn on the stove, and stop often. Check if the fan is working.
Conclusion... Many drivers are faced with various cooling system malfunctions. Usually, the first question that arises is what to do if the car boils on the road. You don't really need to do anything complicated. Simple enough steps will help you avoid further problems.
Although this happens quite rarely, it still happens that boiled diesel engine ... This is mainly due to the carelessness of car owners - a person simply does not monitor the temperature of the coolant. And as soon as the needle of the sensor takes a stable position in the area of \u200b\u200bhigh temperature, various unexpected surprises can occur. The most common is diesel engine overheating.
In principle, the engine can boil in any season - both in summer and in winter. But most often such cases occur in the spring, which is explained quite simply. The point is that in winter time all automotive systems, including the cooling one, work with increased loads. Large temperature differences - minus temperatures at night, and after the start of movement, rather high positive temperatures - have a negative effect on almost all units and assemblies.
How to detect overheating
It would seem nothing complicated - you just need to look at the temperature sensor more often. However, not everything is so obvious. After all, if there is heavy traffic on the road, the driver may not immediately notice the dangerous movement of the temperature arrow into the red zone. Especially if it happens on city streets, when all the attention is focused on driving. But there are several signs that a diesel engine is in danger of overheating and that it might boil - you don't even need to look at the gauge to do this.
For example, if the level of the coolant in the system has decreased, then the heater will react to this first - it is located at the highest point of the cooling system, so the coolant will stop flowing there. A similar situation will occur if diesel engine boiled - after all, usually the boiling process begins to occur in the hottest place - near the combustion chambers of the cylinder head, after which hot steam plugs immediately form and block the passage of antifreeze or antifreeze to the heater. As a result, hot air is not supplied to the passenger compartment.
Also, the critical state of the cooling system will be indicated by a sudden detonation. When the diesel engine overheats, the temperature near the combustion chambers rises much higher than the optimum, which begins to provoke abnormal ignition fuel mixture - as a result, when the fuel pedal is pressed, the diesel engine responds with a characteristic metallic knock.
But most drivers may not even notice these signs - after all, if it's warm enough outside, then the heater is simply turned off, and with high-quality noise insulation of the cabin, you may not hear detonation. In this case, the engine can boil very quickly. But if no action is taken, the engine power will begin to decrease, moreover, a knock will begin to be heard more uniform and strong than during detonation. It is known that when heated, objects expand - the same happens with pistons, as a result, the pressure on the cylinder walls increases, the friction force increases significantly. If the driver ignores these signs, then when further movement the motor can be severely damaged and will require a major overhaul.
Why does diesel engine overheat and boil occur?
A diesel engine can overheat and boil for various reasons. But the main ones are an insufficient amount of coolant and malfunctions of the cooling system or any of its elements. Very often this happens due to contamination of the radiator - it is clogged with foliage, midges, poplar fluff, dust. Therefore, you need to periodically remove it and clean it - you can do this compressed air... You also need to carefully monitor the health of the thermostat, fan, temperature sensor. Scale in the radiator can also contribute to overheating, but not because of water, as it was before, but because of the use of various sealants.
Thus, if you do not want to diesel engine boiled Your car, you need to carefully monitor the condition of the cooling system and the amount of liquid in it. And at the first signs of a malfunction, contact the service station.
They will tell you how to act correctly if your car "boils".
Inattention of drivers
Nine out of ten times, according to auto instructors , the reason for the emergency stop in summer is the overheating of the car. And most often this happens due to the elementary negligence and inattention of the driver.
Remember, when the arrow of the coolant temperature is rapidly creeping up, and the radiator fan for some reason does not work, immediately turn on the emergency gang, change lanes, push to the side of the road and stop.
Find out the cause of overheating and let the vehicle cool down.
Fast reaction
The main thing is to act quickly and without delay. If you see puffs of steam from under the hood, turn off the engine immediately. If the temperature arrow moves into the red zone, it is not at all necessary to turn off the engine. Turn off the air conditioner and turn on the stove. Of course, in the salon it will immediately become like in a bath, but on the other hand, you will bring down the temperature a little.
Instantaneous shutdown of an overheated engine can lead, so to speak, to a "thermal" shock, when the coolant begins to overheat at the points of its contact with the most heat-stressed parts of the engine and the formation of steam locks.
The result will be, for example, a deformation of the cylinder head or other troubles that require subsequent repair.
Rules for "boiling"
So, you are in a traffic jam, the car has warmed up, but the temperature is not yet in the red zone:
- If there is steam, turn off the engine, carefully open the hood. Never open the plug, otherwise you could burn yourself with the steam!
- If there is no steam or coolant leaks, we bring the engine up to 1500-2000 rpm. On a car with automatic transmission, turn on N or P.
- If the temperature continues to rise, and not hot air comes from the stove, we turn off the car and let it cool down. Only then can you try to find the reason.
- By the way, 1.5-2 liters of cold water, which must be poured onto the radiator, helps to cool the unheated engine.
- If it did not work to stop overheating, we check the coolant level, but the machine must cool down until you can hold your hand on it. If the level is low, add coolant or water.
- Check the engine oil level. If it is increased, then you cannot start the car. Most likely, the gasket between the cylinder block and the "head" has "punctured". It will be useful to check the pump (generator) drive belt.
- Start the car and see if there is a leak. Next, we remove air from the cooling system.
- If there are no leaks, white smoke of exhaust pipe, and the engine no longer overheats, you can continue driving.
- The next day, be sure to check the coolant and oil levels and leaks again.
Overheating reasons
There may be several reasons:
- leakage of the cooling system;
- the presence of air in the system;
- there is no pressure in the system;
- thermostat defect;
- pump defect;
- breakage or insufficient tension of the pump (generator) drive belt;
- external contamination of the air conditioner radiator or the radiator itself;
- internal pollution of the cooling system;
- fan viscous coupling defect;
- impeller defect or if the impeller touches other elements;
- failure of the radiator fan activation sensor;
- insufficient density of the coolant when diluted with water.
Video on the procedure for boiling the engine:
Easy and calm road for you!
The article uses an image from the site autopride.ru
We figure out why the car engine can overheat and what steps should be taken in this case.
On combustion air-fuel mixture a large amount of heat is generated in the engine cylinders, part of which goes out with the exhaust gases, and the other part is transferred to the metal parts of the engine (to the cylinder block, block head, etc.). Actually, the purpose of the cooling system is just to remove this heat into environment, and also maintain the engine temperature at a certain level (for most ICEs it is 90-100 ° C). At the same time, the main character of the cooling system is the coolant (antifreeze, antifreeze, water), which circulates through the motor, takes on heat and gives it to the environment through the radiator.
Cooling system malfunctions
1. Tightness
To prevent boiling of the coolant, the pressure in the system is specially maintained slightly above atmospheric. It is controlled by a special valve. If it is faulty or the system is not tight (the radiator is leaking or the pipes are damaged), then the antifreeze will boil, even if the temperature of the liquid does not exceed the operating temperature of the engine.
2. Thermostat
Another cause of overheating can be a faulty thermostat (engine coolant temperature regulator). It is needed to restrict the flow of coolant to the radiator in order to avoid excessive cooling (read - a drop in the operating temperature of the internal combustion engine). Typically, if the thermostat fails, it will jam in the closed position, preventing the coolant from reaching the radiator and cooling (transferring heat from the engine to the atmosphere).
3. Cooling radiator
A separate word deserves a cooling radiator, which is necessary for the direct transfer of heat from antifreeze to the environment. For the heat exchanger to cope with this task, there must be sufficient air flow through it. So, if the radiator cells are clogged with dirt, then the air passes through them with difficulty and the cooling is not efficient enough. That is why it is recommended to thoroughly rinse the cooling radiator after winter.
You can also add an item such as a radiator fan to this item. It automatically turns on, creating an additional flow of air to the heat exchanger (for example, when the car is in a traffic jam and the incoming flow is simply not enough to remove heat from the radiator). If the fan does not turn on at the right time, then the radiator cannot effectively cool the coolant, and the motor temperature begins to rise.
4. Water pump
If you go deeper, then the water pump (pump), which ensures the forced circulation of antifreeze through the cooling system, may also be the culprit for overheating. If the pump fails for any reason, the circulation of the liquid stops, and it simply does not reach the cooling radiator.
Because of what the motor can overheat, of course. Is it dangerous? Definitely yes! The fact is that when the coolant boils in the channels of the engine cooling system air locks... In these places, overheating, expansion and deformation of the metal occurs. As a rule, the cylinder head is especially susceptible to this (there are a lot of internal channels with thin walls). In particular, as a result of overheating, there is a violation of the tight fit of parts, breakdown of the gasket, oil getting into antifreeze, a drop in compression in the cylinders and, of course, complete engine failure.
What to do if the car is still overheated?
If you find that the temperature of the coolant has climbed up, and steam is coming out from under the hood, then you need to get up as soon as possible. safe place on the side of the road, turn off the internal combustion engine and, if possible, turn on the interior heater on full power (this will transfer some of the heat from the engine to the heater radiator and help cool the engine). In this case, the air conditioner must be turned off.
Next, we look to see if the radiator fan is working, check the coolant level in the system (there are minimum and maximum marks on the expansion tank), and also inspect the cooling radiator for damage. If everything is normal, then you need to understand whether the antifreeze is circulating along the circuit (whether the thermostat opens and whether the pump is pumping it). This can be easily checked by touching the upper cooling radiator pipe with your hand - it should be hot. If, again, everything is in order, then all that remains is to contact the autotech center for more detailed diagnostics.
Important! If you decide to add special fluid to the cooling system, then remember: in no case should you open the lid expansion tank immediately after stopping a vehicle with an overheated engine. If this is done, then the pressure in the system will be sharply equal to the atmospheric pressure, which will lead to instant boiling of the liquid and its release outside. Nobody needs burns, right? Moreover, fresh antifreeze can be poured only after the engine has cooled down (for 40-60 minutes to stand with open hood). Otherwise, cracks will appear in the block and the cylinder head from the temperature difference.
The editorial office thanks Vladimir Kladnichkin, an expert of the Vilgud smart car service network, for assistance in preparing the material.
