Internal combustion engines generate a lot of heat during operation. In order not to exceed the critical values, a cooling system functions. Its failure leads to serious consequences and expensive repairs. And the more powerful, more complex and modern the motor, the faster and more imperceptibly for the driver it can overheat.
What is the danger of overheating the engine
A critical increase in temperature, at which the properties of lubricants and working fluids can change, often leads to a long, complex and expensive repair with disassembly of the unit, replacement of the list of parts and components. The greatest damage is usually found in the cylinder-piston group, as well as in the exhaust system.
The degree of engine damage also depends on the severity and duration of the overheating. With small excesses in temperature conditions, you can get scratches in the cylinders and a decrease in the elasticity of the piston rings. But, if the engine is “well boiled”, everything from melted pistons, reversed bushings and a broken crankshaft to cracks and deformations of the cylinder head can be expected.
In long inline engines with a large number of cylinders, the block head suffers from overheating more than in short and compact engines. Modern engines develop higher temperatures due to greater recoil. Their operating temperature reaches 105 degrees against 80 in the older engines
The most common causes of overheating
One of the culprits of overheating is often antifreeze (coolant), if its level is insufficient. In this case, air plugs appear in the system, which impede the circulation of the liquid and thus worsen the cooling of the engine. Antifreeze can leave the system through cracked pipes, a radiator that has lost its tightness, or a cracked expansion tank.
Overheating can also be caused by blocked thermostat, when coolant is not circulating through the radiator. And the reason is sometimes a failure of the cooling system pump. This happens due to a broken drive belt or clutch through which it is driven. Or when the electric cooling radiator fan does not turn on due to rotten wiring, sensor failure or switching relay.
Dirty radiators are an equally popular cause of overheating. In the stuffy engine compartment of modern cars, as a rule, there are several of them. And when they get stuck, it gets scary. Difficult access and the impossibility of normal cleaning without removal and flushing disrupt the heat exchange processes in the system, increasing the risk of overheating. And the turbine, intercooler and catalyst located near the engine only exacerbate the situation.
And finally, operating modes also sometimes lead to overheating. The reason can be not only aggressive driving with the pedal “to the floor” or frequent sharp accelerations, but also banal overloading of the car – overflowing with a passenger compartment, an overloaded trunk, furniture on the roof and a trailer.
Anything that can make a car work at the limit of its capabilities, will fall on this list – from degradation of aerodynamics, sand or slush under the wheels, to frequent climbs. And also all kinds of damage and malfunctions – from a flat tire to locking brakes and a worn clutch.
How to know that the engine is overheated
The main sign is the excess of the operating temperature of the coolant. Its values in the range of 80−105°C are considered normal. Anything above that is a sign that the engine is overheating. For vehicles without a temperature sensor, the problem must be “reported” to the driver via a dashboard indicator. Lights up when critical values are exceeded.
If the emergency indicator or temperature gauge does not work or the driver does not pay attention to them, then he will know about the approaching “boiling”: by the steam coming out from under the hood; from vibrations due to boiling of antifreeze; with reduced traction and power drop.
What can you do
When noticing one or more signs of “boiling” of the engine, one should not rush and stop the car in the middle of the road. Certain actions will minimize the negative effects of overheating and possibly save nerves and money.
– First – pull over to the side of the road and stop.
– Do not turn off the engine – together with it, the pump that circulates antifreeze in the system will stop.
– Turn on the heater in the cabin at maximum air flow with the highest temperature. This is one of the safest ways to remove excess heat from the cooling system.
– Then open the hood to improve the flow of cool outside air to the engine and radiators. Important: to avoid scalding, do not open the cap of the expansion tank (to add antifreeze) until the engine is completely cooled.
– When the temperature of the antifreeze returns to normal values, you can turn off the engine. But, if hot air does not blow from the heater in the passenger compartment and the indicator on the dashboard shows that the temperature does not drop, then it is better to immediately turn off the engine. The pump drive belt may have broken or the pump impeller is not turning.
– It is good to turn off the engine if hot antifreeze is flowing on the road – then it is no longer in the expansion tank and it is not known how much is left in the system. After the car cools down, you can add antifreeze or distilled water to the expansion tank. In the second case, remember how much it takes to add coolant concentrate in the appropriate proportion.
– If possible, find and eliminate the malfunctions that caused the overheating. Or call a tow truck to take the car to a garage.
How to avoid overheating
It is better not to bring the engine to this state than to deal with its consequences somewhere along the way. Remember that in the heat, the engine overheats more easily. Therefore, in the summer, try to move without sudden and frequent accelerations. Especially in traffic jams and on the highway.
Also give the engine a regular “rest” by downshifting. Then there is no danger of igniting the air-fuel mixture in the cylinders, and the pistons cool the combustion chamber by actively pumping air through the cylinders.
2023-08-19 00:34:52
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