Why do modern engines cook?
Remember when GAZelle drivers always had an empty plastic bottle on hand – to keep the hood ajar? Sometimes a boot was used for the same purpose. Modern engines boil less often, but the consequences can be more serious.
The proximity of a cast iron cylinder block to an aluminum head means that their coefficients of thermal expansion are different – warped cylinder heads are the result of overheating. This leads to head gasket failure. Thin-walled sleeves are also warped.
At the first sign of overheating, react immediately – stop, car!
However, overheating is different.
Instant or slow?
Overheating is like a family quarrel. Some arise instantly – as they say, out of nowhere. Others ripen slowly through the accumulation of discontent. The engine behaves the same way: either day after day and hour after hour it approaches a dangerous temperature line, or unexpectedly for the driver it breaks into the “red zone”.
Slow but sure
Machine overload. They filled the interior with junk up to the eyeballs, used a trailer, loaded the roof rack – this happens especially in the summer. We drove through the city streets, it seemed, without problems, but then we broke into the highway, the right foot presses the pedal … You will not accelerate much on an overloaded car, the cooling from the oncoming current will don’t be as intense – in general you are guaranteed to overheat. The treatment is obvious: reduce the load on the motorthat is, slow down even more.
A similar situation often arises in the mountains. Low gear, accelerator pedal depressed, weak airflow with thin air. The temperature is steadily rising – you have to stop.
Low coolant (coolant) level. If the cooling system is in good condition and there are no leaks, evaporation can cause the fluid level to drop slowly over the day. This is especially noticeable when using counterfeit products.
When the level drops, the circulation of the fluid loses its intensity and then stops altogether. In this case, the cylinder head may warp. It is necessary to monitor the level and not buy antifreeze at the collapse, not even cheap
Soil. The radiator of the cooling system does not become overgrown with dirt right away, but gradually. The dirtier it is, the worse it dissipates heat. In addition, most modern cars have an air conditioning heat exchanger installed in front of it, which is the first to become clogged with dirt – again, gradually. In addition, leaves, poplar fluff and other organic matter are stuffed into the space between them, accelerating the motor overheating. Simple advice: keep the radiators clean and wash them thoroughly from time to time
In modern cars, several heat exchangers are hidden behind the grille. These could be automatic transmission radiators, power steering radiators, an air conditioner condenser and – the radiator of the engine furthest in the direction of the airflow. The whole “sandwich” must be kept clean, otherwise – overheating.
Engine oil. Sometimes this also happens: under difficult driving conditions, a low engine oil level can lead to overheating. After all, oil not only lubricates, but also cools the engine. Overall, check and reload
Immediately and unexpectedly
Snake burst. Well, this is a guard! What diagnosis is there if steam suddenly flows out from under the hood and the coolant, pushed out by pressure, flows out almost immediately. The important thing here is: stop on time. The next steps are obvious – replace the hose, fill with liquid. Most likely for service.
Much the same, only slower, occurs when there is a leak in the engine cooling radiator tubes.
The coolant pump or its drive is defective. This is another “Guard!”. A failure is possible when the impeller blades are corroded or rotate on the shaft. In some vehicles, the coolant pump may be clutch driven; there are also electric pumps.
You can check for this defect by starting a cold engine and looking at the hoses going to the heater. If they gradually warm up to almost the same temperature, there is liquid circulation and the pump is working. If the supply hose is hot and the drain is cold, there is no circulation.
Everything is much easier if your car has an expansion tank connected to the fluid circulation system. Then you see the droplets in the tank. Rumbling – the pump is working.
Broken cylinder head gasket. We’ve arrived! Gases from the combustion chamber enter the cooling system and displace the coolant there. And without liquid, overheating is inevitable. Stop the engine and seek service
The thermostat has died. If it hangs in the closed position, the coolant will not go to the radiator and therefore the engine will boil very quickly. Normal operation is checked with a cold engine. Immediately after starting the engine we take the supply (usually upper) radiator hose. If it doesn’t get hot in any way and the engine is overheated according to the temp gauge, then the thermostat is stuck.
Fan defective. Belt driven fans like the Zhiguli fan are now almost unheard of. As a rule, if the fan did not turn, the broken belt of its drive was to blame. However, he also twisted the water pump, so instant overheating was practically guaranteed.
Today, the impeller is usually rotated by an electric motor, less often a controlled or viscous coupling is used.
The temperature of the motor drops, but the fan still does not work? It remains to try to apply voltage from the battery to the connector of the electric fan. Doesn’t work – stays drive slow and mournful, turn on the “stove” on the hottest air and the highest speed of the heating fan
Radiator/expansion tank cap leaking. The boiling point of the coolant in the cooling systems of modern cars is kept at a high level (up to 125 ° C) due to the fact that the system is sealed. There will be no pressure – the liquid will boil much sooner and the motor will overheat.
The plug may fail on its own or become loose (or unthreaded). With a defective plug you can only go slowly to the repair place and turn the heater on to maximum
Low octane gasoline. Low octane gasoline forces the engine management system to use a late ignition timing, and this increases the chances of the engine overheating. If there is a suspicion of gasoline, then at the next gas station – only at the brand! add regular fuel of course, you can even use AI-98 . with a high octane rating
Engine overheating is a dangerous phenomenon. Severe overheating will inevitably lead to a major overhaul.
- Is the engine “stumbling”? Here’s what you need to check.
- “Behind the wheel” can also be read in Yandex.Zen.
Immediately and unexpectedly? Or maybe the process is slow but increasing? And where is the dangerous line?.. – the experts of Za Rulem answered all questions.
