Overheating of engine is one of common problems that lead to expensive car repair. Let’s try to figure out what causes engine overheating, its consequences and what to do in this situation.
• Causes of car engine overheating – what is the first thing to inspect?
• Consequences of car engine overheating
• How to identify that your engine overheats?
• Overheating of diesel engine – first aid on a road
• Diesel engine overheats – what else can you do to help?
Causes of car engine overheating – what is the first thing to inspect?
Despite of established opinion of most drivers that engine overheating happens mostly in summer, it’s not true. Among most wide spread causes is incorrect operation of engine cooling system. This may be coolant leak while system containment failure, or one of a car cooling system units breakdown. Among units that are most exposed to failure is water-circulating pump.
If it doesn’t work, or works incorrectly, then liquid circulates through cooling system improperly. Also engine overheating can be caused by failure or wear-out of vane wheel, failure or weak tension of drive belt. Except water-circulating pump, often the cause of weak liquid circulation is radiator. If cooling liquid is of low quality or for some reason you had to add water to the system. This may provoke scale formation in cells, due to continuous exploitation, which complicates liquid circulation. Besides, sticking of various sort of rubbish such as insects, leaves, dust, and mud cause weak heat exchange in radiator.
Another unit, which directly affects engine overheating, is thermostat. But because of low quality or damages this component may function incorrectly. In other words, it is not able to toggle liquid circulation from smaller circle to larger. Besides, the engine can overheat if you pick up incorrect operational mode.
For example, if you constantly use lower gear together with high rpm, it is most likely that in some time your car engine will boil. In winter this will take more time than in summer. Besides, in winter, when snow breaks, overheat may be caused by engine heat insulator, which was installed by driver to protect engine from freezing. Rarely there can be more specific reasons of engine overheating.
Rarely, there are more specific causes of engine overheating. Disruption of cylinder head gasket is among them. In this case there may be 2 options: cooling liquid leaks into lubricating system, or exhaust gas gets into cooling system.
In any case, engine requires repairmen. Further exploitation will make things worse and cause more failures. Often these problems happen with cars, which were standing in garage for a long time.
Consequences of car engine overheating
Human, in comparison to machine is fragile. Even the strongest specimen can fall unconscious in hot summer day in full blaze of the sun with his head uncovered. Car is more solid, but its last is not boundless. Engine overheating is consequence, the severity of which depends on whether there was severe or feeble engine overheating problem was allowed by driver.
If engine overheats weakly
When overheating time does not exceed 5-10 minutes, there is no need to fear serious problems. This can happen because of fan failure or thermostat breakdown. Driver with good reaction shuts down the engine in time. At worst, pistons will melt a bit. But in most cars there will be no consequences from such overheating. But you should worry and send the car to diagnostics only if you see smoke.
Medium engine overheating
When overheating exceeds 20 minutes, the consequences will be more sensible. There might be such problems as:
- integral cylinder head might be twisted;
- there might be cracks in integral cylinder head, which are the main cause of valve cone deport;
- gaskets of integral cylinder head can burn down;
- filler blocks can drop oil, etc.
This is nothing in comparison with severe engine overheating problem, causes of which usually in inattentive car maintenance.
Severe engine overheating is a “heart attack” for a car
Severe overheating usually damages all components of engine. Well, the driver, who experienced such situation, can consider himself lucky, because the engine could explode. Only car system can allow avoiding it, because different parts break with different speed, due to this the car just stalls. The destruction wave moves from compression chambers and spreads over surrounding components:
- pistons start melting;
- melted aluminium from pistons gets to cylinder walls and obstruct a piston-stroke increasing its destruction;
- if the engine didn’t stall after pistons destruction, troubles with oil would start;
- overheated oil loses its lubricating features;
- all friction parts start ruining;
- all melted connecting rod and bearing liners stick to crankshaft;
- valve cones fly out;
- crankshaft falls into 2 pieces under pressure of piston;
- piston breaks through one of walls of cylinder barrel, which completely destroys the engine.
How to identify that your engine overheats?
Well, it seems so easy to track engine overheating with sensor. But often drivers are so busy with driving process that they rarely pay attention to engine overheat sensor. And old cars have no hazard light in case of engine overheating. That’s why you should know few indirect indicators that point on engine overheating. Try to control engine liquid temperature with the help of sensor. If there is not enough of liquid, the first thing that will stop working is heater, because its radiator is on top of cooling system.
Also the heater won’t work if antifreeze substance boils, and the steam forms an air bound system, which blocks liquid flow to heater. Besides, it detonates while engine overheating and knocks when pressing accelerator pedal. All walls of compression chamber expand more, than they must. This causes formation of large leashes. If you continue movement, there power will obviously fall.
Overheating of diesel engine – first aid on a road
Therefore, when diesel engine overheats, the consequences can be severe due to formation of vapor lock in head cooling system (the jacket stops cooling, and the head overheats and fails). This is the most cunning situation, which threatens great losses, if you don’t deal with it. In other cases, the consequences of engine overheating are not that fatal. And in theory, you have some time in store, if you failed to notice it at once.
After overheating, you should find out, why it happened. In most cases, it is caused by worn out junction pipes, damaged radiator, thermostat failure (doesn’t control engine temperature or block cooling liquid flow in time), water pump (leakage) or temperature sensor.
After you detected overheating you should stop the car. Stall the engine and open the hood. After natural cooling of unit, check level of cooling liquid in expansion tank. If cooling liquid level is not within normal range, add it. If you don’t have any coolant, you can replace it with distilled water. Add it only after engine cooled down to avoid deformation over temperature difference.
Diesel engine overheats – what else can you do to help?
After adding cooling liquid, check the fan, condition of thermostat tubes. If thermostat doesn’t work, the lower tube will be cool. This means, that cooling liquid circulates only in smaller circle. In this case, the thermostat must be replaced. Or remove a thermostatic valve to provide circulation through large circle. If you noticed leakage after adding liquid, do everything to stop it or reduce to possible minimum. If adding of a cooling liquid didn’t solve the problem of overheating, inspect the work of fan drive. The problem might be in poor connection or faulty fuse.