Car cooling system: what it is, how it works, parts, cleaning and purging

do you overheat the engine? Or does it seem like the engine isn't getting hot enough? If the engine overheats, breakdowns can be very expensive: from a blown head gasket to a seized engine. On the contrary, if the engine does not reach its temperature, it will suffer greater wear and consume more fuel and oil. How do you see the car cooling system It is very important.

Often we do not pay all the attention it deserves to the cooling system of our engine, but keeping it in good condition is essential for the mechanism to last as long as possible, avoiding premature wear or overheating that can lead to costly repairs in the workshop. Below we will review the main elements that are part of the refrigeration circuit and its main characteristics.

How does a car's cooling system work?

The operation of the car's cooling system is very simple. The cooling circuit pump (Water Pump), which is driven by the car's engine, activates the circulation of the coolant throughout its entire path with a speed proportional to that of the engine itself. For this the pump sucks the coolant from the bottom of the radiator and drives it into the engine through the spaces between the combustion chamber and the piston liners.

When it has completed its internal tour of the block, the coolant comes out of the top of the cylinder head and returns to the radiator at the top. When it reaches it, it has to go through all the cooling panels in order to lower its temperature thanks to the action of the air that enters from the street (or through the electric fan if the vehicle is stopped).

Thanks to this circulation, the water is maintained at temperatures ranging between 8 to 10 degrees Celsius at the outlet and 80 or 90 degrees at the inlet. This temperature is controlled by a bypass valve (commonly known as thermostat) that monitors that there are no sudden changes of temperature inside the motor and consequently breakdowns arise due to expansion and contraction of the materials.

car cooling system parts

The diagram of the cooling system of a car is made up of the following elements: a radiator, an fan, an thermostat, an Deposit, a coolant booster pump (Water Pump), a belt to move the pump and sleeves They carry the coolant into the engine. All of these components must be in place in order for the engine cooling system to function properly.

The radiator

The radiator is probably the most recognizable part of the car's cooling system. He is usually in the front of the vehicle to receive air as we circulate and thus lower the temperature of the refrigerant liquid that circulates inside it. We should occasionally check that the radiator does not leak and above all, that it is not obstructed. Radiators have very thin metal sheets that, if damaged by small impacts or clogged by dirt, can cause the radiator to not dissipate heat properly, leading to overheating.

With regard to the radiators, it may also be the case that they are clogged on the inside, due to a coolant in poor condition (it should be changed every two years) or to dirt that may be in the circuit. If the radiator is clogged, cleaning can be carried out in a specialist workshop, being a cheaper task than replacing the radiator.

El price of a car radiator can range between 80 and 600 euros approximately depending on the model.

the sleeves

Hoses are another critical part of the cooling system. They are responsible for carrying the coolant from the engine to the radiator. They are usually made of rubber and over the years they get damaged. Take a look at them and if they are not in good condition, replace them with new ones. If a hose bursts we will lose all the engine coolant and we will have to stop if we do not want to cause a breakdown due to overheating that can cost us thousands of euros.

Normally the radiator hoses are specific to each car model and usually cost between 10 and 30 euros.

The water bomb

The water pump is heart of car cooling system. It is responsible for circulating the water throughout the circuit. In many cases the pumps can be damaged and lose refrigerant, so it is advisable to check that they do not have leaks. If it did, it would have to be replaced. When the water pumps are moved by the Timing belt it's advisable change them with every strap change to avoid greater evils. If they are pulled by the auxiliary belt, we will not change it until there are no obvious symptoms of problems.

It may also be the case that the pump blades deteriorate, to the point that it appears to be fine on the outside, but in reality it hardly moves any refrigerant. This is very common in water pumps with plastic vanes.

An water pump for car costs between 50 and 200 euros.

Thermostat

El thermostat is another vitally important element. The motors have to work at a certain temperature and to make sure that the water is at that temperature there is the thermostat. East blocks or opens the passage of water from the engine block to the radiator according to convenience.

If a thermostat deteriorates, it normally stays in the open position. We would notice that the engine has a hard time getting up to temperature and that the idle speed is higher. The engine will generally be running cold and fuel consumption will be clearly higher, in addition to not reaching service temperature, internal engine wear will also be greater.

The car thermostats cost between 10 and 300 euros approximately, depending on whether they are sold alone or come with some other part of the engine.

The fan

The fan is the part in charge of force airflow to the radiator to dissipate heat when the vehicle does not generate enough current (in town for example). Most cars use electric fans controlled by the car's electrical system. They are normally associated with a temperature sensor that activates them if the temperature exceeds certain limits.

It is common the failure of the fan thermal switch, which causes the fan not to work and the motor can be a heater On the other hand, if any of the blades were broken by the intrusion of an object, the cooling could not be adequate, apart from generating noise and vibrations, something more common in SUVs.

in the fans of viscous couplingFurthermore, the airflow may not be sufficient if the viscous core does not work properly. Detecting the problem here can be more difficult with the naked eye, because the blades may be turning, although not enough.

coolant liquid

Finally, all of the above would be useless without the coolant. This liquid is the one that circulates through the circuit and helps to dissipate the heat. It is not convenient to use water, since it can generate oxides in the circuit and it also has a low antifreeze power which, in very cold weather, could cause serious damage to the engine.

To do this, use a suitable antifreeze following the recommendations of the car manufacturer. It's advisable change it every two years approximately to prevent deterioration and keep the cooling circuit clean. those of the brands krafft, ICE-Pro, Motul y Motor kit are good examples. The following article can help you know which one is suitable for your car and which ones can be mixed:

Temperature clock

To control the cooling system of the car while we drive we only have one tool, the temperature clock. This is an element that in many cars has ceased to exist, being replaced by a blue light that indicates that the engine is cold or a red one that indicates overheating.

The temperature clock is useful to see if there is something wrong with the cooling system. However, if it marks incorrectly (under or over) it could be due to a problem with the clock itself or with the sensor that sends the signal. It could also be a mass problem.

Replacing the temperature sensor is easy and inexpensive, being a replacement that usually costs around 20 euros. If the problem is in the clock of the panel, the failure can be more expensive, since sometimes it could involve changing the entire clock panel.

How to clean a car's cooling system

Clean cooling system The car is a very simple maintenance task that, in addition to removing accumulated dirt, will help the engine perform better. This can be carried out by anyone without the need to use complex tools.

Before starting this task, we must make sure that we have a series of elements. Gloves and protective glasses, various containers with and without lids, various screwdrivers and wrenches, a fine, soft-bristled brush, hose with gun or diffuser of water and antifreeze liquid to refill the radiator once the process is finished.

The steps to take for cleaning the cooling system are:

• Before starting the task we must make sure the car engine is completely cold. If it were hot, when opening its cap, the antifreeze liquid could jump into our faces and consequently burn us.
• Open the hood and fix it with the safety rod. Once the engine compartment is uncovered, we will clean the area around the radiator with soapy water to remove dirt and insects. Then with the brush we will clean the radiator in the direction of its grids (otherwise they could be damaged). After cleaning, we will rinse the area with the hose and water at room temperature to remove the remains produced.
• Once the radiator is clean, we will proceed to drain the coolant it contains. To carry out this task, we will put on gloves and open the drain valve. To complete this step successfully it is important that all the liquid is collected in a bucket or container where it cannot be poured, as it is very toxic to the environment. When the radiator stops leaking, we will close the valve again.

• When the radiator is empty and the drain valve cap is closed, we will refill it with the help of the water hose. Then we will empty it again and repeat point three until the resulting water is clear. In any case, the same security measures and collection of the resulting water in closed containers will be maintained.
• Once the radiator expels the completely clean water, we will proceed to inspect the condition of the radiator cap, hoses and clamps. In case of finding any problem, they will have to be replaced with new elements.
• When we have verified that the cooling system no leaks no problems, we will return fill the radiator with the new coolant.
• Last but not least, we will have to get rid of waste generated during cleaning of the car's cooling system. The most advisable thing is to deliver the containers with liquid at a recycling point or specialized workshop to send it to an authorized waste manager.

How to bleed a car's cooling system

Once we have cleaned the entire cooling system of the car and filled the radiator, we will proceed to purge it. To do this, with the open radiator cap, we will start the engine for a few seconds.

With this maneuver we are looking for any air that may be inside to come out, since the motor will move all the liquid through the circuit, establishing the real level inside it. Later we will stop the vehicle, check the level again (topping it up if necessary) and close the cap.

Oil in the cooling system of a car

If we meet oil in the cooling system of our car we may have one or two problems.

The first problem that can cause oil to enter the circuit has to do with the pitting or cracking of the head gasket. If this element deteriorates, oil can be introduced into the cooling system, causing the properties of this liquid to be reduced.

To solve it, you have to change the head gasket and clean cooling system as we explained above. In this case, you have to be very careful with cleaning, because the radiator may be clogged in some parts, having to change it if it does not fit.

The second reason has to do with the oil cooler breakage. This element is a kind of water-oil radiator that goes in the engine and when it breaks, it usually mixes the water and the oil.

In any case, the most appropriate go to an official workshop or service to prevent this problem from going from a low-cost breakdown to a high-cost one.

Images 2 and 12 – Pepe Serrano, scott.