It is possible that on some occasion, or on several occasions, we have heard a conversation in which it was debated whether use water or antifreeze liquid in the engine cooling circuit. In fact, we may have intervened to give our point of view, but is it really profitable to use antifreeze fluid? Will running water spoil our engine? Let's find out.
First of all we must take into account that the refrigeration circuit is of vital importance for the heart of our car, the engine; as well as the internal lubrication system. So it does not hurt that we take it into account, we know what its function is, we check it regularly and in case of doubt or problem we go to our mechanic. It is better to invest a few euros in the workshop than to break the engine.
Water or coolant?
Without a liquid fluid that is in charge of cooling, the entire circuit and the different elements that make it up are worthless, so, as it is a vitally important element and the one that really absorbs the internal heat of the engine, we are going to lend it the attention it deserves.
Use water or antifreeze liquid, that is the question. Water can be a valid coolant liquid, in fact, in the first engines with these liquid cooling systems, simply water was used. Antifreeze fluids are basically water., although they contain a series of additives that improve their capacities remarkably.
Can you put normal water in the car?
If we remember the chemistry classes of the last grades of elementary school, we will remember that water is chemically called H2O. That “O” stands for oxygen, so can rust and corrode circuit parts. In addition, and continuing with primary classes, water changes its liquid state to solid at less than 0ºC and to vapor at more than 100ºC.
What does this mean? Well, it means that if we use water as a coolant and leave our car parked on the street in certain areas of our geography (and especially at night), there are chances of that cooling system fluid freezing, something that does not interest us at all. On the other hand, the high temperatures of the circuit can facilitate, in certain cases, boiling.
It should be noted that, if for one reason or another we simply use water as coolant, it should not be from the faucet. Tap water bring lime, which would attack and obstruct parts of the circuit in the medium term. Therefore, to use water, that is distilled or demineralized.
Antifreeze fluid is better than water
The advantages offered by antifreeze liquid compared to water They are achieved thanks to a series of additives. These make up for the drawbacks of water by reducing the freezing point to approximately 30ºC below zero, increasing the boiling point by 20ºC or 30ºC and preventing rust and limescale.
Just like curiosity, there are devices to measure the resistance to freezing of an antifreeze. Called antifreeze refractometersThey are very accurate and quite cheap. If you do the test, you will see the enormous difference between water and antifreeze, even if the latter is of low concentration.
In short: antifreeze fluids, although they will not improve the performance of our vehicle, ensure better performance and care of the same comparing it with the normal and current water. We can use distilled water, but it is more advisable to use this type of liquid with additives specially designed to extend the life of the circuit and guarantee better cooling.
In the event of a small leak and you do not have antifreeze fluid on hand, it is okay to top up the coolant level with water until we solve the problem and renew the fluid. And since we are talking about renewing the coolant, it is best to stick to the time indicated by the manufacturer in its maintenance book, which varies depending on each one, although the norm is usually change it every 2 or 3 years.
Like the rest of the car's fluids, filters, elements and systems, it is It is very important to check the level and the visual state of the liquid. coolant frequently. The engine is the heart of our vehicle and, therefore, we must ensure that it does not suffer breakdowns and that everything is in order.
Can you mix water and antifreeze fluid?
The advantages of antifreeze liquid over water, even if it is distilled or demineralized, have become clear. Nevertheless, in emergencies, you have to know that can be mixed water of those types with antifreeze. For example, because you can't find anything else in the stores or because you don't know what antifreeze your car has.
Regarding the latter, it will be better to mix water distilled or demineralized with your antifreeze, than mixing two incompatible antifreeze. In the article about types of antifreeze, we tell you which ones can be mixed and which ones cannot.
What elements make up the engine cooling system and what are their functions?
Once it has become clear why our engine needs a cooling circuit and why the use of specific antifreeze is better than just water, we are going to identify what are the elements that compose it, the function of each of them and where they are located.
Water Pump
La Water Pump It is located at the bottom of the engine and is the responsible for moving the water through the circuit, so its correct operation is very important.
It is composed of some propellers that rotate at higher or lower speed depending on the revolutions of the engine, since the movement is transmitted through a solidary pulley that is moved by the continuous rotation of the belts, either the timing belt or the accessories belt.
internal ducts
Inside the engine has a series of holes that act as ducts. The coolant circulates through them. absorbing the heat that the cylinders give off and that are transmitted through the different internal parts, so it is important that there are no obstructions.
Thermostat
Electronically controlled thermostat
El thermostat It is a valve regulates fluid temperature. When the engine is still cold, the thermostat remains closed so that the liquid does not pass through the radiator and cools down even more; that is, it usually blocks the passage of the liquid towards the radiator until it reaches 90ºC (optimal temperature).
Once they reach those 90ºC approximately, the thermostat will open and let the liquid pass to the main radiator. Therefore, it fulfills two functions: to allow the engine to reach 90ºC as soon as possible and that once that temperature is reached, it does not exceed it.
main radiator
When the thermostat remains open, the coolant, which we remember will already be hot, will circulate to the main radiator, which is located at the front of the vehicle. It will enter through a corner of the upper part of it and will be divided circulating through fine pipes inside the radiator, facilitating its cooling.
The outside air will reduce the temperature and, in case this is not enough because the air circulation is poor, the front electric fan It will activate automatically by sending out a powerful stream of air.
Once the coolant (already at a lower temperature) leaves the radiator, will continue its journey through a sleeve until you reach the water pump again, repeating the cycle over and over again.
Expansion tank (where antifreeze is poured into the car)
It is connected to the radiator and is the element that is located at the highest level of all the components of the system. Its function is absorb pressure differences that occur inside the circuit. Were it not for him, the high pressure reached when the temperature of the liquid is high would end up bursting some part of the circuit. When the engine cools down, the opposite would happen, since lowering the temperature would generate a vacuum that could deform a component.
In addition to this main circuit, we find the circuit for heating of the cabin. A second radiator, of much more contained dimensions, is located near the dashboard. The hot liquid that comes out of the engine reaches it through a pipe and runs through its interior. A fan is responsible for generating a current of outside air that will absorb part of that temperature (the air heats up) and will be sent to the different hatches of the passenger compartment ventilation system.
Now we can say what the engine cooling system is for, what liquid fluid should we use, what elements make it up and what function each of them has.
Refrigeration circuit: what is it for?
We must know what the cooling circuit is really for, although it is likely that you already know it. Its main function is to evacuate the high internal temperatures that occur in the engine. Inside the cylinders, at the moment of fuel explosion is when the highest temperature is reached. We are talking about approximately 2.000ºC, although it falls quickly when the expansion race begins. During the exhaust phase and the intake time continues to decrease, until reaching about 150ºC or so.
As the average temperature inside the cylinders is very high, the heat spreads through their walls to all parts of the engine. If our car did not have a cooling system, or suffered a breakdown that reduced its function, the average temperature would rise, causing expansion and deformation of the different parts of the mechanics. This could lead to rubbing of the pistons with the liners of the cylinders (which would end up in seizure in a very short time), burn the head gasket or even to literally crack some of the pieces, especially the cylinder head since it is weaker than the engine block. In short, a very “fat” breakdown.
Other function that the refrigeration system complies with is that of heat the cabin. Yes, the heating is achieved thanks to the heat of the engine. As the coolant is at a high temperature and takes a short time to heat up, we take the opportunity to circulate outside air through a radiator using a fan and let it enter the passenger compartment.
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