How to flush the engine cooling system

To avoid problems with the motor, it is necessary to follow the cooling system. Usually the cooling system is not particularly watched, but in vain. The main thing to remember to check the level of coolant and, if necessary, top it up. But it often happens that dirt gets into the cooling system, after which the antifreeze or antifreeze becomes dark, which means that you definitely need to clean the engine cooling system.

Radiator cleaning

The main causes of radiator pollution

If you do not change the antifreeze for a long time, then it may decompose, engine oil may also get into the system, it still happens that scum or rust appears. Since the radiator is located in front of the car, all the rubbish and dust from the roads accumulates on it.


If the radiator is contaminated, it will lead to the fact that thin radiator tubes will become even narrower, therefore the thermal conductivity of the cooling system will decrease. In general, the liquid will begin to circulate poorly and the cooling of the motor will be weak, it will lead to overheating, and overheating will lead to a breakdown of the motor, you will have to do a major overhaul, and this is a very large waste. Therefore, it is cheaper to simply periodically monitor the state of the cooling system. Fortunately, that cleaning is not so difficult.

How to flush the cooling system

It is recommended to clean the cooling system once every 2-3 years. Not so often, you can do the cleaning yourself, but you can contact the service. If the cooling system is cleaned in time, the dirt will not accumulate and the motor will be better cooled.

It is best to do the washing in the summer. The first step is to drain the fluid and see what state it is in. If the liquid is very dirty, then you have to spend more effort when cleaning.

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We must wait until the engine cools down and then you can open the radiator cap. This is necessary in order not to accidentally burn yourself.

flushing the cooling system

Types of cooling system cleaning:

  • internal cleaning - disposal of rust, scale, old antifreeze and other dirt;
  • external - cleaning the radiator from dust, insects, dirt, etc.

Exterior cleaning

The radiator accumulates a lot of dirt and debris, so its cooling properties deteriorate. To make the system more efficiently cool the engine, it is necessary to take and thoroughly blow the radiator, you can not remove it from the car, and simply wash it under strong water pressure. Only it is necessary to ensure that water does not fall into those parts of the car that do not like water.

Internal washing of the radiator and the entire system

To flush the system from the inside, you can use plain water or special flushing agents, and some are even washed with Coca-Cola or acidified water.

Water rinsing

If the machine is new, and the antifreeze is clean and there is no particular dirt in it, then you can simply take distilled water and pour it into the radiator, you can also pour drinking water, the main thing is that it contains less salt.

Then you need to turn on the engine and let it run for 15 minutes. After that, you must turn off the engine and drain the water, then pour clean water again. And repeat the procedure. This should be done until the drained water is completely clean.

But flushing with water is not the best way; scum may appear if the water is not distilled, and in general, hot water may not always dissolve serious pollution.

what to wash at home

Washing with acidified water

After the antifreeze was drained and saw flakes from scale, it is better to use acidified water. To get this water you need to add acetic acid or citric acid, some add caustic soda.

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The easiest way to pour citric acid, because it is easiest to get. At 1 liter of water is 100 grams of citric acid. It is necessary that the solution is weak, so as not to accidentally destroy plastic, rubber and plastic parts.

Such water should be, as usual, poured into the radiator, turn on the engine and let it work so that the engine warms up to operating temperature. Then you need to turn off the engine and leave the car for 3 hours. Drain and see what happened. If the water is very dirty, you will have to repeat this procedure again. Clean water should come out. In the end, you need to pour the usual distilled water, turn on the motor and let it work. Then drain the water, it is necessary in order to clean the system from acidified water.

Rinsing with a special tool

Based on how dirty the radiator is and it is necessary to choose a detergent. For example, acid cleaning products are better suited for descaling; it is better to use alkaline products to clean the system of fats.

flushing fluid

What are the means for cleaning:

  • Acid-alkaline, usually they are rarely used, because they can damage the gum and plastic.
  • Separately acidic and alkaline separately. They should be poured into the radiator alternately.
  • Neutral agents, in which there is no acid and alkali, and cleaning is due to non-aggressive components.

Manufacturers usually add cleaning agents, corrosion inhibitors, dispersants and protective agents to their special radiator cleaning products. As a result, the tool allows you to prevent re-sticking of dirt to the radiator, and protective equipment protects against the negative effects of acid and alkali. There are also such special tools, which include elements that extend the service life of plastic and rubber parts of the system.

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flushing the cooling system мотора

Coke radiator cleaning

Many motorists clean their radiators with Coca-Cola. This is the logic, because it contains orthophosphoric acid, which perfectly removes scale and rust from parts. But also in Coca-Cola there is sugar, which can clog the cooling system. The concentration of acid in cola is high, it can lead to the destruction of the gums in the system. Also in the Coca-Cola there are gases, and if you turn on the engine, then these gases will begin to heat up and expand, which does not affect the motor very well.

So if there is a great desire to wash the radiator with Coca-Cola, then we must wait until the gases go out of the drink. And at the end of the cleaning it is necessary to rinse the system with distilled water.

If you do the washing correctly and on time, the cooling system will work well and the motor will cool well and last longer. And if you change the oil in it in time, it will never break at all, well, the nearest 200,000 km. run exactly.

Next, a video on how to clean the cooling system: