Water can be too pure

Coolant: You have to pay attention to this

Incorrect or lack of maintenance of the cooling system can cause expensive damage. The coolant is particularly important. Here are the most important tips to prevent the engine from overheating.

  • Check coolant only when the engine is cold

  • Stop if the engine is overheated

  • In an emergency, only top up with water

In the internal combustion engine things are naturally hot. To prevent it from overheating, the heat is directed to the cooler. Around five to ten liters flow in the cooling system in a pump-driven circuitCoolant from the cylinder head and block to the radiator. The coolant is a mixture of several basic substances: water, monoethylene glycol and additives that primarily act as rust protection. Commercially available concentrates are mixed approx. 1: 1 with water that is as pure as possible and low in lime.

At modern vehicles the cooling system is designed to be almost maintenance-free. However, small leaks can cause a continuous loss of coolant, which is not indicated by the sensors. The cause can be, for example, marten bites on tubes. If the hoses are tight and the coolant level is still falling, the cause could be the water pump or the cylinder head gasket. The driver should get to the bottom of this.

Check the coolant only when the engine is cold

The coolant should only be checked and topped up when the engine is cold or has not warmed up. Because when the engine is warm, the system stops vacuum and opening the lid can cause serious injury or scalding. If cold coolant is poured into a hot engine, temperature stresses can result Form cracks.

The mostly white or transparent coolant tank in the engine compartment can be recognized by the warning symbol "Caution, risk of scalding". The "Max" and "Min" markings for maximum and minimum can be seen on the side. If the engine is still cold, the coolant level should between both marks lie.

If the fluid level is too high, the car should be taken to the workshop. If it is too low, the system must be checked for leaks. Laymen can recognize them by puddles under the vehicle. If the level drops again a short time after filling, there is definitely a defect.

The right mix

When it comes to the coolant, it comes down to the matching mix at. The right cocktail for the engine is from the vehicle manufacturer required and should only be used as indicated. Engines need a mixture of water, the antifreeze monoethylene glycol and special additives, especially for sealing and against rust.

Additives protect against corrosion

Motors and add-on parts are made of different metals and can therefore corrode if they come into contact with water. The monoethylene glycol can also oxidize, producing very corrosive compounds such as carboxylic acids. These processes are accelerated by the high temperatures in the cooling system.

Effective corrosion inhibitors and preservatives such as nitrates, alkali salts of organic acids and benzothiazole derivatives must therefore be added to the coolant. Common coolant concentrates can contain up to seven percent of these materials. These are very special mixtures, the chemical properties of which are often defined in the quality standards of the vehicle manufacturers.

In an emergency, only top up with water

If the right mixture is not available in an emergency, do not fill up with a different coolant initially just water a. The correct mixing ratio with the prescribed coolant can be set later. There are concentrates for this, which must be mixed one-to-one with the purest and most lime-free water possible. In specialist shops there are also ready-made mixes that already contain sufficient water.

Think about the change

The coolant doesn't last forever. Their change is prescribed by the manufacturer. But it is easily forgotten because it is often in the second half of the vehicle's life in which maintenance according to the manufacturer's specifications often no longer takes place. Regular checking of the levels of engine oil, brake fluid and windshield washer fluid therefore always includes checking the coolant tank.

If the engine overheats: it is essential to stop

If the engine overheats, it is imperative that you stop at the next opportunity. Then the Open the bonnetso that the heat can escape. Then the only thing that helps is waiting: the engine block first has to cool down before you can check the coolant level. If there is still enough in the tank, you can take it with you low speed continue driving - but always with an eye on the warning lights and temperature display on the dashboard. To be on the safe side, you should go to a workshop immediately.

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