Nov 12, 2021 1 841

When and why to change antifreeze in a car

Cooling system car ensures normal operation of the engine, preventing it from overheating. And one of the main roles here is played by the non-freezing liquid circulating inside the engine - antifreeze. The performance of such engine elements as the pump and radiator depends on its quality. It is also worth noting that dirty or low-quality antifreeze clogs the channels. As a result, the power unit begins to heat up, even if you later poured in fresh coolant.

What is antifreeze

Immediately it is necessary to clarify the terminology. Many people confuse or equate the words "Tosol" and "antifreeze". The latter (“anti” - against, freez - in English “freeze”) means a group of coolants, and not a specific name. The word "Tosol" is the designation of the Soviet brand, which stands for "Theory of Organic Synthesis". It's just that in the USSR there were no other brands of coolants other than this one. Today, the choice is wide: for example, such antifreezes as the domestic Sever, Alaska, Toyota Long Life Coolant, Langzeit Kuhlerfrostschutz GTL, TCL Power Coolant, AGA Z40, AGA Z42 and others are popular.

The main components of antifreeze are alcohol and water, glycerin, plus additives. Today, however, ethylene or propylene glycol is more commonly used. The first is characterized by high toxicity and relatively low cost. The second has a very low (-60 ° C) freezing point.

Why is water worse?

Once upon a time, antifreeze liquid was almost never used due to inaccessibility and high cost. They preferred ordinary water, which had to be drained in the cold season. It would seem that out of economy, someone can do this today. But studies have shown that it is better to use ethylene glycol-based antifreeze:

?Liquid does not freeze in frosts up to -40 С°
? Inside the channels through which the liquid moves, scale does not form, which reduces the throughput of the lines
?Most coolants (coolants) provide anti-corrosion protection of engine parts

How antifreeze works

Without it, the motor will not work even for 20 minutes: pistons, cylinders will expand and jam from overheating. Antifreeze thanks to the pump circulates between the cylinders and the walls of the power unit. Then the liquid is sent to the radiator, where it is cooled. The cycle is repeated. As a result, heat is efficiently removed from the engine block and its head. To control the temperature, a sensor is installed: the information it produces is displayed on the dashboard.

What antifreeze choose

This fall, the choice of coolants on the market is simply huge. To navigate this flow of products, you should go to sites where motorists leave reviews about the quality of the product. Based on their results, rankings are published on the Internet.

SINTEC ULTRA G11 (Russia)

Can be used in petrol and diesel engines. It has a red or pink color, freezes at -45 C°, boils at +112 C°. Of the minuses, it is worth noting the change in shade to purple after washing, there are many fakes.

When and why to change antifreeze in a car

Antifreeze SINTEC ULTRA G11, price 1 liter 160 rubles. Photo: YandexMarket

FELIX CARBOX (USA)

One of the most common American antifreezes. Resource: 250 thousand kilometers or 5 years of operation. Boils at +110 C°, crystallizes at -42 C°. It acts on the sources of corrosion, suppressing them. Red color, no inorganic additives.

FELIX CARBOX antifreeze, price 1 liter from 205 rubles. Photo: YandexMarket

CASTROL RADICOOL SF (Germany)

Can be used for 5 years. It is well combined with engines made of aluminum, cast iron. It has a red color, requires dilution with distilled water before use. Freezes at -37 С°.

German antifreeze CASTROL RADICOOL SF Price 1 l 890 rub. Photo: YandexMarket

MOTUL INUGEL OPTIMAL ULTRA (France)

The composition of the liquid does not contain phosphates, silicates and other chemicals that corrode plastic, rubber parts. Shade - red, lasts up to 5 years. Compatible with gasoline and diesel engines installed on cars, trucks, buses. Boils at +136 C°, freezes at -37 C°.

Coolant from France MOTUL INUGEL OPTIMAL ULTRA. The price of 1 liter is 580 rubles. Photo: YandexMarket

When automakers recommend changing antifreeze

It is necessary to fill in fresh liquid after an average of 2 years or 60-80 thousand kilometers. Only in this case is the ideal condition of the parts washed with antifreeze guaranteed. But it is worth noting: the deadline for using coolant from well-known brands can be significantly longer - up to 5 years. And the latest G13 lobrid coolants based on polypropylene glycol serve for 10 years.

With frequent trips, it is recommended to replace the antifreeze earlier: after 40-50 thousand kilometers. Otherwise, the resistance of the liquid to corrosion falls, the internal cavities begin to become contaminated with metal decomposition products.

The color of the antifreeze changes

A sure sign that it's time to change the fluid. The appearance of a shade other than when buying, most often indicates the end of the life of the coolant. If it was filled not so long ago, then the product is of poor quality. With a slight color change in the case of using fresh antifreeze, we can conclude that the previous product was used for a long time, resulting in a plaque that was washed away by the new liquid.

Nuance: use coolant of the same brand. Often, mixing different antifreezes leads not only to a change in color, but also to a decrease in the performance of the product. If you nevertheless mistakenly filled in the wrong coolant, the best way out is to drain it completely and fill the system with the right brand of antifreeze.

Oil film on coolant

You opened the expansion tank and saw a floating film on the surface, smelled burning. This means that not everything is in order with the motor - it is necessary to carry out diagnostics, to identify the cause of the lubricant getting into the coolant. Most often, this is a rupture of the cylinder head gasket, usually caused by overheating of the internal combustion engine. Less often, oil enters the coolant through cracks in the engine circuits. It is necessary to replace the gasket or repair the cylinder block and then completely replace the antifreeze.

Foam and flakes

They appear in the expansion tank if incompatible brands of coolant are mixed. For example, you used one type of antifreeze, you had a leak, you fixed it and added a different type of fluid. In such a situation, an immediate replacement of the entire coolant in the system is necessary.

For example, below are brands of antifreeze that cannot be mixed:

? AGA Z42: great for all car brands
? Lukoil Antifreeze G12 Red: characterized by a long service life - up to five years
? Sintec Unlimited: a new generation high quality G12+ product made with bipolar technology

If you decide to change the brand of coolant, you will have to flush the entire system.

What happens if the coolant is changed less often than recommended by its manufacturer

In such a situation, the coolant additives that protect the inside of the cooling system from corrosion are the first to begin to lose their performance. As a result, the film on the metal parts begins to break down, rust appears. It spreads throughout the system. Due to the loss of coolant lubricating properties, the pump fails. If the pump is not replaced in time, the drive belt may also break. As you can see, it is cheaper to fill in fresh antifreeze than to buy new parts and flush the cooling system.

How to replace coolant

Put the car on a viewing hole or use a lift. Further:

✪ Unscrew the cap of the expansion tank, and put a pre-prepared container down (preferably a basin)
✪ Unscrew the drain plug or a special radiator tap and, after filling the substituted container, screw them back
✪ Fill in fresh antifreeze to the highest mark on the expansion tank
✪ Start the car, warm up the engine for 15 minutes, turn off
✪ Check the coolant level and top up if necessary

If you don’t want to spend money and run to the store for a new pump, or even a radiator, change antifreeze on time. Buying and installing these parts will take much more time than pouring new coolant. So saving on fresh antifreeze is a very dubious matter.