Constant control
Despite the equipment for monitoring the temperature and coolant level, you should not rely only on the indicator, but also periodically check the coolant level in the expansion tank in the engine compartment.
- The coolant level can only be accurately checked when the engine is not running.
- The fluid level is clearly visible in the transparent expansion tank even with the cap closed. When the engine is cold, it should be between the markings.
- When the engine is hot, the level is naturally higher.
Adding coolant
A noticeable loss of coolant is a sign of some malfunction or defect. Coolant is not consumed and cannot evaporate from a closed cooling system. Sometimes, when the engine overheats, a small amount of coolant may be squeezed out to the sealing cap. If there is a constant loss of coolant, the cooling system should be checked for leaks as described later in the chapter.
1. If the expansion tank cap is opened when the engine is hot, there is a risk of scalding – so exercise extreme caution.
2. Slowly open the locking cap with a gloved hand or a rag, first by one turn and release excess pressure from the cooling system. Only then unscrew the cap completely.
3. If water is added, the antifreeze is gradually diluted, so add a little antifreeze at once.
4. Do not fill the coolant above the "MAX" mark; the coolant expands when heated and the excess flows out of the system.
5. You can add small amounts of coolant to the top-up tank both when the engine is warm and when it is cold.
6. If there is a significant loss of coolant and the engine is hot, do not pour cold liquid into the expansion tank. Due to "cold shock", the cylinder head may be deformed or the engine block may crack.
Antifreeze
Here the concentration of antifreeze is checked by the analyzer (arrow).
In the cooling system, it is not distilled water alone that provides the necessary engine cooling, but a mixture of water, antifreeze and anticorrosive agent. Therefore, it is more accurate to talk about a cooling liquid or a cooling agent. The ratio of elements in the mixture for European conditions is 2:3, in northern countries 1:1.
|
Engine
|
Freeze protection up to
|
Water
|
Antifreeze
|
| Four-cylinder engine |
–25°C
–35°C |
4.0 l
3.5 l |
3.0 l
3.5 l |
| Six-cylinder engine |
–25°C
–35°C |
3.5 l
3.0 l |
2.5 l
3.0 l |
Ethylene glycol, an alcohol-based liquid that does not evaporate or evaporate, serves as an antifreeze. Just as protection against freezing is important, protection against corrosion is also important. The anticorrosive agent prevents the formation of scale, rust and other corrosion products in the cooling system. Therefore, the coolant filled at the factory cannot be drained in the spring; it remains in the cooling system throughout the year.
Audi workshops use their own antifreeze "G 011 A8 C". In the factory configuration, it is also allowed to use other products that have the mark "in accordance with TL VW 774 C". It is possible that due to a different concentration, other proportions are formed in the mixture, which differ from the information given in the table. Therefore, for the sake of safety, pay attention to the data on the packaging. However, antifreeze from different manufacturers can be mixed without fear.
[The original text of the material can be found on the website AUDIMANUAL.RU]