Usually drivers face the problem of flushing the engine cooling radiator in the summer time. In the heat the engine often overheats because of insufficient cooling, due to contamination of the cooling system radiator.
This system is designed so that clogging and insufficient heat removal occur not only due to external factors such as dirt, debris and the rest of it that a car comes across on our roads, but also because of internal factors, i.e. decomposition of antifreeze solution, rust, scum inside the system.
The engine cooling system can be flushed out by several methods. Which one to choose depends on the contamination level.
Cleaning with distilled water
This method is suitable for new cars that have no obvious visual signs of contamination. To flush out the system using this method, distilled water is needed, which eliminates the scum in the radiator. It is obvious that tap water with a large amount of salts and impurities is not suitable (look at your kettle after using tap water). Clean water is poured into the radiator and the car starts at idle speed. After 20 minutes of operation in this mode, the water is drained and a new one is poured.
Cleaning with acidified water
There can be scum in the engine cooling system, which clogs the system over time and makes it difficult or even impossible to operate. Unfortunately, conventional flushing with water will not help here. In this case, a special dilute acidic solution is prepared containing vinegar, caustic soda or lactic acid.
Flushing with such a solution is similar to flushing with distilled water, the only difference is that after a car running at idle speed, the liquid is not drained, but remains in the system for 2-3 hours. The scum is removed after three such procedures. Then it is necessary to wash the system with distilled water once, as described above.
When cleaning with citric acid, you will need 100-120 g per 5 liters of water, and if you are going to flush out the system with acetic cleaner, then you should take 500 ml. of 9% vinegar per 10 liters of water.
Flushing the cooling system on Reno
Flushing the cooling system on the Audi 100
Some car owners even use caustic when flushing, but you have to be very, very careful in this case, because caustic soda can only be used to flush copper radiators! The solution for such flushing is prepared in the amount of 1 liter of distilled water and 50–60 g of soda. This substance corrodes aluminum radiators and cylinder blocks!
Cleaning with special cleaners
There are special fluids for cleaning the engine cooling system on the market. They contain various chemical solutions that can remove different scum and sediments in the system. Herewith, they clean the car components gently and do not damage them. Such cleaners can be purchased at autoshops, and the way to use them is indicated on the packages. It must be said that it is the same as with water, i.e. the fluid is poured into the radiator and the car runs at idle speed. After flushing, it is necessary to wash off the cleaner with distilled water.
Cleaning of the radiator external elements
The cooling system requires care not only from the inside, but also from the outside. Dirt, dust, sand, and fluff are clogged between the radiator ribs and impair heat exchange with the air environment. Use a blowdown or flush to clean the radiator.
Be very careful with the water pressure and physical effect, as you can bend the radiator ribs, which aggravates the failure even more.