The question of whether it is necessary to wash a car engine is rhetorical. Yes, it needs to be washed, but the point is how intensively and in what sequence to do it. Let's take a look at the nuances of such cleaning procedures.
When to wash the engine
In theory, the engine compartments of modern cars are well protected from pollution. However, if the car is not new, drives in heavy duty, especially off-road, you should pay attention to cleaning the engine compartment.
Here the radiator is most polluted, in the cells of which leaves, sand, salt and insects fall. This creates a kind of blockage in the airflow path, causing the engine to overheat, and the often humming cooling fan is a sure indicator of this process.
Auxiliary radiators (oil coolers and automatic transmission radiators), which are usually installed deep in the engine compartment, also need to be cleaned. So, if your car is more than five to seven years old and you often drive on uneven and dusty roads, they should be washed.
You need to clean it regularly, and in case of severe pollution, thoroughly wash the battery and dirty wires. The thing is that oiled electrical equipment provokes a leakage of current, which leads to a deterioration in engine starting and a rapid discharge of the battery. Of course, you also have to fight against the formation of oil leaks on the walls of the engine, because these contaminants can ignite. With a clean engine, leaks are immediately noticeable, allowing you to quickly respond to the first signs of a malfunction.
How to clean the engine compartment
Probably, many have seen this picture - a car wash employee directs a jet of steam to the engine and begins to rinse it at a pressure of 150 bar. With such a sheathing, it is very easy to damage electrical cables, various relays and sensors, although the latter are usually covered with protective covers. Another hazard is water entering the spark plug area. And if the generator is flooded, the insulating material can be damaged, which will lead to corrosion of the diode bridge, oxidation of the diode contacts and, ultimately, the device will fail.
Hence the logical conclusions. Before washing the engine compartment, insulate its “delicate parts”. The same generator, wires and sensors need to be wrapped in foil or at least covered with nylon or something waterproof. The contacts can be protected with special water-repellent chemicals.
This will protect the non-ferrous metal joints from corrosion. And as it already turned out, the engine compartment cannot be washed under high pressure - no more than 100 bar. Then everything should be dried and, if possible, blown through the wet parts of the engine with compressed air. Dry electrical contacts very carefully.
If you do not want to risk flooding or damaging critical components and electrical cables, you can resort to steam flushing the engine. The essence of the method consists in supplying dry steam with a temperature above 150 degrees Celsius under a pressure of 7-10 atmospheres to the contaminated external elements of the engine. This effectively removes dirt and oil stains, and does not accumulate moisture in the electrical contacts. The disadvantage is the complexity and high cost of the procedure. In addition, steam washing should only be performed by qualified personnel due to the risk of thermal injury.
Another effective way to clean the engine compartment is chemical. Auto parts stores have a huge selection of chemicals - various sprays, shampoos and cleaning solutions. Or, if you prefer, you can use household products such as regular soap and warm water. In the latter case, you need to warm up the engine to about 40 degrees, apply the solution with a rag or sponge, wait a quarter of an hour and then remove the dirt without using a lot of water.
Dry cleaning is also used. Namely, a special liquid or foam is applied to the contaminated parts. It is not necessary to wash off the applied substance with water, the chemistry will do everything itself. However, before using such a tool, it is necessary to warm up the engine, but again not to a hot state.
Finally, experts recommend not cleaning oil stains on the engine casing with gasoline, diesel fuel, kerosene and other flammable substances. Although such substances are effective solvents and can be easily removed from the engine surface, they are highly flammable, so you should not play with fire in the truest sense of the word.