After the engine has cooled down
The outside of the engine can be cleaned, but it must be cleaned when it is cooled. If the temperature of the engine is too high and it is in contact with cold water, it may cause deformation or even cracking of the cylinder. The large amount of water vapor generated may cause excessive moisture in the engine compartment, affecting some electrical components, and then prevent hot spots from burning the hands.
Can't wash at high speed
Don't run high speed, you will wash your car right away. The car after running the high speed is in the stage of heat dissipation whether it is the brake or the engine. At this time, wash the car, wash the brake disc with cold water, and lightly cause the steering wheel to shake and heavy, which will cause the brake system to fail and affect the driving safety.
Can't use high pressure gun
Although the engine, fuse box and circuit are waterproofed, do not use a high-pressure water gun to squirt it for a long time. In some cars, there is a reminder on the fuse box in the engine compartment to avoid washing the high pressure water gun here. Although there is waterproof treatment, there is no problem in general rain, but the pressure of the high-pressure water gun is large. Just in case, avoid the driving computer and the outer fuse box area as much as possible.
The fuse inside the car is also not water-proof. If it is washed directly with water, it will easily cause a short circuit and cause the circuit to burn. When cleaning the engine compartment, we should try to avoid flushing the fuse box directly with water. In short, the normal state is not recommended to use a high-pressure water gun to rinse, if you must wash, you must wait until the cold car or avoid the non-waterproof components.
Protect the wrapped wire harness
For more than three years, or a hybrid car, when cleaning the engine, you must use a shrink film to wrap the harness and the fuse box inside the engine. Because of this long time, these plastic parts begin to age and waterproof. It's not going to start, so be sure to protect it before washing. If the vehicle is a long-term (more than five years), it is not recommended to wash the engine with water. Because the seal is not good, it is easy to get out of the car. In addition, the engine can not be washed too often with water, and it is easy to accelerate the aging of the line.