What's wrong with using a water gun in the engine room of a car?

The engine cannot be washed directly with a water gun. If the car washer directly washes the engine of the car with a water gun, it means that he is unprofessional in car washing. Many people think that the engine compartment is waterproof, so when washing the engine, just wash it with a water gun. In fact, this is not appropriate.

First of all, not all car engines have been waterproof. Some old cars are prone to problems because the previous technology is not perfect, and the electrical components and wiring harness interfaces are not waterproof and sealed, or the seals are not complete enough to meet the specifications and standards.

Secondly, even if these seals meet the use standards of vehicle regulations, problems such as rubber aging and seal damage will inevitably occur after the vehicle is used for a long time, resulting in poor sealing performance. Direct washing with water can't be said to be a problem, but it will definitely increase the probability of problems.

There are many sensors in the engine compartment, such as throttle sensor, outdoor temperature sensor and camshaft position sensor. These precision instruments are bound to be damaged by water, so be careful when cleaning them. You can't wash them directly with a water gun, let alone use a high-pressure water gun.