With the continuous progress of social economy, science and technology, automobiles play an increasingly important role in people's daily lives. It is not only an important means of transportation, but also the crystallization of human wisdom. In the process of using cars, the engine plays a very important role. The engine is the "heart" of the whole car. The operation of the engine will directly affect the power performance, economic performance and even environmental performance of the vehicle. Therefore, one of the most important steps before using a car is to conduct a sound safety inspection of the engine to ensure that the car can better serve humans after it is put into use. This paper analyzes the importance and precautions of automotive engine testing to understand the importance of automotive engines in the new era.
After a basic security check, there are still some things to be aware of. For example, it is necessary to troubleshoot car engines. Fault diagnosis mainly includes electrical fault diagnosis and mechanical fault diagnosis. Electrical fault diagnosis begins with an understanding of the distribution of electrical faults. From the engine control unit to the sensors, actuators and general wires, detailed fault diagnosis should be carried out, such as whether the wires are clamped, whether the adapter is clamped, whether the contacts are oxidized or deformed, etc.; then we need to perform a fault query of the system to check whether the circuits of the sensors and actuators are in good condition. In addition, we need to check the electrical components of the engine, including switches, motors, electronic valves, door locks, relays, etc. If necessary, we can perform resistance tests on electrical components. If the resistance measured twice is equal, the circuit is normal.
Mechanical fault diagnosis is the analysis of fault conditions based on the mechanical operation of the engine. If the engine has abnormal noise during operation, first determine the type of abnormal noise, including mechanical abnormal noise, abnormal combustion noise, aerodynamic abnormal noise and electromagnetic abnormal noise. Different abnormal noises are caused by different causes. For example, most abnormal mechanical noise is caused by aging, wear, poor lubrication and poor tightening, while abnormal combustion noise is mainly caused by the unstable operation of the machine when the engine is burning. Many other methods can also be used to diagnose engine mechanical failures. After starting the engine, use the stethoscope to observe and listen to both sides of the cylinder. Idling may occur if the sound is clear and powerful, with a rhythmic metal tapping sound; if the sound is significantly reduced by half, or if the sound disappears, there may be a single-cylinder fire extinguisher; and at the same time, check the engine temperature while listening to the sound. If a sound is emitted when the engine temperature is low, but the sound disappears when the temperature is normal, it may be that the gap between the piston and the cylinder is too large.
In general, the inspection of the car engine is very important, and there are many items and contents that need to be checked. In the inspection process, the staff should not only carry out a comprehensive inspection, but also combine different inspection methods to carry out appropriate fault diagnosis after inspection to eliminate safety hazards and improve the safety performance of the engine. The use of cars is related to the safety of passengers and passers-by. In the process of inspection, it is necessary to maintain a strict psychological state, pay full attention to it, and truly implement the engine safety inspection work.