How to judge whether the car camshaft needs to be replaced?

To judge whether the car camshaft needs to be replaced, you can start from the following aspects:

Vehicle performance
Power reduction: The camshaft is responsible for controlling the opening and closing time of the valve. If the camshaft is worn or faulty, it will cause the valve opening and closing timing to be inaccurate, making the engine intake and exhaust not smooth, which will lead to a significant decrease in vehicle power, feeling weak during acceleration, and difficulty climbing.
Poor acceleration: During the acceleration process, the vehicle may experience setbacks, jitters, or slow responses, which may be caused by camshaft problems. This is because camshaft failures affect the normal combustion process of the engine and make the power output unstable.
Increased fuel consumption: Due to abnormal camshaft operation, the engine's combustion efficiency is reduced, and the amount of fuel injection may increase to maintain normal operation, resulting in a significant increase in fuel consumption.

Engine working status
Abnormal noise: After starting the engine, if you hear a continuous, sharp metal friction or knocking sound inside the engine, it may be caused by severe wear of the camshaft and excessive clearance between the valve tappet, camshaft bearing and other components. This noise may be more obvious when the engine speed changes.
Intensified vibration: Camshaft failure may cause uneven operation of each cylinder of the engine, causing the engine vibration to intensify. In severe cases, the car body will also feel obvious vibration, affecting driving comfort.
Difficult to start: The camshaft position sensor failure or the camshaft itself is damaged, which may make the engine control unit unable to accurately obtain the position information of the camshaft, resulting in confusion in the timing of ignition and injection, making it difficult to start the engine or even unable to start.

Fault light and computer detection
The fault light is on: Modern cars are equipped with advanced electronic control systems. When the camshaft fails, the engine fault light will light up. At this time, it is necessary to use a professional fault diagnosis instrument to read the fault code to determine the specific cause of the fault. If the fault code shows problems related to the camshaft, such as camshaft position sensor failure, camshaft phase abnormality, etc., the camshaft needs to be further checked.
Abnormal data flow: The fault diagnosis instrument can also read the engine's data flow and observe the relevant data of the camshaft, such as the signal voltage of the camshaft position sensor, the camshaft phase angle, etc. If these data are significantly different from the standard value, it means that there may be a problem with the camshaft.

Appearance and component inspection
Oil pollution: Check the oil condition regularly. If metal debris or impurities are found in the oil, it may be caused by wear of the camshaft and other parts. At this time, it is necessary to further check the camshaft and other internal engine parts.
Camshaft appearance inspection: After removing the engine hood and other related parts, you can directly observe the appearance of the camshaft. Check whether there is obvious wear, scratches, cracks or deformation on the surface of the camshaft. Especially the cam part of the camshaft, wear is usually more likely to occur here.
The above methods can help to preliminarily determine whether the car camshaft needs to be replaced, but accurate judgment still requires professional maintenance personnel to conduct a comprehensive assessment based on the specific situation of the vehicle and maintenance experience. If the vehicle is found to have the above abnormal conditions, it should be promptly inspected and repaired at a professional auto repair shop.