Is the X-Trail's valve self-adjusting?

[BellaFitz]

X-Trail's valve is not self-adjusting. Here is the relevant information: 1. The function of the car valve is to specifically input air into the engine and discharge the exhaust gas after combustion. From the engine structure, it is divided into intake valve and exhaust valve. The function of the intake valve is to suck air into the engine and mix it with fuel for combustion; the function of the exhaust valve is to discharge the exhaust gas after combustion and dissipate heat. 2. The symptoms of car valve damage are as follows: (1) It will affect the working efficiency of the engine, and the car's power will be reduced; (2) It will produce abnormal noise, the engine will have unstable idle speed or poor acceleration during operation, the overtaking performance will also be reduced, and in severe cases, it will also cause difficulty in starting the engine, the phenomenon of not being able to start, and the car will also have air leakage or increased carbon deposits; (3) The damaged valve will cause unstable cylinder operation, unstable cylinder will cause the engine to shake, the engine will be weak, and it will also cause the exhaust pipe to be blocked, and in severe cases, it will also cause the exhaust to emit black smoke.