What are the symptoms of valves not closing tightly?
1 Answers
The symptoms of valves not closing tightly are as follows: 1. Difficulty in cold starting; 2. Unstable idle speed; 3. Body shaking and abnormal noises; 4. Weak acceleration; 5. Severe air leakage may cause the engine to fail to start. Additional information: 1. Whether the valves can close tightly directly affects the engine's starting performance and power output. During engine operation, the intake and exhaust valves are in a state of high temperature and high-speed movement. This rapid opening and closing cause the valves and valve seats to collide with each other, widening the contact surface and creating grooves. The high-temperature, high-pressure, and high-speed environment of the intake and exhaust valves makes the working surfaces prone to carbon deposits, burns, and pitting, leading to poor sealing between the valves and valve seats. 2. When the working surfaces of the valves and valve seats widen, the contact area increases. When the valves close, the unit area pressure on the valve seats decreases (the spring force of the valve springs remains unchanged), and this reduced unit area pressure also results in poor sealing between the valves and valve seats. Therefore, worn valves should be repaired or replaced promptly to avoid the aforementioned issues.
