How to Determine if Engine Valves Are Damaged?
2 Answers
To determine if engine valves are damaged, apply soapy water to the valves. If bubbles form, it indicates valve damage; if no bubbles appear, the valves are intact. The function of engine valves is to control the entry of air into the engine. Once air enters the intake manifold, it mixes with gasoline to form a combustible mixture, which then burns to generate power. The effects of damaged valves include: 1. Unstable engine idle, persistently high idle speed, and difficulty starting the engine, especially during cold starts; 2. No engine idle; 3. Insufficient engine power, poor acceleration performance, and unstable operation; 4. Black smoke from the car's exhaust pipe and increased fuel consumption.
Identifying damaged engine valves requires paying attention to subtle clues during daily driving. For example, starting the car becomes unusually difficult, like climbing a hill, with prolonged cranking before ignition. At idle, the engine shakes noticeably, causing the steering wheel and seats to vibrate, accompanied by a persistent metallic knocking sound—especially louder during acceleration, resembling a small hammer tapping. There's also a significant drop in power; overtaking, which used to be effortless, now feels sluggish, while fuel consumption rises sharply—previously, a full tank could cover 500 km, but now it struggles to reach 400. Exhaust color may also appear abnormal, emitting blue or black smoke, indicating poor valve sealing and air leakage. These symptoms are all warning signs; don’t dismiss them as minor issues. Prolonged valve damage can affect the entire engine’s lifespan. If these signs appear, promptly visit a repair shop for thorough inspection to avoid costly engine repairs later.
