What sound does a faulty exhaust valve make?
2 Answers
Exhaust valve failure will produce a whistling sound. When the exhaust valve is damaged, it cannot control the amount of exhaust gas recirculation. Excessive exhaust gas participating in recirculation will affect the concentration of the air-fuel mixture. The car may experience difficulties in starting, engine shaking, unstable idle speed, and weak acceleration, which can impact engine performance. The function of the car exhaust valve is to allow exhaust gas to recirculate into the cylinder for combustion. This small amount of exhaust gas reduces the temperature in the cylinder during combustion. Since nitrogen oxides are generated under high-temperature and oxygen-rich conditions, the formation of nitrogen oxides is suppressed, thereby reducing the NOX content in the exhaust gas. Reasons for exhaust valve damage include: 1. Poor quality of the exhaust valve itself; 2. Improper maintenance; 3. Poor fuel quality; 4. The exhaust valve operates at high engine temperatures, and over time, it will age like the valve cover gasket and rubber seals.
I know all about the sounds of a bad PCV valve. Last time with my old car, there was always this hissing noise from the engine bay, just like a slowly leaking tire - super annoying. It was most noticeable during cold starts, accompanied by a whistling screech that got louder with RPM. The mechanic said it was caused by a cracked valve body creating vacuum leaks - those high-frequency airflow noises were clearly audible even inside the cabin. There was also this uneven idle popping sound, like the engine was hiccuping. After replacing the PCV valve, all these strange noises disappeared, and even the fuel consumption improved. My advice? Don't hesitate when you hear these abnormal sounds - get it checked early to avoid damaging other components.
