What are the symptoms of a faulty exhaust valve?
3 Answers
Exhaust valve failure symptoms: The exhaust gas recirculation valve does not close tightly, the malfunction indicator light flashes, engine shaking, unstable idle speed, engine RPM increases instead of decreasing, leading to significant blue smoke emission, etc. When encountering these situations, it is essential to conduct timely inspection and repairs. The exhaust valve is also known as an oil separator or pressure control valve. The engine exhaust valve is primarily responsible for controlling the exhaust gases produced during vehicle combustion. The working principle of the engine exhaust valve is that the high-pressure gas from the compressor enters the exhaust valve and then the guide vanes of the exhaust valve, flowing in a spiral pattern along the vanes. Through centrifugal force and gravity, the lubricating oil is separated from the working gas and flows down along the inner wall of the cylinder.
The symptoms of a faulty exhaust valve are quite obvious. The car idles unevenly, feeling like it's shaking, and acceleration becomes sluggish with no power, making overtaking difficult. Fuel consumption skyrockets because the valve doesn't close properly, allowing exhaust gases to disrupt combustion efficiency. It may also emit black smoke or foul odors, making it prone to failing emissions tests. Engine noise might increase, sounding creaky. Having worked in car repairs for years, I've seen many such issues—it can trigger the check engine light, and prolonged neglect can damage engine components. I recommend checking the valve every 5,000 kilometers and promptly visiting a repair shop if any abnormalities are found, to avoid unnecessary expenses and safety risks.
My car had a faulty exhaust gas recirculation (EGR) valve before, and the symptoms were severe shaking at idle, like an earthquake. When accelerating, the car lacked power and struggled to climb hills. Fuel consumption skyrocketed—what used to be a full tank for long trips suddenly fell short by 100-200 kilometers. The exhaust pipe also emitted black smoke with a pungent smell. Things only improved after repairs. Since then, I inspect the exhaust system every quarter to avoid further trouble. Paying attention to these signs while driving allows for early detection and resolution, saving money and peace of mind. Never delay—I’ve seen a friend’s car overheat and get scrapped because of this.
