Can You Drive with a Leaking Exhaust Valve?
2 Answers
You cannot drive with a leaking exhaust valve. Effects of a faulty exhaust valve on the car: You cannot drive. When idling, the valve closes, and basically no exhaust gas enters to participate in combustion. During engine load operation, a small amount of exhaust gas is reintroduced into the intake manifold and participates in combustion along with the air-fuel mixture. Some cars may experience shaking. The reason for the abnormal phenomenon is: When the cylinder connected to the exhaust manifold via the exhaust gas recirculation (EGR) system is operating, the exhaust gas entering the intake manifold through the EGR valve is the combustion exhaust from that cylinder. This exhaust dilutes the air-fuel mixture under idle conditions, causing all cylinders of the engine to operate abnormally. However, if the high-voltage wire of the cylinder connected to the exhaust manifold via the EGR system is disconnected, that cylinder will not ignite. In this case, the unburned new air-fuel mixture from that cylinder enters the intake manifold through the EGR valve, significantly improving the mixture quality in the other three cylinders. As a result, the engine's idle speed naturally increases instead of decreasing. Exhaust Valve: Also known as an oil separator or pressure control valve. Installed between the compressor outlet and the condenser inlet, it improves heat transfer efficiency in the condenser and evaporator through separation.
Last time I encountered a problem with the exhaust valve leaking, and I drove for two more days—only to regret it deeply. The leak allows the engine to suck in unwanted air, messing up the air-fuel mixture ratio, causing the car to shake like an earthquake at idle, with sluggish acceleration and a sharp increase in fuel consumption. Normally, a full tank could cover over 500 kilometers, but that time it dropped to just over 400. Even worse, prolonged leakage can contaminate the catalytic converter, which would cost thousands to repair, turning a small issue into a major headache. The leak may also cause the engine to overheat, damaging spark plugs and oxygen sensors, posing serious safety risks—insufficient power on the highway makes overtaking dangerous. In an emergency, you can drive slowly for a short distance to a repair shop, say within a dozen kilometers at low speed, but don’t delay. I recommend stopping immediately and contacting a professional technician to inspect the PCV valve or EGR system—after all, both your car and your life are more important than saving money.
