What are the symptoms of a faulty exhaust valve in an Audi car?
3 Answers
In the morning when the car is cold, symptoms such as unstable idling and severe shaking are signs of a faulty exhaust valve in an Audi. The simplest ways to determine if the exhaust valve is faulty are: 1. Start the tachometer; if the RPM exceeds 1000 and the idling is unstable, listening to the sound can confirm the exhaust valve is faulty. 2. If the exhaust valve is damaged, the dashboard will show the engine fault light, but this does not affect continued use. Only after replacing the new exhaust valve and clearing the fault light will normal operation resume. 3. Check if there is blue smoke from the exhaust pipe and whether the engine oil burns too quickly. During acceleration or deceleration, you may feel shaking, and the engine's idle RPM will be about 100 RPM higher than usual.
A faulty PCV valve is quite common in Audi cars. When I was driving an A6, I encountered this issue. The idle became extremely unstable, with the engine pulsating like a heartbeat, and the vibration was noticeably felt inside the car, especially when it was quiet. During acceleration, the power felt sluggish, with delayed throttle response—almost as if towing an extra car—and fuel consumption surged by about 10%, with the fuel gauge dropping rapidly. The exhaust emitted a strong gasoline or sulfur smell, particularly severe when parked, and even rolling down the windows couldn't mask it. More frustratingly, the check engine light on the dashboard kept illuminating, and an OBD scanner often showed P044x codes, indicating a vent line issue. If not repaired promptly, it could damage the oxygen sensor or catalytic converter, leading to even costlier repairs. It's recommended to visit a professional workshop for diagnosis and replacement as soon as possible.
As a car enthusiast, I'm quite familiar with the symptoms of a faulty Audi PCV valve. The symptoms include noticeable shaking at idle, like the engine is hiccuping; lack of power during acceleration, especially when going uphill or overtaking; a significant increase in fuel consumption, for example, city driving that used to be 8 liters now becomes 10 liters. The check engine light usually comes on, and diagnostic tools can read codes like P04DB, indicating a problem with the ventilation pipe. There might also be unusual odors or black smoke from the exhaust. The cause could be a clogged valve body or a cracked diaphragm, and oil leakage can also occur. If you're doing it yourself, checking for oil stains or unusual noises around the valve is simple, but repairing it involves removing the intake pipe, which can easily lead to misconnected lines if you're inexperienced. It's safer to leave it to a repair shop to avoid putting too much pressure on the engine and causing other issues.
