What are the symptoms of a faulty Audi exhaust valve?

[RileyMarie]

Audi exhaust valve failure symptoms: large amounts of white smoke emitting from the exhaust pipe, accompanied by engine shaking, unstable idling, etc. Causes of exhaust valve damage: 1. Quality issues with the exhaust valve itself; 2. Improper use and maintenance of the exhaust valve; 3. Sudden exhaust valve damage after mistakenly adding low-purity gasoline or fuel additives; 4. Aging of the exhaust valve. Audi's lineup includes models such as the A4L, A3, Q5, Q7, and S3. Among them, the Audi A3 has a body length, width, and height of 4343mm, 1815mm, and 1458mm respectively, with a wheelbase of 2630mm. Its engine has a maximum power of 110kW and a maximum torque of 250Nm.