Reasons for the Ticking Sound in Audi A4 Engine

[HavenRose]

Audi A4 engine has a ticking sound, and the following aspects need to be checked: 1. Many new car owners, after completing their first warranty inspection service, may suspect abnormal engine noise when opening the front cover during idle (because before the maintenance, they were operating inside the car's cabin and couldn't hear the normal ticking sound of the engine under the front cover. Now, hearing this sound is due to the idle state and opening the front cover specifically to listen to the engine noise, naturally hearing the normal operating sound of the engine.) If this sound is not heard inside the car, it's generally not a big issue, usually the sound from the valve or fuel injector. The carbon canister solenoid valve also produces this sound, but it's crisper. One way to distinguish is to slightly press the accelerator during idle and see if the frequency changes. If the frequency doesn't change, it's the solenoid valve sound; if it changes, it's likely the valve noise. If it's still unclear inside the car, it's not a big problem. Vehicles generally have corresponding ticking sounds, one from the fuel injector working, another from the valve area, and a similar sound from the timing chain, but that differs from the ticking sound, having a rattling noise. 2. Generally, when a car starts cold, the engine sound is slightly louder than when it's warm. As long as the sound is uniform and soft, not harsh, it's usually fine. This is because when the engine is cold, the gap between the cylinder wall and piston hasn't reached the optimal size, and the oil lubrication isn't sufficient. Usually, when the engine block temperature reaches about 95 degrees, the sound returns to normal. 3. Oil-related reasons. Poor-quality oil, not changing the oil for a long time, or lack of oil can easily increase friction between the valve and guide, hydraulic lifter, etc., making various engine sounds louder. 4. If still unsure after the above checks, it's recommended to visit the nearest 4S or repair shop for inspection to confirm the fault cause.