What are some common issues with Audi engine knock

I recently purchased an Audi A4 and have noticed a knock in the engine. It tends to occur when the engine is cold and disappears after a few minutes. What could be causing this and how can I fix it?

Engine knock in Audis can be a common issue and is often caused by a buildup of carbon deposits on the valves. To fix this, try using a fuel system cleaner to remove the buildup and improve engine performance.

Another potential cause of engine knock in Audis is a faulty ignition system. This can be caused by worn spark plugs or a malfunctioning ignition coil. Have a professional diagnose and repair any issues with your ignition system.

If the engine knock persists even after attempting these solutions, it may be a sign of a more serious issue with your engine. It's best to take your Audi to a certified mechanic for a thorough inspection and any necessary repairs.