Why does my Audi A4's engine make a loud knocking noise when I start it?

I recently bought a new Audi A4 and have noticed that whenever I start the engine, there is a loud knocking noise coming from the engine. What could be the cause of this and how can I fix it?

This could be due to low oil levels in your engine. Check the oil level and top it up if needed. If the knocking noise persists, it could be a sign of internal engine damage. It is best to take your car to a certified mechanic for a thorough diagnosis.

Another possible cause for the knocking noise could be worn out engine bearings. If this is the case, they will need to be replaced as soon as possible to avoid further damage to your engine.