Why does my Audi 80's engine make loud ticking noises?

I recently bought a used Audi 80 and noticed that the engine makes a loud ticking noise when idle. It goes away when I rev the engine, but comes back when I stop. Any ideas on what could be causing this issue?

It's possible that there is an issue with your engine's valve lifters. They could be worn out or dirty, causing the ticking noise. A thorough cleaning or replacement may be necessary to fix this problem.

Check your oil levels and make sure it's clean and not low. Low oil levels or dirty oil can also cause loud engine ticking in Audis. Get an oil change and see if the noise persists.