Why does my Audi 80 engine make a clicking noise when accelerating?

I have an Audi 80 with about 150,000 miles on it. Recently, I have noticed a strange clicking noise when I accelerate. It only seems to occur when I am driving at higher speeds. Any ideas what could be causing this issue?

Based on your description, it sounds like there may be an issue with the valves or lifters in your engine. It's important to have this checked by a mechanic as soon as possible to prevent further damage and costly repairs.