What is the most common cause of engine failure in Audi 80?

I've noticed that my Audi 80's engine has been struggling lately. What are some potential issues that could lead to engine failure in this model?

It's important to regularly check and replace the oil and oil filter in your Audi 80. This can help prevent engine failure caused by sludge build up.

Another common cause of engine failure in the Audi 80 is a faulty timing belt. Be sure to have this component checked and replaced if necessary.