Common problems with the Audi A4's engine

I've noticed an odd sound coming from my Audi A4's engine. What could be causing this?

It could be a faulty camshaft or crankshaft position sensor. These sensors can cause strange noises and should be replaced as soon as possible.

Check your oil levels and make sure they are at the recommended level. Low oil pressure can also cause unusual engine noises.

Have you recently changed your air filter? A clogged or dirty air filter can cause your engine to make strange sounds. Consider replacing it if it's been a while.