How to diagnose an oil leak in Audi A4?

I have noticed a small oil leak coming from under my Audi A4. What are the common causes for this issue and how can I troubleshoot it?

First, check the oil level and make sure it is not overfilled. If it is, then it is likely that a gasket or seal has failed and needs to be replaced. You can also look for visible signs of oil leakage around the engine and the oil pan.

Another common cause of oil leak in Audi A4 is a cracked valve cover. It is recommended to visually inspect the valve cover and replace it if necessary. Also, check the oil filter and make sure it is properly tightened.

In some cases, an oil leak can be caused by a faulty oil pressure sensor. If you have ruled out other potential causes, it might be a good idea to have the sensor checked by a mechanic.