It's also advisable to inspect the timing belt regularly for any signs of wear, such as cracking, fraying, or glazing. If you notice any of these signs, it's important to have the belt replaced immediately.
In addition to the timing belt, it's also important to replace the water pump when replacing the timing belt on an Audi A4 1.9TDi. The water pump is located near the timing belt and is driven by the same belt. Replacing the water pump at the same time as the timing belt will help ensure that both components are functioning properly and that you avoid any potential issues in the future.