Why does my Vauxhall Astra's engine make a knocking noise?

I recently noticed that my Vauxhall Astra's engine has started making a knocking noise. It only occurs when the car is idle at a stoplight. What could be causing this and is it something I should be concerned about?

The most likely cause of the knocking noise in your Vauxhall Astra is low oil level. You should check your oil level and top it up if needed to see if the noise goes away.

Another possible cause could be worn or damaged engine bearings. It's best to take your car to a mechanic for a professional diagnosis and repair.

If your car is equipped with a turbocharger, the noise could be caused by a malfunctioning wastegate. This is another issue that should be addressed by a mechanic.