What are common causes of engine knock in a Ford Mondeo?

I've noticed a strange knocking sound coming from the engine of my Ford Mondeo. What could be the cause of this and how can I fix it?

One common cause of engine knock in a Ford Mondeo is low quality fuel. Make sure you are using a reputable brand and the correct octane level for your car.

Another possible cause is a faulty spark plug. Have your spark plugs checked and replaced if necessary.

A dirty or clogged air filter can also contribute to engine knock. Make sure to regularly replace your air filter.