What can cause the Vauxhall Insignia to have a rough idle?

I've noticed that my Vauxhall Insignia has been idling rough recently. The engine seems to shake and there is also a strange humming noise. Is this something I should be concerned about?

A rough idle can be caused by a few different things. It could be due to a dirty air filter, clogged fuel injectors, or a faulty spark plug. I would recommend getting your car checked by a mechanic to determine the exact cause.

Another common cause of a rough idle is a vacuum leak. This can happen when there is an issue with the gasket or seal in the engine. It's important to get this fixed as it can lead to more serious problems down the road.

In some cases, a rough idle can also be a sign of a failing sensor. The oxygen sensor, for example, monitors the air to fuel ratio in the engine. If it's not working properly, it can cause the engine to run rough. A mechanic can diagnose and replace any faulty sensors.