Why does my Vauxhall Insignia's engine make a loud humming noise?

I recently purchased a used Vauxhall Insignia and noticed that the engine makes a loud humming noise while driving. It's not present all the time, but occurs randomly. What could be causing this and is it something I should be concerned about?

The loud humming noise could be a sign of a faulty alternator or a loose belt. I recommend taking your car to a mechanic to have it checked out as soon as possible. It's better to address the issue early on before it becomes a bigger problem.

It's possible that the engine noise is due to a problem with the exhaust system. I suggest taking your car to a mechanic and having them inspect the exhaust system for any leaks or damage. Ignoring the issue could cause further damage and potentially affect the performance of your car.

Have you tried checking the oil level? Low oil can also cause a humming noise in the engine. Make sure to check the oil level and top it up if necessary. If the noise persists, then it could be a more serious issue and require a mechanic's attention.