Why is my Ford Focus engine making loud noises when I start it?

I have a Ford Focus that is about 3 years old. Recently, I have noticed that when I start the engine, there is a loud noise coming from under the hood. It sounds like a rattle or a grinding noise. What could be causing this and is it something I should be worried about?

It is possible that there is an issue with your engine or exhaust system. If the noise continues, it is important to have it checked by a mechanic to prevent any further damage.

It could also be a problem with your spark plugs or timing belt. These are important components of your engine and should be regularly maintained to avoid any potential issues.

Have you recently changed your oil? If not, it could be old and causing your engine to make loud noises. It is recommended to change your oil every 3-5 months or based on your car's mileage.