Hi I have a 2015 C300 4matic with now 34k miles . I picked it up with 22k on it . The engine seems noisy , I hear a very loud knocks or some whine noise when hood open and I hear it in the cabin , mostly when it’s cold .is this normal ? I attached a video for review .

You Tube

Wow ok thanks . But should you still hear it a little in the cabin area ? Weird with hood open it’s loud but hood closed I door hear it but in the car I do a little

It’s normal