Hi All, First post so hope you don't mind me opening with a question. I've just bought a 2003 C240 Avantgarde and on comparing engines with another of the same, I've noticed there's something missing under the bonnet.

I've attached an image and circled the missing item.

Can anyone identify it for me please and give me a brief description of its function?

Thanks in advance and looking forward to meeting all of you along my journey through the forum.