Hello, simple question, what is this part? It started making a faint rattle sound.

Thanks!

 

That's a shielding/bracket/housing for your engine. The part number is A 274-092-05-34
It comes with different names and according to the site it is to protect the fuel pump.

 

Thanks, sound is then coming from the high pressure fuel pump. It doesn't have any symptoms only faint sound. Not really want to replace it considering the price. Anyone know if it's possible to repair the unit itself?

 

You sure it is a rattle right? Is the side apparent when driving, idling (in the cabin) or only audible when idling or someone revving when you ar standing outside the vehicle? Did you try gently holding on it and see if the sound stops when you try to duplicate the issue?