crankshaft or injector noise???

2006 55 touareg 3lt v6 diesal
Started make a slight noking noise the other day then it got louder.
When you start the car you need to leave it for a while before the noise comes back, and when you rev it, you can hear it no problem!

Now i had it diagnosed by a friend who thought it could be an injector, but have done some more searching and think it could be something to do with crankshaft!

Help is what i need!!

Link to the video for sound refrance

https://youtu.be/33Og_4bAmic