2012 c 220d c class engine noise

[Mymercedes220]

Hello
My wife's car makes strange noise on start up. It's got a fair few miles now and when you start it, there is this loud growling , roaring noise underneath. It lasts for about 3 or 4 seconds then stops .
Anyone have any wild ideas Or has the same noise?

 

[alcmackew]

Timing chain? If it's like a metallic rattle when cold for a short period could defn. be as it's a known issue with the OM651 diesel.

 

[Mymercedes220]

It's this noise. This isn't my car in the video but it's this exact loud rattly (I don't know how to describe it) noise !!!
Weird 3/4 second engine noise

 

[alexanderfoti]

Timing chain and/or the chain guides have fallen apart