[Kryptek49]

Hi all,

My 2006 320i has a rattle on cold start which appears when you rev the engine, the problem appears to be somewhere along the exhaust but I haven't been able to pin point it as of yet.

While inspecting the exhaust I noticed these exhaust nuts:

View post on imgur.com

From my googling, the bolts have a flat back and splines so they you don't need to secure the back when removing/installing the bolts.

My query is with the front of the bolts, the nuts seem almost non existent? I don't know if they are just so rusted that they've completely disintegrated?

The left & right nut seem pretty bad and the middle one is not even there?

Anyone have any thoughts on this? It seems odd that there is nothing left of the nuts?