Loud rattling noise when bus idles.

[pmoc_2001]

I have noticed a loud rattling noise when my bus first starts.
I think I have found the cause. I think it may be a spring joint in the exhaust that rattles when the diesel is cold and idling. The noise is less prominent after the engine has been driven for about 20 mins and returned to idle.
Is this very loud rattle common or do I need to investigate further.

[kevtherev]

I see that Brickwerks' new exhaust section seems to have a braided section rather than a spring.

May be it was made that way because of the issue you describe?