Turbo Vibration?

[arizonabob]

The exhaust system on my 06' 6.0 vibrates sometimes to the point of making a loud buzzing sound. I have been under my truck pushing and pulling on all connection points and hangers, but can't find anything loose. Can the vibration be coming from the turbo and resonating through the exhaust?
Thanks,
Bob

[arizonabob]

PS I only notice the vibration at idle.

[Powermoon]

Have you checked the clamp that connects the downpipe to the turbo? I've never heard of it coming loose but it might be possible. Also, I know that when I first installed my exhaust that at a certain rpms my downpipe would make contact with the firewall and make an awful buzzing sound. This would happen when moving, but when not in motion, it wasn't touching anything. I loosened the downpipe and put a wood 2x4 block between the downpipe and firewall where I thought it was making contact and then tightened the clamp up. Removed the block and the buzzing went away and haven't heard it since. Not sure if this helps. Sorry, started typing before I saw your last post