I have an 05 Ex 6.0 diesel. Especially when still in warmup mode, if I get off the gas suddenly at around 30mph, I hear a noise for just about two seconds that is similar to the noise I'd expect if a tire was rubbing against the plastic inner fender wheel. Any idea what this could be? I have a .mov file with the noise, but don't know how to attach it here.

 

You can upload the video to youtube, then link it here.

Sounds like the turbo spooling down to me though. Excess pressure cycling through the system. Is the noise from the engine, or from something mechanical around the engine?