Heat shield fell off
 

Had a rattle when going over speed bumps which sounded like a heat shield. Took the car to a tyre and exhaust place near me and they lifted her and a tiny (between A5 - A4 paper size) heat shield had become loose and was resting on top of the exhaust. The tech got their pliers and bent/ripped it out before inspection if it can reattached :tuttut:. This heat shield protected the joint in the prop shaft. I don't think this will be a problem but I will have drop part, if not all, the exhaust to add a new shield.

How did that come loose???
Trying to remove them can be a pain when you intend to so how has this happened on its own?? Mystery.

¯\_(ツ)_/¯ mystery to me also! Maybe I should get her lifted again and inspect the centre support bearing as that's above the shield.

http://www.blauparts.com/assets/audi...driveshaft.gif

Heat shields are generally fixed with a pretty poor type of rivet that are prone to failure. Heat shields are quite cheap but fitting will involve serious labour for access, might best left alone for now.

One of my Heat shields had worked itself loose too. It hadn't started rattling or anything, but the fastener wasn't holding it in place anymore. It's getting changed as a precaution while they fit the OEM exhaust.

I'd have a good snoop around the affected area, just in case something else caused it. If there's nothing immediately apparent, replace it and forget it.