on my 5 series:
I was having a small rough idle (just on idle).
I was curiously looking around the engine bay and noticed something was off, and my EGR air pump was basically off its mounting bracket and somewhat dangling. Luckily it never hit the floor and get hit or anything.
Ordered some new rubber mounts to attach the air pump to its bracket (3 small mounts @ $21 each - ouch!). I needed a new EGR hose too, as the old one was basically disintegrated.
issue is fixed, and running smoothly for now
Also my odometer rolled past 200,000kms.