330 w/ M sport package rattle when turning off engine

[Greg330]

Good day folks, I need some of your input...
I bought a 2005 330 "M sport package", (Parkview BMW dealer cert. pre-owned) it had 51K when I bought it in Dec. 07; it is now at 70K...Oil changes are made regularly and drives fine and shifting seems fine. Extd warranty still valid.
Just lately, I've notice that when I turn the car off, I hear a subtle "rattle" from the engine as the engine dies. Although it is not audible or noticeable when my clutch pedal is press down.
I went to the dealer and the service manager says "you have nothing to worry about, what you are hearing is the secondary air pump. Its an emission device so, its common". The car was never hoist up nor looked at by the technician.
Is the serv mgr right? Any similar experiences out there? Should I get a 2nd opinion?

[marti5]

Hard to say what it is without hearing it, I would get a 2nd opinion.

[Greg330]

Heading for a 2nd op..Thx Marti5....

[skim111]

How'd it go?
Think I know what you're hearing..