[TheBobmanNH]

Hi, I have a new to me E85 Z4 convertible (89k miles), and it has a bit of a whine from the engine under acceleration / load. Brought it to a well-reviewed local shop and they "couldn't hear it," which seems crazy -- it's not loud but it's definitely noticeable, even to my damaged 40-something ears.

While I know a general "there's a whine on acceleration" is way too vague to diagnose on the Internet, are there any common things I can look at? It's tough because it won't do it at idle or revving in neutral so I can't just stick my head under the hood.

It's a 5-speed, does it in any gear. Increases in pitch a bit with engine RPMs but not much.

The noise doesn't "bother" me per se, I just don't want to find out it's something serious after it's too late.

Thanks!