Squealing sound on startup - 2001 x5 3.0i

[Werewolf]

Hi all,

I've noticed a high pitch squealing (mechanical not pig-like) when I start up the engine. It is most noticeable towards the end of cranking (engine starts, revs goes down, squealing). It lasts for a couple of seconds at most.

Is this an issue? Should I be worried? I went poking around with a flashlight, thinking it was a belt issue (looking at the accessory belt and couldn't see any cracking).

Any ideas what it could be?

Thanks in advance!