Squeak when engine is off!

[Bbrooks]

Hi, i went to look bat at 2002 172 today and it had a squeak coming from the engine bay when the key was in the on position (without the engine started), it sounded like something rotating.

The noise went away as soon as the engine was started.

Any ideas on what it might be?

Cheers, bbrooks.

 

[bloke]

throttle body, normal.