Squeaking noise with cold engine...

[Sharkster]

When I turn on my H3 in the morning (after it stood still all night), I can hear a high frequency squeaking noise from the engine, going like "squeak-squeak-squeak-squeak..."

After approx. 3-5 minutes the noise goes away and doesn't return no matter how often I start the engine on that same day again. So it only appears, when the engine has been off for at least 12 hours.

It kinda sounds like it is coming from the v-belt... Overall it doesn't sound too alarming so I guess it's nothing really serious... I just would like to find out where it's coming from. Has anyone else experienced this?