Light sqeel noise - T350

[DanR100]

Hadnt used the car for a week and started her up and all was fine although i could hear a light sqeeling noise similar to a loose fan belt but no where as noisy, i opened the bonnet and the sound came from the top front of the engine where a pulley and belt is on, after 30 seconds of engine running the noise vanished. The car is kept in an open garage, what could cause this noise??

[Hollowpockets]

It was the alternator belt on my car, just needed tensioned up a bit more.