Is there something wrong with the fan in my laptop?

I sent my laptop away to have the motherboard replaced.. which they later said wasn't necessary. When I got my laptop back, the fan inside whirs really loud and kicks on every 10 seconds and then fades back out. It also has a slight clicking sound, like when you put a playing card in your bike spokes. I had no issues with the fan before I sent it out and the sound is driving me nuts. Any suggestions? Is this normal?