Laptop fan noisy on startup

Recently my IBM ThinkPad T43 (running Windows XP SP3) has been making a loud whirring noise when booting and the noise seems to be coming from the fan. It didn't used to do this and doesn't it every time but does do it most times. After a short time it stops and only once has the noise recurred later during the same session. There have been no other problems or error messages.

I've read that ThinkPad fans are notoriously noisy so I'm not entirely sure whether I have a problem or not. On the one hand the noise is new but on the other it doesn't seem to be having any adverse effects.

I haven't yet opened up the casing to check for loose parts etc.

Does it sound like I need to replace the fan, should I open it up and look for visual clues or is it just a noisy fan and nothing to worry about?

Thanks

via Bleeping Computer Last 20 Posts http://www.bleepingcomputer.com/forums/t/510525/laptop-fan-noisy-on-startup/