Hi,
The lens assembly moves backwards and forwards on slim metal rods on either side.
Could be that the original lubricant has all dried up and now the lens is getting stuck in one or more places.
When the lens assembly gets stuck in one position it makes a sort of whirring noise.
This happened to my PS2 , I used a very small amount of WD40, use a cotton bud or something like a paper clip to drip a very small amount all along each of the rods.
Don't try to spray the WD40 onto the rods as it will go everywhere and possibley onto the electrics which you do not want.
Also you could check out this detailed PS2 Repair website :
http://www.tweak3d.net/articles/ps2repair/
Jim, February 2006
