If the loud clicking noise is coming from near the top of the machine near the detergent drawer it is most likely to be the water diverter. This part diverts the water flowing into the machine into the detergent or fabric softener sections of the drawer. If it is broken the machine will not fill. The part has a series of plastic cogs, if they are broken or missing any teeth you get that weird click,click sound when the machine tries to fill. (You can see the area if you take the top off the machine). Given that they are plastic - you'll probably need to order a new water diverter. In the short term you can get the machine to fill and run by removing one of the cogs until you get a replacement part. The machine will fill and run without the cog BUT you won't get any water flowing through the detergent drawer, so you'll have to place the soap in the drum. The part itself is quite easily replaced.
Jacqui, March 2008