Front-End Problem

I have a 1999 Diamonte with around 90K miles. When I am at a full stop and turn the wheel significantly in any direction, I get a pop-pop-poping sound. For example, when parking. It only seems to occur when I am begin moving from a complete or near-complete stop. Does anyone know what this is? I had the front end checked out at a local garage but they were unable to diagnose the problem, although they had not trouble duplicating the symtoms. They suggested that I go the dealer, as this may be a recurring problem specific to this model. Any help would be appreciated. Thanks in advance!