I sometimes get a brief shrill whining noise when starting my 1998 Mercury Villager. What should I do? It just started a couple months ago. The car seems to be running fine otherwise.

I sometimes get a brief shrill whining noise when starting my 1998 Mercury Villager. What should I do? It just started a couple months ago. The car seems to be running fine otherwise.
Is the noise while the engine is still turning over, or immediately after is starts?
During the cranking is likely the starter and how it meshes with the flywheel.
During start-up idle is likely a slipping drive belt, or possibly a vacuum leak.
The drive belt could be stretched beyond normal or the belt tensioner may be weak or seized.