http://www.shopjimmy.com/samsung-hls6186wx/xaa for example finds a color wheel. I do not diagnose devices (controls, PCs and more) over a forum. I've yet to see any tech or engineer do that but since it does make a whirring sound and this does indeed have moving parts you can guess that the fault is that part or nearby.

I don't want to upset you but this area is one that is not user serviceable and not one where you can write "replace part #1."
Bob