Idle wheels on 1997 Mercury Mountaineer

I think the idle wheel is making a winding sound. If its bad how much to replace

2 answers
generally it is the Belt Tensioner Idler assembly. It usually take about 1/2 hour to replace and the part can run from $100 to $150 if it is a factory part.
Where's the idle wheel located on a 2004 Mercury Mountaineer. 4.6 litter V8 AWD. Is it located in the front of the motor?