2000 Ford Windstar, 3.8l v6 - Odd squeal and hesitation and general "bad" noise detected while driving.

I'm not 100% sure if it was the tensioner or idler pulley, but they were cheap enough parts to get and put in. 

If you have the $250-$300 to pay to have it done, go ahead, this was about a two hour job and $75.00 for the two parts.

The idler pulley of course did not have enough clearance between the frame pulley to remove the bolt:, so go:

• loosen the motor mounts
• find a 6 foot breaker bar (i used a chain link fence post)
• Insert breaker bar between fram and engine (solid peice next to water pump)
• Gently move the engine the 1/8 of an inch and remove pulley with bolt
• repeat in reverse for re-installation, don't forget to tightent he motor mounts

The tensioner and pulley is sold as a unit.  This is a difficult task, due to the limited space.  3 Bolts.  the one on the bottom is easy, the two on top were quite difficult.  10mm Bolts, top 2 require the smallest ratchet you can find; I have a 1/4" set, so it worked nicely.  The smaller your hands the easier the job will be, I found it easier to get the top two bolts, from the top of the engine for both removal and installation.

Hopefully this solves the problem...