Have you checked the drive belts? According to Bentley:
"Replacement of V-belts (a.k.a. serpentine) is recommended every 4 years. Inspect belts with engine off. Twist belt to inspect sidewalls and bottom. Belt structural damage, glazed or shiny sidewalls, caused by loose belt, or separation are all reasons for replacement."
You may also have to replace the idler pulley, hydraulic belt tensioner, and tensioner roller. All pretty cheap fixes and rather simple to do yourself.