Checking The Tensioner And Idler Pulleys
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2006 Volvo S80, 2005 Volvo S80, 2004 Volvo S80, 2003 Volvo S80, and 2002 Volvo S80. However, it is still accessible from the selected car via links, so may be relevant.
Spin the pulleys and listen for noise from the bearings. Check that the pulley surfaces to the belt are clean and smooth.
Check the tension pulley lever and mounting. The tensioner pulley lever, torque 30 Nm . The idler pulley, tightening torque 25 Nm .