Valve Clearance, Setting / Adjusting: Check
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.
Check the level in the expansion tank and the brake fluid reservoir.
Top up if necessary.
Test drive the engine until the thermostat opens and check for any leakage.