Checking the thermostat

Fig 1: Engine Start Verification

Courtesy of VOLVO CARS OF NORTH AMERICA.

• Start the engine. Run the engine until the engine coolant temperature (ECT) reaches approximately 100°C
• Activate the engine cooling fan (FC) with the engine running
• Wait approximately 90 seconds and then shut-off the engine cooling fan (FC).

  Read off the engine coolant temperature (ECT). If it is 85°C or lower when the fan stops, the thermostat is defective.

  Fig 2: Identifying VCT2000 Diagnostic Tool

  Courtesy of VOLVO CARS OF NORTH AMERICA.

Is the engine coolant temperature (ECT) 85°C or lower? 

• YES 

  Refer to Replacing thermostat 

• NO 

  Refer to Information