Genuine Volvo S80 Thermostat

Volvo S80 Thermostat Parts and Q&A

• Thermostat
  271664
  Q: What issues can arise from an aging thermostat, and How tots functionality be assessed and tested on Volvo S80?

  A:

  Older thermostats can gain slowness to react to variations in the temperature of the water supply, will have tendencies to stick in the open or the closed position which may cause problems such as slow or fast overheating. It would be worth checking the level of coolant before concluding that the thermostat is the source of some issue with the cooling system, since the leak or filling incorrectly may cause an air lock. Sometimes the thermostat may be unable to close and may be permanently open or may be absent; this may compromise the emissions and fuel economy since it takes long to warm up the engine. Assuming the engine is making its power, when the radiator top hose is cold, the thermostat may be stuck closed, and no coolant can leave the engine to flow to radiator. On the other hand, when the top hose is hot the coolant is running and this means that the thermostat is open. To evaluate the thermostat performance without the dismantling, turn the cold engine on and check the radiator top hose temperature and the coolant temperature gauge, the top hose is to be cold at the beginning and then readings are to be noticed when the thermostat opens and the temperature rises rapidly. In case the system fails to perform as expected, then the thermostat is to be removed and tested. Before starting the removal process, make the engine as cold as possible, drain the cooling system (partially) and remove the required pieces depending on the location of the thermostat (horizontal or vertical). To test it, one heats the water until the thermostat reaches its temperature mark and makes sure that it opens and closes correctly. In case the thermostat does not work properly, there is a necessity to change it. During refitting, a new sealing ring or gasket must be employed and all internal parts should be tightened before adding the top up the cooling system.