Genuine 2009 Volvo S40 Thermostat

2009 Volvo S40 Thermostat Parts and Q&A

• Q: How does an aging thermostat affect water temperature regulation and what steps should be taken to assess and replace it on 2009 Volvo S40?

  A: As thermostats age, they may react slowly to water temperature changes, which could result in slow warm up or overheating. Before assuming a thermostat problem, do a coolant check for leaks. Testing includes monitoring the temperature of the hose and making sure that it works correctly by heating water. Replace faulty thermostats, and carefully reassemble the cooling system.