Thermostat sticking or failing
Symptoms
Engine runs cold (heater barely works, fuel economy drops) or overheats. Temperature gauge behaves erratically.
Cause
Thermostats wear out or get stuck open/closed. Some previous owners fit the wrong temperature unit (82°C vs 92°C). The 240 runs best at 92°C, it reduces piston slap and improves fuel economy.
Fix
Replace the thermostat with a 92°C unit (genuine Volvo or quality aftermarket).
Make sure the jiggle pin (small brass valve) is at 12 o'clock when you install it, this lets air bleed out.
Refill the system slowly to avoid air pockets.
Know something we don't?
Owned a Volvo 242 / 244 / 245? Share your experience with this issue. What worked, what didn't, costs, tips. Help the community.
Submit an update