850/V70 thermostat replacement

1. Lift the front of the car (on ramps or with a jack). 2. Drain 3–5 liters of coolant from the driver's side radiator drain plug. 3. Disconnect the upper water hose from the thermostat housing. 4. Open 2 x T40 Torx bolts (1/4" wrench + extension + socket). 5. Remove the old thermostat and install the new one with a gasket. 6. Reassemble in reverse order.

The typical thermostat opening temperature is 90 °C (Wahler thermostat). If the car heats up slowly or the heating doesn't work properly, the thermostat is likely stuck in the open position.

The plastic drain plug (about €2.65) breaks easily, so handle it carefully.