Checking the Thermostat (BMW X5 E53)

The thermostat, given its non-separable design, must be tested in the following order. Install the thermostat body on a container with water so that the thermostat itself is immersed in the liquid. Heat the thermostat, recording the temperature, while it should not touch the walls of the container.

At a temperature of about 88°C, the thermostat valve begins to open. Continue heating the water at a rate of about one degree per minute and monitor the opening of the valve. Record the temperature of full valve opening. Stop heating and record the temperature of full valve closing. Compare the results with the technical data for the thermostat.