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Frequently asked questions about cars and motorcycles

Check Thermostat Operation

Model: BMW Serie 5 E39 - Years 1995-2003
Part: Thermostat

If the temperature gauge needle tends to exceed the center position, indicating an increase in temperature, there can be several causes. Before assuming a failure of the head gasket, check the actual water temperature in the reservoir with a thermometer: if this value is close to 194°F, it is possible that the bulb has malfunctioned, sending an incorrect value to the gauge. If the temperature exceeds 194°F, there may be an issue with the thermostat valve not opening properly or with the circulation pump. You will need to investigate further.

Updated on 11 February 2026 by ScegliAuto

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