At what temperature does the BMW 320 thermostat open?

[Christopher]

BMW 320's thermostat generally starts to open automatically when the temperature at the engine's coolant inlet reaches 103 degrees Celsius, without requiring DME control. Working principle of the thermostat: The commonly used thermostat is a wax-type thermostat. When the coolant temperature is below the specified value, the refined paraffin in the thermostat's temperature-sensing body remains solid, and the thermostat valve closes the passage between the engine and the radiator under the action of the spring. The coolant returns to the engine via the water pump, performing a small circulation within the engine. When the coolant temperature reaches the specified value, the paraffin begins to melt and gradually turns into a liquid, increasing in volume and compressing the rubber tube, causing it to contract. As the rubber tube contracts, it exerts an upward thrust on the push rod, which in turn exerts a downward counter-thrust on the valve, causing it to open. At this point, the coolant flows through the radiator and the thermostat valve, then returns to the engine via the water pump, performing a large circulation. Signs of a damaged thermostat: If coolant continues to flow out from the upper water chamber inlet pipe of the radiator when the engine starts cold, it indicates that the main valve of the thermostat cannot close. If there is no coolant flowing out from the upper water chamber inlet pipe of the radiator when the engine coolant temperature exceeds 70 degrees Celsius, it indicates that the main valve of the thermostat cannot open normally, and repair is needed at this time.