Thermostat: Description and Operation

OPERATION

The electronic three disc thermostat has four operating modes.

FULL THROTTLING





With a cold start, the thermostat is not actuated and the heating circuit is closed. Stationary coolant heats very quickly. the heat is conducted to the engine oil over the heat exchanger on the front of the engine.

From approximately 70°C (150°F) coolant temperature or 45°C (113°F), (with enabled temperature control), a transfer takes place from full throttling to short circuit operation.

SHORT CIRCUIT OPERATION





The short circuit operation circulates the coolant through the block to warm up the engine quickly.

MIXED OPERATION





The temperature control is enabled when the coolant temperature reaches 98°C (208°F) after starting. It becomes active immediately at outside temperatures above 28°C (82°F).

The thermostat controls with partial load to an increased coolant temperature of 100°C (212°F).

To prevent critical temperatures, the range of increased coolant temperature is lowered under the following conditions to 90°C (194°F) (with outside temperature below 11°C (51°F) or to 80°C (176°F) (with outside temperature above 11°C (51°F).

- High engine load
- Intake air temperature above 38°C (100°F)

RADIATOR OPERATION





The thermostat is continuously actuated in radiator operation. Above 105°C (221° F), the thermostat is always fully open independently of the actuation.