This engine thermostat regulates coolant flow to maintain the engine within its designed operating temperature range. It is installed in the cooling circuit between the engine block and the radiator; when closed, it restricts flow to speed warm-up, and as coolant temperature rises, it opens to allow full circulation. A stuck-closed thermostat causes rapid overheating, while a stuck-open unit prevents the engine from reaching operating temperature, leading to increased fuel consumption and reduced heater output. The original AGCO component is calibrated to the same opening temperature as the engine management system expects, so the electronic control unit receives accurate temperature signals for injection timing and emissions control. On reinstallation, replace the housing gasket and bleed air from the cooling system.