Normal Operation

WARNING: This page is about a different car, the 2006 Mercury Montego, 2006 Ford Freestyle, and 2006 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.

The engine cooling system functions to maintain engine temperatures during operation. Proper coolant flow through the engine, radiator and remainder of cooling system passages and components is essential to maintaining a proper engine temperature.

Engine coolant flows primarily from the engine to the radiator circuit and back to the coolant pump. From the coolant pump, coolant is sent through the engine block and cylinder heads. A separate circuit from the engine also feeds the heater core with coolant. The coolant pump is operated by engine rotation through a pulley which is driven by the accessory drive belt, a belt driven by a pulley attached to the camshaft, or a sprocket driven by the timing chain to circulate the coolant. The coolant thermostat is a control valve actuated by coolant temperature. When the thermostat is closed, coolant flow bypasses the radiator circuit and returns to the coolant pump. When the thermostat is opened, coolant is allowed to flow through the radiator circuit in order to transfer engine generated heat to the outside air.

Engine overheating generally occurs when there is a disruption in the ability to control either coolant flow at the proper rate, the inability to transfer heat from the engine through the coolant (including low coolant), or an inability to transfer engine generated heat to the outside air through the radiator.

For vehicle/engine specific information, refer to ENGINE COOLING in DESCRIPTION AND OPERATION .

DTC P0217 Engine Coolant (ECT) Over Temperature Condition
DTC P1285 Cylinder Head Over Temperature (CHT) Condition
DTC P1299 Cylinder Head Over Temperature Protection Active