PT Cruiser L4-2.4L Turbo VIN G (2004)
The thermostat is located on the front of the engine (radiator side) in the thermostat housing/ coolant outlet connector. The thermostat has an air bleed
vent located on its flange. The air bleed vent and the locator dimple on thermostat seal provide for proper positioning of thermostat in outlet
connector. A cooling system air bleed valve is located in thermostat housing to assist in air removal when filling the cooling system.
OPERATION
The engine cooling thermostat is a wax pellet driven, reverse poppet choke type. The thermostat is designed to provide the fastest warm up possible by
preventing leakage through it and to guarantee a minimum engine operating temperature of 88 to 93 °C (192 to 199 °F). The thermostat will also
auto- automatically reach wide open so it will not restrict flow to the radiator as the temperature of the coolant rises in hot weather to around 104 °C
(220 °F). Above this temperature the coolant temperature is controlled by the radiator, fan, and ambient temperature, not the thermostat.
The thermostat is operated by a wax filled chamber (pellet) which is sealed. When coolant reaches a predetermined temperature, the wax expands
enough to overcome the closing spring and water pump pressure, which forces the thermostat to open. Coolant leakage into the wax pellet will cause a
thermostat to fail in the open position.
Do not attempt to free-up a stuck open thermostat.
If the thermostat is stuck open or allows coolant leakage through it, the engine will not operate at the proper temperature for obtaining engine fuel
efficiency, performance and emissions levels. If this condition occurs, a diagnostic trouble code will be set and a MIL light will be turned on.
