General description
The engine cooling system maintains the engine temperature at an efficient level in all engine operating modes.
When the engine is cold, the cooling system cools the engine slowly or not at all. This slow cooling allows the engine to warm up quickly.
The cooling system includes the radiator and recirculation subsystem, cooling fans, thermostat and housing, water pump and water pump drive belt. Timing belts drive the water pump.
For the cooling system to function, all components must work properly. The water pump draws coolant from the radiator. Coolant circulates through water jackets in the cylinder block, intake manifold and cylinder head. When the coolant temperature reaches the operating temperature of the thermostat, the thermostat opens. The coolant then returns to the radiator where it cools. The system directs some of the coolant through the hoses to the heater heat exchanger. This ensures heating and defrosting. The expansion tank is connected to a radiator to receive coolant displaced by high temperatures.
The expansion tank ensures the correct coolant level.
The cooling system of this engine does not have a radiator cap or filler pipe. Coolant is added to the system through the expansion tank.
Radiator
This car has an aluminum plate-pipe radiator with lightweight design. Plastic tanks are installed on the right and left side of the radiator heat exchanger.
On vehicles with an automatic transaxle, the transmission fluid cooling lines run through the left radiator tank. The drain plug is on this radiator. To empty the cooling system, open the drain plug.
Expansion tank
The expansion tank is a plastic container similar to the windshield washer reservoir.
The expansion tank is connected to the radiator by a hose, and the engine cooling system is connected to another hose. When the vehicle is running, the engine coolant heats up and expands. Some of the engine coolant displaced by this expansion flows from the radiator and engine into the expansion tank. The air in the radiator and engine is forced out into the expansion tank.
When the engine is stopped, the coolant cools and contracts. The displaced engine coolant is returned back to the radiator and engine. This maintains the correct level of coolant in the radiator and increases cooling efficiency.
Set the coolant level between the MIN and MAX marks on the expansion tank when the system is cold.
Coolant pump; Water pump
The belt driven centrifugal coolant pump consists of an impeller, a drive shaft and a belt pulley. The coolant pump is mounted on the front of the transverse engine and is driven by the timing belt.
The impeller is on a sealed bearing. The coolant pump is serviced as a single unit and therefore cannot be dismantled.
Thermostat
The wax thermostat controls the flow of engine coolant through the engine cooling system. The thermostat is mounted on the thermostat housing at the front of the cylinder head.
The thermostat stops the flow of coolant from the engine to the radiator to allow rapid heating and control of the coolant temperature. The thermostat remains closed at low coolant temperatures, preventing engine coolant from circulating through the radiator. At this time, the engine coolant circulates only through the heat exchanger for fast and even heating.
After the engine warms up, the thermostat opens. This allows the engine coolant to flow through the radiator where the heat is dissipated through the radiator. Opening and closing the thermostat allows engine coolant to flow into the radiator and keep the engine temperature within the operating range.
The wax ball in the thermostat is hermetically sealed in a metal shell. The wax element of the thermostat expands when heated and contracts when cooled.
When the vehicle is running and the engine warms up, the temperature of the coolant increases. When the coolant temperature reaches the set temperature, the wax element of the thermostat expands and presses against the metal shell, causing the valve to open. This allows engine coolant to flow through the engine cooling system and cool the engine. As the wax ball cools, its constriction allows the spring to close the valve.
The thermostat starts to open at 87°C (189°F) and fully opens at 102°C (216°F). Thermostat closes at 86°C (187°F).
Cooling fan
Attention! To prevent injury, keep hands, tools, and clothing away from the cooling fan. The fan is electrical and can turn on whether the engine is running or not.
Attention! If the fan blade is bent or damaged in any way, do not attempt to repair or reuse the damaged part. A bent or damaged fan must be replaced with a new one. Failure to do so may result in injury.
The cooling fans are installed behind the radiator in the engine compartment. The cooling system of this vehicle has two cooling fans - a main fan and an auxiliary fan. Electric fans of the cooling system increase the air flow through the radiator fins and through the condenser on vehicles equipped with air conditioning. This allows faster cooling at idle or low speeds.
Vehicles with and without air conditioning have two fans in the shroud. Main fan size - 340 mm (13.4 inches) in diameter with five blades, and the auxiliary - 320 mm (12.6 inches) in diameter with seven blades. They contribute to the passage of air through the radiator and condenser. Two fan motors attached to the center of each fan on the shroud assembly drive both fans.
When the air conditioner is off or for a model without air conditioning
- The cooling fans are driven by the ECM through the series/parallel cooling fan relay.
- The ECM turns on the cooling fans at low speeds if the coolant temperature reaches 96°C (205°F), and at high speeds if the coolant temperature reaches 100°C (212°F).
- ECM switches cooling fans from high to low speed at 94°C (201°F) and turns them off at 90°C (194°F).
A/C on
- The ECM turns the fans on slowly when the A/C system is on. The ECM switches to a fast fan speed when the coolant temperature reaches 118°C (244°F) or when the high pressure side of the air conditioner reaches 1760 kPa (255 psi inch).
- Cooling fans return to low speed when coolant temperature reaches 115°C (239°F) and when the high pressure side of the air conditioner reaches 1347 kPa (195 psi inch).