Engine Cooling

2.0L:

2.5L:

Warning: Never remove the coolant expansion tank cap under any circumstances while the engine is operating. Failure to follow these instructions may result in damage to the cooling system or engine and/or personal injury. To avoid having scalding hot water or steam blow out of the cooling system, use extreme care when removing the coolant expansion tank cap from a hot cooling system. Wait until the engine has cooled, then wrap a thick cloth around the coolant expansion tank cap and turn it slowly until the pressure begins to release, step back while the pressure is released from the cooling system. When certain all the pressure has been released (still with a cloth) turn and remove the coolant expansion tank cap. Failure to follow these instructions may result in personal injury.

Warning: To avoid the possibility of personal injury or damage to the vehicle, do not operate the engine with the hood open until the fan blade has been examined for possible cracks and separation. Failure to follow this instruction may result in personal injury.

Warning: Disconnect the fan control wiring prior to performing any underhood service since the cooling fan motor could cycle if the ignition switch is left in the RUN position. Failure to follow this instruction may result in personal injury.

Note: The engine cooling system must be maintained with the correct concentration and type of anti-freeze solution to prevent corrosion damage.

The cooling system consists of the following:
^ Radiator
^ Coolant expansion tank cap
^ Thermostat
^ Water pump
^ Engine cooling fan motors and fan blades which are activated by the Powertrain Control Module (PCM) through two ISO relays in the battery junction box located near the battery in the engine compartment.
^ A separate coolant expansion tank located beside the radiator helps to maintain the correct volume of engine coolant.

The water pump is of a conventional design and is driven by the left-hand side intake camshaft through a drive belt on 2.5L vehicles and by the crankshaft pulley through the accessory drive belt on 2.0 L vehicles.
The thermostat:
^ Is located in the thermostat housing.
^ Allows rapid engine warm-up by restricting engine coolant flow at lower operating temperatures.
^ Assists in keeping the engine operating temperature within predetermined limits.

The engine cooling system operates as follows:
^ Coolant enters the radiator through the radiator inlet tank.
^ Coolant flows through the radiator tubes and is cooled by air passing over the cooling fins assisted by the fan control and the fan blades.
^ Coolant is then circulated from the radiator outlet tank where it mixes with coolant from the radiator coolant expansion tank and passes through the coolant thermostat housing.
^ Coolant then goes through the water pump and into the cylinder block and cylinder heads on the 2.5L vehicles and through the cylinder head and into the cylinder block on 2.0 L vehicles.
^ Coolant then flows out of the engine through the water crossover (2.5L engine) or through the coolant thermostat housing (2.0 L engine) to complete the circuit.

Refer to Specifications for the cooling system capacity.