Engine Cooling System & Automatic Transmission Cooling System: Overview Dodge Avenger II

Scheme 15

The cooling system consists of an engine cooling module, thermostat, non-pressure coolant recovery container (2.0L/2.4L) or pressurized coolant recovery container (2.7L/3.5L/2.0L Diesel), coolant, hoses, and a water pump to circulate the coolant. The engine cooling module consists of a radiator, electric fans, shroud, transmission oil cooler, and air conditioning condenser.

Scheme 16

The primary purpose of a cooling system is to maintain engine temperature in a range that will provide satisfactory engine performance and emission levels under all expected driving conditions.

Scheme 17

The cooling system also provides hot water (coolant) for heater performance.

OPERATION

Coolant flows through the engine block absorbing the heat from the engine, then flows to the radiator where the cooling fins in the radiator transfers the heat from the coolant to the atmosphere. During cold weather the ethylene-glycol or coolant prevents water present in the cooling system from freezing within temperatures indicated by mixture ratio of coolant to water.

2.0L/2.4L ENGINE - The block heater element is submerged in the cooling system's coolant. When electrical power (110 volt AC) is applied to the element, it creates heat. This heat is transferred to the engine coolant. This provides easier engine starting and faster warm-up when vehicle is operated in areas having extremely low temperatures.

2.7L/3.5L ENGINE - When power is applied (110 volt AC) to the block heater, the heating element transfers heat through the aluminum engine block and into the coolant without directly penetrating the cooling system.

The ECT sensor provides an input to the PCM. As temperature increases, resistance of the sensor decreases. As coolant temperature varies, the ECT sensor resistance changes resulting in a different voltage value at the PCM ECT sensor signal circuit. The ECT sensor provides input for various PCM operations. The PCM uses the input to control air-fuel mixture, timing, and radiator fan on/off times. The PCM uses ECT sensor input to send messages over the CAN bus to various modules for other functions such as temperature gauge and AC operation.

Scheme 18

1. Disconnect negative battery cable.
2. Partially drain cooling system below level of ECT Sensor.
3. Disconnect ECT Sensor electrical connector.
4. Remove ECT Sensor.

Scheme 19

1. Disconnect negative battery cable.
2. Partially drain cooling system below level of ECT Sensor (1).
3. Disconnect ECT Sensor electrical connector.
4. Remove ECT Sensor (1).

Scheme 20

1. Disconnect negative battery cable.
2. Remove engine cover. Refer to «REMOVAL»(ref-305761-S28982146422008120200000) . Refer to «REMOVAL»(ref-305762-S42490331882008120200000) . Refer to «REMOVAL»(ref-305763-S31788323032008120200000) .
3. Partially drain coolant system below pressurized coolant recovery container. See «STANDARD PROCEDURE»(ref-305776-S22576414292008120200000) .
4. Unplug coolant temperature sensor electrical connector. NOTE: Capture any residual coolant that may flow.
5. Remove coolant temperature sensor (5).

Scheme 21

1. Disconnect negative battery cable.
2. Partially drain cooling system. See «STANDARD PROCEDURE»(ref-305776-S22576414292008120200000) .
3. Disconnect the electrical connector (2).
4. Remove engine coolant sensor (1) from coolant outlet tube (3).

Scheme 22

1. Disconnect negative battery cable.
2. Partially drain cooling system. See «STANDARD PROCEDURE»(ref-305776-S22576414292008120200000) .
3. With the engine cold, disconnect coolant sensor electrical connector.
4. Remove sensor (2).

Scheme 23

1. Install ECT Sensor (1). Make sure coolant sensor is locked in place
2. Reconnect ECT Sensor electrical connector.
3. Fill cooling system. See «STANDARD PROCEDURE»(ref-305776-S22576414292008120200000) .
4. Connect negative battery cable.

Scheme 24

1. Install ECT Sensor. Tighten sensor to 19 N.m (168 in. lbs.).
2. Reconnect ECT Sensor electrical connector.
3. Fill cooling system. See «STANDARD PROCEDURE»(ref-305776-S22576414292008120200000) .
4. Connect negative battery cable.

The pressure cap allows the cooling system to operate at higher than atmospheric pressure. The higher pressure raises the coolant boiling point; this allows increased radiator cooling capacity.

The gasket in the cap seals the filler neck, so that vacuum can be maintained, allowing coolant to be drawn back into the cooling system from the reserve container.

Scheme 25

Dip the pressure cap in water. Clean any deposits off the vent valve or its seat and apply cap to end of the Pressure Cap Test Adapter that is included with the Cooling System Tester 7700. Working the plunger, bring the pressure to 104 kPa (15 psi) on the gauge. If the pressure cap fails to hold pressure of at least 97 kPa (14 psi), replace the pressure cap.

If the pressure cap tests properly while positioned on Cooling System Tester but will not hold pressure or vacuum when positioned on the filler neck. Inspect the filler neck and cap top gasket for irregularities that may prevent the cap from sealing properly.

The radiator fans are controlled by the Powertrain Control Module (PCM) which energizes a high speed or low speed fan relay. The electric motor drives the cooling fan to produce air flow across the radiator fins.

DESCRIPTION

An external oil-to-air type automatic transmission oil cooler is mounted to the front of the radiator and is integral to the A/C condenser. The six upper tubes are used for transaxle oil cooling, and the remaining tubes below are for the A/C system.

The cooler uses tubes and rubber hoses to feed oil to and from the automatic transaxle. The replaceable inlet and outlet tubes use quick-connect type fittings. The trans oil cooler is replaced with the A/C condenser.

Scheme 26

The oil flows from the transmission to the oil-to-air cooler. Heat is then transferred into the air.