Engine Cooling System & Automatic Transmission Cooling System: Overview Dodge Journey I

Scheme 12

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

Scheme 13

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 14

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

Scheme 15

Scheme 16

The water pump draws coolant from the radiator and delivers it to the engine block. The coolant travels through the engine block into the cylinder head. Coolant exits the engine at the thermostat. If the coolant temperature is less than 87°C (189°F) the thermostat directs all of the coolant back to the water pump. If the coolant temperature is between 87°C (189°F) and 102°C (216°F) the thermostat is in the mix mode and directs the coolant to the radiator and the water pump. If the coolant is greater than 102°C (216°F), the thermostat directs all of the coolant to the radiator.

The thermostat also feeds excess coolant and bleeds air from the system through a hose leading to the coolant reservoir. The reservoir returns coolant to the inlet side of the water pump. A port and hose at the rear of the engine block provides coolant to the heater core. This coolant is returned to the engine at the intake side of the water pump.

The oil cooler receives coolant directly from the engine block. A hose returns this coolant to the inlet side of the water pump.

REVERSE FLUSHING DESCRIPTION

Reverse flushing of the cooling system is the forcing of water through the cooling system. This is done using air pressure in the opposite direction of normal coolant flow. It is usually only necessary with very dirty systems with evidence of partial plugging.

OPERATION

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 17

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 Adaptor 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.

DESCRIPTION

The radiator fan module includes a support shroud (2) with an electrically driven motor (1) with a fan blade. The radiator fan module is attached to the radiator.

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.

When power is applied (110 volt A.C.) to the block heater, the heating element transfers heat through the aluminum engine block and into the coolant without directly penetrating the cooling system.

All vehicles are equipped with a cross flow type radiator with plastic side tanks.

Plastic tanks, while stronger than brass, are subject to damage by impact, such as from tools or wrenches. Handle radiator with care.

Scheme 18

Scheme 19

1. Disconnect negative cable from auxiliary jumper terminal.
2. Remove engine cover.
3. Remove air box assembly. Refer to «Engine/Air Intake System/BODY, Air Cleaner - Removal»(ref-353574-S13740738892010011200000) .
4. Recover A/C system. Refer to «Heating and Air Conditioning/Plumbing - Standard Procedure»(ref-353571-S22405082752010011200000) . WARNING: Do not remove pressure cap or any hose with the system hot and under pressure because serious burns from coolant can occur.
5. Drain cooling system. See «Standard Procedure»(ref-353584-S11330501202010011200000) .
6. Remove the grille.
7. Remove under belly pan (if equipped).
8. Remove front bottom splash shield (if equipped).
9. Remove upper and lower radiator hoses at radiator.
10. Disconnect radiator fan electrical connector (1). 1 - A/C LINE 2 - SUPPORT BRACKET
11. Separate radiator cooling fans from radiator.
12. Disconnect A/C line (1) at condenser/cooler.
13. Remove transmission oil cooler tubes support bracket at left side of radiator (if equipped) (2). CAUTION: Plastic tanks, while stronger than brass are subject to damage by impact, such as wrenches.
14. Remove the two Torx screws located on the upper radiator support that hold the upper radiator mounting brackets.
15. Tilt the top of the radiator rearward so the mounting brackets slide out of the upper core support.
16. Remove radiator/condenser assembly by lifting the assembly out of the vehicle between the engine and the core support.
17. Separate the A/C condenser from the radiator.

There are two Engine Coolant Temperature (ECT) Sensors. One of the sensors threads into the block. The other sensor is located at the top of the coolant adapter housing. The ECT Sensor is a negative thermal coefficient sensor.

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 20

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 21

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 22

1. Partially drain cooling system below level of ECT sensor.
2. Remove upper intake manifold. Refer to «Engine/Manifolds/MANIFOLD, Intake - Removal»(ref-353574-S17562254772010011200000) .
3. Disconnect ECT sensor electrical connector.
4. Remove ECT sensor.

Scheme 23

1. Disconnect negative battery cable.
2. Partially drain cooling system. See «Standard Procedure»(ref-353584-S11330501202010011200000) .
3. Disconnect coolant sensor electrical connector.
4. Remove coolant temperature sensor.

Scheme 24

1. Disconnect negative battery cable.
2. Remove engine cover. Refer to «Engine - Removal»(ref-353574-S23427753412010011200000) .
3. Partially drain coolant system below pressurized coolant recovery container. See «Standard Procedure»(ref-353584-S11330501202010011200000) .
4. Unplug coolant temperature sensor electrical connector. NOTE: Capture any residual coolant that may flow.
5. Remove coolant temperature sensor (5).

Scheme 25

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-353584-S11330501202010011200000) .
4. Connect negative battery cable.

Scheme 26

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-353584-S11330501202010011200000) .
4. Connect negative battery cable.

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 also will automatically reach wide open so it will not restrict flow to the radiator as 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 oil flows from the transmission to the oil-to-air cooler. Heat is then transferred into the air.