Engine Cooling System: Other Dodge Durango III

COOLING SYSTEM COMPONENTS

The cooling system consists of

1. Electric cooling fan
2. Radiator
3. A coolant recovery system
4. Thermostat
5. Water pump
6. Radiator pressure cap
7. Coolant
8. Water pump
9. Hoses and hose clamps

RECENT SERVICE OR ACCIDENT REPAIR

Determine if any recent service has been performed on vehicle that may effect cooling system. This may be

1. Engine adjustments (incorrect timing)
2. Slipping engine accessory drive belt(s)
3. Brakes (possibly dragging)
4. Changed parts. Incorrect water pump, or pump rotating in wrong direction due to belt not correctly routed
5. Reconditioned radiator or cooling system refilling (possibly under filled or air trapped in system).

Note. If investigation reveals none of the previous items as a cause for an engine overheating complaint, refer to following Cooling System Diagnosis charts below.

These charts are to be used as a quick-reference only. Refer to the group text for information.

COOLING SYSTEM DIAGNOSIS

Scheme 19

A leak detection additive is available through the parts department that can be added to cooling system. The additive is highly visible under ultraviolet light (black light). Pour one ounce of additive into cooling system. Place heater control unit in HEAT position. Start and operate engine until radiator upper hose is warm to touch. Aim the commercially available black light tool at components to be checked. If leaks are present, black light will cause additive to glow a bright green color.

The black light can be used in conjunction with a pressure tester to determine if any external leaks exist.

Scheme 20

Scheme 21

The engine should be at normal operating temperature. Recheck the system cold if cause of coolant loss is not located during the warm engine examination.

Carefully remove radiator pressure cap from filler neck and check coolant level. Push down on cap to disengage it from stop tabs. Wipe inside of filler neck and examine lower inside sealing seat for nicks, cracks, paint, dirt and solder residue. Inspect radiator-to- reserve/overflow tank hose for internal obstructions. Insert a wire through the hose to be sure it is not obstructed.

Inspect cams on outside of filler neck. If cams are damaged, seating of pressure cap valve and tester seal will be affected.

Attach pressure tester ((special tool #7700, Tester, Cooling System) or an equivalent) to radiator filler neck.

Operate tester pump to apply 103.4 kPa (15 psi) pressure to system. If hoses enlarge excessively or bulges while testing, replace as necessary. Observe gauge pointer and determine condition of cooling system according to following criteria

Holds Steady: If pointer remains steady for two minutes, serious coolant leaks are not present in system. However, there could be an internal leak that does not appear with normal system test pressure. If it is certain that coolant is being lost and leaks cannot be detected, inspect for interior leakage or perform Internal Leakage Test.

Drops Slowly: Indicates a small leak or seepage is occurring. Examine all connections for seepage or slight leakage with a flashlight. Inspect radiator, hoses, gasket edges and heater. Seal small leak holes with a Sealer Lubricant (or equivalent). Repair leak holes and inspect system again with pressure applied.

Drops Quickly: Indicates that serious leakage is occurring. Examine system for external leakage. If leaks are not visible, inspect for internal leakage. Large radiator leak holes should be repaired by a reputable radiator repair shop.

COOLING SYSTEM DEAERATION

As the engine operates, any air trapped in cooling system gathers under the radiator cap. The next time the engine is operated, thermal expansion of coolant will push any trapped air past radiator cap into the coolant reserve/overflow tank. Here it escapes to the atmosphere into the tank. When the engine cools down the coolant, it will be drawn from the reserve/overflow tank into the radiator to replace any removed air.

Scheme 22

1. DO NOT remove radiator cap first. With engine cold, raise vehicle on a hoist and locate radiator draincock. NOTE: Radiator draincock is located on the right/lower side of radiator facing to rear of vehicle.
2. Attach one end of a hose to the draincock. Put the other end into a clean container. Open draincock and drain coolant from radiator. This will empty the coolant reserve/overflow tank. The coolant does not have to be removed from the tank unless the system is being refilled with a fresh mixture. When tank is empty, remove radiator cap and continue draining cooling system.

Scheme 23

Evacuating or purging air from the cooling system involves the use of a pressurized air operated vacuum generator. The vacuum created allows for a quick and complete coolant refilling while removing any airlocks present in the system components.

Note. To avoid damage to the cooling system, ensure that no component would be susceptible to damage when a vacuum is drawn on the system.

Note. The service area where this procedure is performed should have a minimum shop air requirement of 80 PSI (5.5 bar) and should be equipped with an air dryer system.

Note. For best results, the radiator should be empty. The vehicle's heater control should be set to the heat position (ignition may need to be turned to the on position but do not start the motor).

Scheme 24

Scheme 25

Scheme 26

Scheme 27

1. Refer to the Chrysler Pentastar Service Equipment (Chrysler PSE) Coolant Refiller #85-15-0650 or equivalent tool's operating manual for specific assembly steps.
2. Choose an appropriate adapter cone that will fit the vehicle's radiator filler neck or reservoir tank.
3. Attach the adapter cone (2) to the vacuum gauge (1).
4. Make sure the vacuum generator/venturi ball valve (3) is closed and attach an airline hose (2) (minimum shop air requirement of 80 PSI/5.5 bar) to the vacuum generator/venturi (1).
5. Position the adaptor cone/vacuum gauge assembly into the radiator filler neck or reservoir tank. Ensure that the adapter cone is sealed properly.
6. Connect the vacuum generator/venturi (2) to the positioned adaptor cone/vacuum gauge assembly (1).
7. Open the vacuum generator/venturi ball valve. NOTE: Do not bump or move the assembly as it may result in loss of vacuum. Some radiator overflow hoses may need to be clamped off to obtain vacuum.
8. Let the system run until the vacuum gauge shows a good vacuum through the cooling system. Refer to the tool's operating manual for appropriate pressure readings. NOTE: If a strong vacuum is being created in the system, it is normal to see the radiator hoses to collapse.
9. Close the vacuum generator/venturi ball valve.
10. Disconnect the vacuum generator/venturi and airline from the adaptor cone/vacuum gauge assembly.
11. Wait approximately 20 seconds, if the pressure readings do not move, the system has no leaks. If the pressure readings move, a leak could be present in the system and the cooling system should be checked for leaks and the procedure should be repeated.
12. Place the tool's suction hose into the coolant's container. NOTE: Ensure there is a sufficient amount of coolant, mixed to the required strength/protection level available for use. For best results and to assist the refilling procedure, place the coolant container at the same height as the radiator filler neck. Always draw more coolant than required. If the coolant level is too low, it will pull air into the cooling system which could result in airlocks in the system.
13. Connect the tool's suction hose (1) to the adaptor cone/vacuum gauge assembly (2).
14. Open the suction hose's ball valve to begin refilling the cooling system.
15. When the vacuum gauge reads zero, the system is filled. NOTE: On some remote pressurized tanks, it is recommended to stop filling when the proper level is reached.
16. Close the suction hose's ball valve and remove the suction hose from the adaptor cone/vacuum gauge assembly.
17. Remove the adaptor cone/vacuum gauge assembly from the radiator filler neck or reservoir tank.
18. With heater control unit in the HEAT position, operate engine with container cap in place.
19. After engine has reached normal operating temperature, shut engine off and allow it to cool. When engine is cooling down, coolant will be drawn into the radiator from the pressure container.
20. Add coolant to the recovery bottle/container as necessary. Only add coolant to the container when the engine is cold. Coolant level in a warm engine will be higher due to thermal expansion. Add necessary coolant to raise container level to the COLD MINIMUM mark after each cool down period.
21. Once the appropriate coolant level is achieved, attach the radiator cap or reservoir tank cap.

ADDING COOLANT

The use of aluminum cylinder blocks, cylinder heads and water pumps requires special corrosion protection. Only Mopar® Antifreeze/Coolant, 5 Year/100, 000 Mile Formula (glycol base coolant with corrosion inhibitors called HOAT, for Hybrid Organic Additive Technology) is recommended. This coolant offers the best engine cooling without corrosion when mixed with 50% distilled water to obtain to obtain a freeze point of -37°C (-35°F). If it loses color or becomes contaminated, drain, flush, and replace with fresh properly mixed coolant solution.

CHEMICAL CLEANING

If visual inspection indicates the formation of sludge or scaly deposits, use a radiator cleaner (Mopar Radiator Kleen or equivalent) before flushing. This will soften scale and other deposits and aid the flushing operation.

3.6L ELECTRONIC POWER STEERING

1. Check condition of all pulleys. CAUTION: When installing the serpentine accessory drive belt, the belt MUST be routed correctly. If not, the engine may overheat due to the water pump rotating in the wrong direction.
2. Install new belt (3). Route the belt around all pulleys except the idler pulley (2). Rotate the tensioner arm (7) until it contacts its stop position. Route the belt (3) around the idler (2) and slowly let the tensioner (7) rotate into the belt. Make sure the belt (3) is seated onto all pulleys.
3. With the drive belt installed, inspect the belt wear indicator. The gap between the tang and the housing stop (measurement A) must not exceed 24 mm (.94 inches).
4. Install the air cleaner intake system.

5.7L ENGINE

Note. When installing accessory drive belt onto pulleys, make sure that belt is properly routed and all V-grooves make proper contact with pulleys.

1. Position the drive belt (2) over all pulleys except for the water pump pulley (7).
2. Rotate tensioner (8) clockwise and slip the belt (2) over the water pump pulley (7).
3. Gently release tensioner (8).
4. Install the air intake tube between intake manifold and air filter assembly.

Scheme 28

1. Remove accessory drive belt. Refer to «TENSIONER, BELT, REMOVAL»(ref-465940-S07481246852012042300000) .
2. Remove bolt (2) and idler pulley (1).

5.7L IDLER BRACKET

Note. The idler bracket takes the place of the power steering pump on the vehicles that use electronic power steering.

Scheme 29

1. Remove the accessory drive belt. Refer to «BELT, SERPENTINE, REMOVAL»(ref-465940-S20367993122012042300000) .
2. Remove the idler pulley (4) from the idler bracket (2).
3. Remove the three mounting bolts (3) that hold the idler bracket (2) to the block.

3.6L

1. Remove main drive belt (4). Refer to «BELT, SERPENTINE, REMOVAL»(ref-465940-S20367993122012042300000) .
2. Remove the mounting bolt holding the idler pulley (1).

5.7/6.4L

1. Position idler pulley (1).
2. Tighten bolt (2) to 29 N.m (21 ft. lbs.).
3. Install accessory drive belt. Refer to «BELT, SERPENTINE, INSTALLATION»(ref-465940-S28892887022012042300000) .

1. Position the idler bracket to the engine block. Install the three mounting bolts (3). Tighten bolts to 29 N.m (21 ft. lbs.).
2. Install the idler pulley (4). Tighten bolt (5) to 29 N.m (21 ft. lbs.).
3. Install the accessory drive belt. Refer to «BELT, SERPENTINE, INSTALLATION»(ref-465940-S28892887022012042300000) .

Scheme 30

1. Install bolt for idler pulley (4).
2. Install main drive belt. Refer to «BELT, SERPENTINE, INSTALLATION»(ref-465940-S28892887022012042300000) .

1. Disconnect the negative battery cable.
2. Remove the air intake system. Refer to «BODY, AIR CLEANER, REMOVAL»(ref-465933-S00984640022012042300000) or «BODY, AIR CLEANER, REMOVAL, 5.7L»(ref-465934-S30952154692012042300000) .
3. Remove main drive belt. Refer to «BELT, SERPENTINE, REMOVAL»(ref-465940-S20367993122012042300000) .
4. Remove tensioner assembly from engine front cover.

Scheme 31

1. Disconnect the negative battery cable.
2. Remove the air intake system. Refer to «BODY, AIR CLEANER, REMOVAL»(ref-465933-S00984640022012042300000) or «BODY, AIR CLEANER, REMOVAL, 5.7L»(ref-465934-S30952154692012042300000) .
3. Remove accessory drive belt Refer to «BELT, SERPENTINE, REMOVAL»(ref-465940-S20367993122012042300000) .
4. Remove bolt (3) and tensioner assembly.

1. An indexing slot is located on back of tensioner. Align this slot to the head of the bolt on the front cover. Install the mounting bolt. Tighten bolt to 41 N.m (30 ft. lbs.).
2. Install main drive belt. Refer to «BELT, SERPENTINE, INSTALLATION»(ref-465940-S28892887022012042300000) .
3. Check belt indexing marks.
4. Install the air intake system. Refer to «BODY, AIR CLEANER, INSTALLATION»(ref-465933-S30773472812012042300000) or «BODY, AIR CLEANER, INSTALLATION, 5.7L»(ref-465934-S26716388022012042300000) .
5. Connect the negative battery.

5.7L

1. Align locator tang on tensioner with slot in front cover.
2. Install tensioner and mounting bolt (3) to front cover. Tighten bolt to 41 N.m (30 ft. lbs.).
3. Install accessory drive belt. Refer to «BELT, SERPENTINE, INSTALLATION»(ref-465940-S28892887022012042300000) .
4. Install the air intake system. Refer to «BODY, AIR CLEANER, INSTALLATION»(ref-465933-S30773472812012042300000) or «BODY, AIR CLEANER, INSTALLATION, 5.7L»(ref-465934-S26716388022012042300000) .
5. Connect the negative battery.

Scheme 32

1. Remove the overflow tube (3) to the recovery bottle (1).
2. Remove the mounting bolts (4) to the recovery bottle.
3. Remove the recovery bottle (1).
4. Remove any excessive coolant into a clean container.

3.6L/5.7L

1. Position recovery bottle (1) into vehicle.
2. Install mounting nuts (4). Tighten to 10 N.m (89 in. lbs.).
3. Install the overflow tube (3) to the radiator neck (2).

Scheme 33

All radiators are equipped with a pressure cap. This cap releases pressure at some point within a range of 110 - 138 kPa (16 - 20 psi). The pressure relief point (in pounds) is engraved on top of the cap

The cooling system will operate at pressures slightly above atmospheric pressure. This results in a higher coolant boiling point allowing increased radiator cooling capacity. The cap contains a spring-loaded pressure relief valve. This valve opens when system pressure reaches the release range of 110 - 138 kPa (16 - 20 psi).

A rubber gasket seals the radiator filler neck. This is done to maintain vacuum during coolant cool-down and to prevent leakage when system is under pressure.

Scheme 34

Remove cap from radiator. Be sure that sealing surfaces are clean. Moisten rubber gasket with water and install the cap on pressure tester (tool (special tool #7700, Tester, Cooling System) or an equivalent).

Operate the tester pump and observe the gauge pointer at its highest point. The cap release pressure should be 110 to 138 kPa (16 - 20 psi). The cap is satisfactory when the pressure holds steady. It is also good if it holds pressure within the 110 - 138 kPa (16 - 20 psi) range for 30 seconds or more. If the pointer drops quickly, replace the cap.

ENGINE COOLANT

ETHYLENE-GLYCOL MIXTURES

The use of aluminum cylinder blocks, cylinder heads and water pumps requires special corrosion protection. Only Mopar® Antifreeze/Coolant, 5 year/100, 000 Mile Formula (ethylene-glycol base coolant with corrosion inhibitors called HOAT, for Hybrid Additive Technology) is recommended. This coolant offers the best engine cooling without corrosion when mixed with 50% distilled water to obtain a freeze point of -37°C (-35°F).

The required ethylene-glycol (antifreeze) and water mixture depends upon the climate and vehicle operating conditions. The antifreeze concentration must always be a minimum of 44 percent, year-round in all climates. If percentage is lower than 44 percent, engine parts may be eroded by cavitation, and cooling system components may be severely damaged by corrosion. Maximum protection against freezing is provided with a 68% antifreeze concentration, which prevents freezing down to -67.7° C (-90° F). A higher percentage will freeze at a warmer temperature. Also, a higher percentage of antifreeze can cause the engine to overheat because the specific heat of antifreeze is lower than that of water.

Use of 100 percent ethylene-glycol will cause formation of additive deposits in the system, as the corrosion inhibitive additives in ethylene-glycol require the presence of water to dissolve. The deposits act as insulation, causing temperatures to rise to as high as 149°C (300°F). This temperature is hot enough to melt plastic and soften solder. The increased temperature can result in engine detonation. In addition, 100 percent ethylene-glycol freezes at 22°C (-8°F).

PROPYLENE-GLYCOL MIXTURES

It's overall effective temperature range is smaller than that of ethylene-glycol. The freeze point of 50/50 propylene-glycol and water is -32°C (-26°F). 5°C higher than ethylene-glycol's freeze point. The boiling point (protection against summer boil-over) of propylene-glycol is 125°C (257°F) at 96.5 kPa (14 psi), compared to 128°C (263°F) for ethylene-glycol. Use of propylene-glycol can result in boil-over or freeze-up on a cooling system designed for ethylene-glycol. Propylene glycol also has poorer heat transfer characteristics than ethylene glycol. This can increase cylinder head temperatures under certain conditions.

Propylene-glycol/ethylene-glycol Mixtures can cause the destabilization of various corrosion inhibitors, causing damage to the various cooling system components. Also, once ethylene-glycol and propylene-glycol based coolants are mixed in the vehicle, conventional methods of determining freeze point will not be accurate. Both the refractive index and specific gravity differ between ethylene glycol and propylene glycol.

HOAT COOLANT

The cooling system is designed around the coolant. The coolant must accept heat from engine metal, in the cylinder head area near the exhaust valves and engine block. Then coolant carries the heat to the radiator where the tube/fin radiator can transfer the heat to the air.

The use of aluminum cylinder blocks, cylinder heads, and water pumps requires special corrosion protection. Mopar® Antifreeze/Coolant, 5 Year/100, 000 Mile Formula (MS-9769), or the equivalent ethylene-glycol base coolant with organic corrosion inhibitors (called HOAT, for Hybrid Organic Additive Technology) is recommended. This coolant offers the best engine cooling without corrosion when mixed with 50% ethylene-glycol and 50% distilled water to obtain a freeze point of -37°C (-35°F). If it loses color or becomes contaminated, drain, flush, and replace with fresh properly mixed coolant solution.

COOLANT PERFORMANCE

The required ethylene-glycol (antifreeze) and water mixture depends upon climate and vehicle operating conditions. The coolant performance of various mixtures follows

Pure Water- Water can absorb more heat than a mixture of water and ethylene-glycol, but this is not suitable for use in a cooling system. Water also freezes at a higher temperature, boils at a lower temperature and allows corrosion.

100 percent Ethylene-Glycol - The corrosion inhibiting additives in ethylene-glycol need the presence of water to dissolve. Without water, additives form deposits in system. These act as insulation causing temperature to rise to as high as 149°C (300°F). This temperature is hot enough to melt plastic and soften solder. The increased temperature can result in engine detonation. In addition, 100 percent ethylene-glycol freezes at -22°C (-8°F).

50/50 Ethylene-Glycol and Water - Is the recommended mixture, it provides protection against freezing to -37°C (-34°F). The antifreeze concentration must always be a minimum of 44 percent, year-round in all climates. If percentage is lower, engine parts may be eroded by cavitation. Maximum protection against freezing is provided with a 68 percent antifreeze concentration, which prevents freezing down to -67.7°C (-90°F). A higher percentage will freeze at a warmer temperature. Also, a higher percentage of antifreeze can cause the engine to overheat because specific heat of antifreeze is lower than that of water.

COOLANT SELECTION AND ADDITIVES

The use of aluminum cylinder blocks, cylinder heads and water pumps requires special corrosion protection. Only Mopar® Antifreeze/Coolant, 5 Year/100, 000 Mile Formula (glycol base coolant with corrosion inhibitors called HOAT, for Hybrid Organic Additive Technology) is recommended. This coolant offers the best engine cooling without corrosion when mixed with 50% distilled water to obtain to obtain a freeze point of -37°C (-35°F). If it loses color or becomes contaminated, drain, flush, and replace with fresh properly mixed coolant solution.

STANDARD COOLING FAN STRATEGY

The radiator cooling fan used on the engines replaces the engine driven mechanical fan and the hydraulically controlled fan. This provides cooling at 350 watts to the light duty cooling systems on the vehicles. Helps in reducing unnecessary power drain on both the engine and the vehicles electrical system while keeping the NVH of the fan low.

The cooling fan is controlled by the PCM. A ground signal from the PCM is provide for the LOW fan relay. If the conditions are required for additional cooling. The PCM provides a ground to the HIGH relay.

There are three inputs to the PCM that determine what speed percentage of fan is required by the vehicle. These inputs are

1. Engine Coolant Temperature
2. Transmission Oil Temperature
3. A/C System Pressure

By monitoring these three parameters, the PCM can determine if cooling airflow is required. If airflow is required, the PCM will ground the required fan relay until the parameter(s) are under control. Once the temperature is reduced to within operating parameters the fan will ramp up or ramp down to maintain the temperature requirements.

MAX COOLING FAN STRATEGY

The radiator cooling fan used on the engines replaces the engine driven mechanical fan and the hydraulically controlled fan. This provides max cooling at 850 watts to the vehicles that require the additional cooling.

The radiator cooling fan is controlled by the PCM. A PWM (Pulse With Modulated) signal from the PCM controls the fan speed.

There are three inputs to the PCM that determine what speed percentage of fan is required by the vehicle. These inputs are

1. Engine Coolant Temperature
2. Transmission Oil Temperature
3. A/C System Pressure

By monitoring these three parameters, the PCM can determine if cooling airflow is required. If airflow is required, the PCM will send a signal to the fan module to slowly ramp up (speed up) the fan speed until the parameter(s) are under control. Once the temperature is reduced to within operating parameters the fan will ramp up, ramp down, or hold its speed to maintain the temperature requirements, while reducing unnecessary power drain on both the engine and the vehicles electrical system and keeping the NVH of the fan low.

ELECTRIC RADIATOR FAN

The powertrain control module (PCM) will enter a diagnostic trouble code (DTC) in memory if it detects a problem in the auxiliary cooling fan relay or circuit. Refer to DESCRIPTION .

If the electric cooling fan is inoperative, check the 15A fuse in the junction block and the 40A fuse in the Power Distribution Center (PDC) with a 12 volt test lamp or DVOM. Refer to the inside of the power distribution center cover for the exact location of the fuse. If fuses are okay, refer to appropriate information for the cooling fan and relay circuit schematic.

Scheme 35

Scheme 36

Scheme 37

1. Disconnect negative battery cable. Refer to «CABLES, BATTERY, REMOVAL»(ref-465932-S24943704712012042300000) .
2. Remove the air intake assembly.
3. Raise vehicle. NOTE: The lower shroud cover needs to be removed in order to remove the cooling fan assembly from the mounting tabs.
4. If equipped, remove the lower engine shield.
5. Remove the lower shroud cover (4) by using a pick (2) to pull the cover retaining hole away from the clip (3) along the bottom of the cooling fan assembly (1).
6. Lower vehicle.
7. Disconnect electric fan connector (1). NOTE: The cooling fan assembly is held in place by clips that are part of the radiator. So care must be used so the clips are not damaged during fan removal.
8. Remove shroud (3) assembly from vehicle by pressing the locking clips (2) inwards with a flat blade screwdriver.
9. Pull the fan/shroud assembly upwards and away from the radiator with the upper cooling fan assembly shroud cover in place.
10. Remove the cooling fan assembly from vehicle.
11. Remove the upper fan shroud cover (1) by using a pick (3) to pull the cover retaining hole away from the clip (2).

CLEANING

Clean the fan blades using a mild soap and water. Do not use an abrasive to clean the blades.

Scheme 38

1. Install the upper shroud cover (1). Apply pressure downwards until the cover snaps into place past clips (2).
2. Install cooling fan assembly into vehicle.
3. Guide the fan/shroud cover assembly into position between the radiator and upper core support.
4. Position cooling fan assembly onto the mounts (3) located on the radiator.
5. Lock in the fan (1) assembly into place by pressing down firmly on the shroud till the locks (3) engage.
6. Connect electric fan electrical connector (2).
7. Raise the vehicle.
8. Install the lower cooling shroud cover by applying upwards pressure till the cover snaps into place onto the cooling fan shroud.
9. If equipped, install the lower engine cover.
10. Lower vehicle.
11. Connect negative battery cable.
12. Install the air intake assembly.
13. Start engine and check fan operation.

Scheme 39

An optional engine block heater (2) is available with all models. The heater is equipped with a power cord. The cord is attached to an engine compartment component with tie-straps. The heater warms the engine providing easier engine starting and faster warm-up in low temperatures. The heater is mounted in a core hole of the engine cylinder block in place of a freeze plug with the heating element immersed in engine coolant.

Scheme 40

The 5.7L engine has the block heater (1) located on the left side of the engine below the exhaust manifold in the rear of the engine and is not immersed in engine coolant but makes direct contact with the block. (Scheme 38)

Scheme 41

If the unit does not operate, possible causes can be either the power cord or the heater element. Test the power cord for continuity with a 110-volt voltmeter or 110-volt test light. Test heater element continuity with an ohmmeter or a 12-volt test light.

Scheme 42

Scheme 43

1. Remove the A/C compressor (1) and position aside. Refer to «COMPRESSOR, A/C, REMOVAL»(ref-465931-S23974274942012042300000) . The heater block is located on the driver side towards the front of the engine.
2. Partially drain coolant from radiator and cylinder block. Refer to «STANDARD PROCEDURE»(ref-465940-S34230748332012042300000) .
3. Disconnect the power cord plug from block heater.
4. Loosen screw (2) from the heater. Remove block heater assembly (1).

1. Raise vehicle.
2. Remove power cord from block heater (2).
3. Remove bolt (3) on block heater (2). Remove heater assembly (2).

3.6L ENGINE

1. Clean block core hole and heater seat.
2. Insert heater block (1) assembly.
3. With block heater seated, tighten screw (2) to 12N.M (106 in.lbs.) to assure a positive seal.
4. Install power cord plug to block heater (1).
5. Fill cooling system with coolant to the proper level. Refer to «STANDARD PROCEDURE»(ref-465940-S34230748332012042300000) .
6. Install the A/C compressor. Refer to «COMPRESSOR, A/C, INSTALLATION»(ref-465931-S33917266512012042300000) .

1. Thoroughly clean cylinder block core hole and block heater seat.
2. Insert block heater assembly (2) into the block.
3. With block heater fully seated, tighten bolt (3) to 12 N.m (106 in. lbs.) torque.
4. Connect power cord to block heater (2).

Scheme 44

A centrifugal water pump (2) circulates coolant through the water jackets, passages, intake manifold, radiator core, cooling system hoses and heater core. The pump is driven from the engine crankshaft by a single serpentine main drive belt.

The water pump impeller is pressed onto the rear of a shaft that rotates in bearings pressed into the housing. The housing has two small holes to allow seepage to escape. The water pump seals are lubricated by the antifreeze in the coolant mixture. No additional lubrication is necessary.

The water pump (1) is mounted directly to the timing chain cover and is equipped with a non serviceable integral pulley.

WATER PUMP

A centrifugal water pump circulates coolant through the water jackets, passages, intake manifold, radiator core, cooling system hoses and heater core, this coolant absorbs the heat generated when the engine is running. The pump is driven by the engine crankshaft via a drive belt.

LOOSE IMPELLER - 3.6/5.7L ENGINES

Note. Due to the design of the 3.6/5.7L engine water pumps, testing the pump for a loose impeller must be done by verifying coolant flow in the radiator. To accomplish this refer to the following procedure.

DO NOT WASTE reusable coolant. If solution is clean, drain coolant into a clean container for reuse.

1. Drain coolant until the first row of cores is visible in the radiator. Refer to «STANDARD PROCEDURE»(ref-465940-S34230748332012042300000) .
2. Leaving the radiator cap off, start the engine. Run engine until thermostat opens.
3. While looking into the radiator through the radiator fill neck, raise engine RPM to 2000 RPM. Observe the flow of coolant from the first row of cores.
4. If there is no flow or very little flow visible, replace the water pump.

Clean the gasket mating surface. Use caution not to damage the gasket sealing surface.

1. Clean mating surfaces and install water pump (3). Tighten mounting bolts to 24 N.m (18 ft. lbs.).
2. Install upper metal heater tube.
3. Install belt tensioner assembly (4). Refer to «TENSIONER, BELT, INSTALLATION»(ref-465940-S29219199702012042300000) .
4. Install idler pulley (5).
5. Install the lower radiator hose.
6. Install serpentine belt. Refer to «BELT, SERPENTINE, INSTALLATION»(ref-465940-S28892887022012042300000) .
7. Install the resonator mounting bracket.
8. Install cooling fan assembly. Refer to «FAN, COOLING, INSTALLATION»(ref-465940-S22919138712012042300000) .
9. Install the upper radiator hose to the thermostat housing (1).
10. Install the air intake assembly. Refer to «BODY, AIR CLEANER, INSTALLATION»(ref-465933-S30773472812012042300000) or «BODY, AIR CLEANER, INSTALLATION, 5.7L»(ref-465934-S26716388022012042300000) .
11. Connect negative battery cable.
12. Evacuate air and refill cooling system. Refer to «STANDARD PROCEDURE»(ref-465940-S34230748332012042300000) .
13. Check cooling system for leaks. Refer to «DIAGNOSIS AND TESTING»(ref-465940-S27246341182012042300000) .

Scheme 45

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 46

Do not waste reusable coolant. If the solution is clean, drain the coolant into a clean container for reuse.

Scheme 47

1. Disconnect the negative battery cable at battery.
2. Drain coolant from radiator. Refer to «STANDARD PROCEDURE»(ref-465940-S34230748332012042300000) .
3. Remove the A/C condenser (4). Refer to «CONDENSER, A/C, REMOVAL»(ref-465931-S20788130062012042300000) .
4. Remove the upper radiator crossmember.
5. Disconnect the upper radiator hose.
6. Disconnect the overflow hose from radiator.
7. Remove the cooling fan assembly. Refer to «FAN, COOLING, REMOVAL»(ref-465940-S32398312912012042300000) .
8. Remove the lower radiator hose from the water pump.
9. The lower part of the radiator is equipped with two alignment dowel pins and fit into rubber grommets. These rubber grommets are pressed onto the radiator.
10. Gently lift up and remove radiator from vehicle. Be careful not to scrape the radiator fins against any other component.
11. Remove the lower radiator hose from the radiator.

GAS ENGINES

Scheme 48

1. Gently lower the radiator (1) into the vehicle. Guide the two radiator rubber air seals into the lower radiator support. CAUTION: The tangs on the hose clamps must be positioned straight down.
2. Install the lower radiator hose to the lower radiator outlet.
3. Install the cooling fan assembly. Refer to «FAN, COOLING, INSTALLATION»(ref-465940-S22919138712012042300000) .
4. Install coolant reserve/overflow tank hose at radiator.
5. Install the upper radiator hose.
6. Install the upper radiator crossmember. Align the upper radiator alignment dowel into the upper isolators.
7. Install the A/C condenser. Refer to «CONDENSER, A/C, INSTALLATION»(ref-465931-S35091896602012042300000) .
8. Refill cooling system. Refer to «STANDARD PROCEDURE»(ref-465940-S34230748332012042300000) .
9. Refill the power steering reservoir and bleed air from system. Refer to «STANDARD PROCEDURE»(ref-465942-S26922506192012042300000) .
10. Connect battery cable at battery.
11. Start and warm engine. Check for leaks.

5.7L/6.4L

The Engine Coolant Temperature (ECT) sensor is located on the upper portion of the water pump housing. It is installed into a water jacket inline with the thermostat.

Scheme 49

1. Remove the air intake system. Refer to «BODY, AIR CLEANER, REMOVAL»(ref-465933-S00984640022012042300000) or «BODY, AIR CLEANER, REMOVAL, 5.7L»(ref-465934-S30952154692012042300000) . NOTE: Do not waste reusable coolant. If solution is clean, drain coolant into a clean container for reuse.
2. Partially drain the cooling system. Refer to «STANDARD PROCEDURE»(ref-465940-S34230748332012042300000) .
3. Disconnect electrical connector (3) from sensor (2).
4. Remove sensor from the water pump housing.

1. Apply MOPAR™ thread sealant with PFTE part number 04318034 to sensor threads.
2. Install sensor (1) to cylinder head.
3. Tighten sensor to 11 N.m (8 ft. lbs.) torque.
4. Connect electrical connector to sensor.
5. Replace any lost engine coolant. Refer to «STANDARD PROCEDURE»(ref-465940-S34230748332012042300000) .

5.7L / 6.4L

1. Apply MOPAR® thread sealant with PFTE to the sensor threads.
2. Install the coolant temperature sensor (2) into water pump housing.
3. Tighten the coolant temperature sensor to 11 N.m (8 ft. lbs.).
4. Connect the coolant temperature sensor electrical connector (3).
5. Install air intake system. Refer to «BODY, AIR CLEANER, INSTALLATION»(ref-465933-S30773472812012042300000) or «BODY, AIR CLEANER, INSTALLATION, 5.7L»(ref-465934-S26716388022012042300000) .
6. Replace any lost engine coolant. Refer to «STANDARD PROCEDURE»(ref-465940-S34230748332012042300000) .

Scheme 50

A pellet-type thermostat controls the operating temperature of the engine by controlling the amount of coolant flow to the radiator. On all engines the thermostat is closed below 195°F (90°C). Above this temperature, coolant is allowed to flow to the radiator. This provides quick engine warm up and overall temperature control.

The same thermostat is used for winter and summer seasons. An engine should not be operated without a thermostat, except for servicing or testing. Operating without a thermostat causes other problems. These are: longer engine warm-up time, unreliable warm-up performance, increased exhaust emissions and crankcase condensation. This condensation can result in sludge formation.

The thermostat is part of the housing.

Do not waste reusable coolant. If solution is clean, drain coolant into a clean container for reuse.

If thermostat is being replaced, be sure that replacement is specified thermostat for vehicle model and engine type.

1. Disconnect negative battery cable at battery.
2. Remove the air intake assembly. Refer to «BODY, AIR CLEANER, REMOVAL»(ref-465933-S00984640022012042300000) or «BODY, AIR CLEANER, REMOVAL, 5.7L»(ref-465934-S30952154692012042300000) .
3. Drain cooling system. Refer to «STANDARD PROCEDURE»(ref-465940-S34230748332012042300000) .
4. Remove upper radiator hose clamp and upper radiator hose at thermostat housing (1).
5. Remove thermostat housing mounting bolts, thermostat housing (1) and thermostat (3).

Scheme 51

1. Remove the thermostat housing assembly. Refer to «THERMOSTAT, REMOVAL»(ref-465940-S21622086222012042300000) .
2. Remove the Heater supply hose from the coolant crossover (1).
3. Remove the coolant crossover mounting bolts. Take notice to the four bolts (2) that bolt directly to the timing cover.
4. Remove the coolant crossover and discard Gaskets.

Scheme 52

Do not waste reusable coolant. If the solution is clean, drain the coolant into a clean container for reuse.

If the thermostat is being replaced, be sure that the replacement is the specified thermostat for the vehicle model and engine type.

1. Disconnect the negative battery cable.
2. Remove the air intake system. Refer to «BODY, AIR CLEANER, REMOVAL»(ref-465933-S00984640022012042300000) or «BODY, AIR CLEANER, REMOVAL, 5.7L»(ref-465934-S30952154692012042300000) .
3. Partially drain the cooling system. Refer to «STANDARD PROCEDURE»(ref-465940-S34230748332012042300000) .
4. Remove the upper radiator hose at the thermostat housing (2) and position aside.
5. Remove the thermostat housing mounting bolts (1), thermostat housing (2) and thermostat.

1. Clean mating areas of timing chain cover and thermostat housing (1).
2. Install a new gasket on to the thermostat housing.
3. Position thermostat housing (1) on the water crossover.
4. Install two thermostat housing bolts. Tighten bolts to 12 N.m (106 in. lbs.).
5. Install upper radiator hose on thermostat housing (1).
6. Fill cooling system. Refer to «STANDARD PROCEDURE»(ref-465940-S34230748332012042300000) .
7. Install the air intake system. Refer to «BODY, AIR CLEANER, INSTALLATION»(ref-465933-S30773472812012042300000) or «BODY, AIR CLEANER, INSTALLATION, 5.7L»(ref-465934-S26716388022012042300000) .
8. Connect negative battery cable to battery.
9. Start and warm the engine. Check for leaks.

3.6L COOLANT CROSSOVER

1. Clean gasket sealing surfaces.
2. Install new gasket onto the coolant crossover. NOTE: The shorter M6 mounting bolts (2), bolt directly to the engine timing cover.
3. Hand tighten the M6 mounting bolts. Tighten the bolts in a criss cross pattern to 12 N.m (106 in. lbs.).
4. Install the heater supply hose to the coolant crossover (1).
5. Install the thermostat housing. Refer to «THERMOSTAT, INSTALLATION»(ref-465940-S10648687442012042300000) .

1. Position the thermostat and housing (2) on the front cover.
2. Install thermostat housing bolts (1). Tighten the bolts (1) to 13 N.m (115 in. lbs.).
3. Install the radiator hose onto the thermostat housing (2).
4. Fill the cooling system. Refer to «STANDARD PROCEDURE»(ref-465940-S34230748332012042300000) .
5. Connect negative battery cable.
6. Install the air intake system. Refer to «BODY, AIR CLEANER, INSTALLATION»(ref-465933-S30773472812012042300000) or «BODY, AIR CLEANER, INSTALLATION, 5.7L»(ref-465934-S26716388022012042300000) .
7. Start and warm the engine. Check for leaks. Refer to «DIAGNOSIS AND TESTING»(ref-465940-S27246341182012042300000) .