Overview
Description
The cooling system regulates engine operating temperature. It allows the engine to reach normal operating temperature as quickly as possible, maintains normal operating temperature and prevents overheating.
The cooling system also provides a means of heating the passenger compartment. The cooling system is pressurized and uses a centrifugal water pump to circulate coolant throughout the system. A separate and remotely mounted, pressurized coolant tank using a pressure/vent cap is used.
COOLING SYSTEM COMPONENTS
The cooling system consists of:
Charge Air Cooler (Turbocharged vehicles only) 2 Speed Electric Cooling Fan Engine driven fan with viscous clutch (Diesel Engine) A aluminum-core radiator with plastic side tanks Combined Coolant Recover Container/Washer Reservoir (Gas Engine) Combined coolant pressure bottle/overflow system with pressure cap Radiator Water pump Combination A/C condenser/transmission oil cooler (automatic transmission) Thermostat Coolant Water pump Hoses and hose clamps
Operation
1 - LH CYL. HEAD 2 - AIR BLEED 3 - THERMOSTAT LOCATION 4 - RH CYL. HEAD 5 - RH BANK CYL. BLOCK 6 - LH BANK CYL. BLOCK 7 - COOLANT TEMP. SENSOR
The cooling system regulates engine operating temperature. It allows the engine to reach normal operating temperature as quickly as possible. It also maintains normal operating temperature and prevents overheating.
The cooling system also provides a means of heating the passenger compartment. The cooling system is pressurized and uses a centrifugal water pump to circulate coolant throughout the system.
AERATION
Low coolant level in a cross flow radiator will equalize in both tanks with engine off. With engine running and at operating temperature, the high pressure inlet tank runs full and the low pressure outlet tank drops, resulting in cooling system aeration. Aeration will draw air into the water pump resulting in the following:
High reading shown on the temperature gauge. Loss of coolant flow through the heater core. Corrosion in the cooling system. Water pump seal may run dry, increasing the risk of premature seal failure. Combustion gas leaks into the coolant can also cause aeration.
DEAERATION
Air can only be removed from the system by gathering under the pressure cap. On the next heat up it will be pushed past the pressure cap into the coolant recovery bottle by thermal expansion of the coolant. It then escapes to the atmosphere in the coolant recovery bottle and is replaced with coolant on cool down.
To effectively deaerate the system, multiple thermal cycles of the system may be required.
NOTE: Deaeration does not occur at engine idle, higher engine speeds are required. Normal driving will deaerate cooling system.
FLOW CHECK-DIESEL
To determine whether coolant is flowing through the cooling system, use the following procedures:
1. If engine is cold, idle engine until normal operating temperature is reached. Then feel the upper radiator hose. If it is hot, coolant is circulating.
WARNING: Do not remove the cooling system pressure cap with the system hot and under pressure because serious burns from coolant can occur.
2. Remove pressure/vent cap when engine is cold, idle engine until thermostat opens, you should observe coolant flow while looking down in the coolant recovery pressure container. Once flow is detected install the pressure/vent cap.
ULTRAVIOLET LIGHT METHOD
1 - TYPICAL BLACK LIGHT TOOL
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 (1) can be used in conjunction with a pressure tester to determine if any external leaks exist.
PRESSURE TESTER METHOD
1 - TYPICAL COOLING SYSTEM PRESSURE TESTER
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.
WARNING: Hot, pressurized coolant can cause injury by scalding.
Carefully remove radiator pressure cap from pressure bottle 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, and dirt. 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 (7700 or an equivalent) to radiator filler neck.
Operate tester pump (1) to apply 110 kPa (16 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 INSPECTION.
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.
INTERNAL LEAKAGE INSPECTION
Remove engine oil pan drain plug and drain a small amount of engine oil. If coolant is present in the pan, it will drain first because it is heavier than oil. An alternative method is to operate engine for a short period to churn the oil. After this is done, remove engine dipstick and inspect for water globules. Also inspect transmission dipstick for water globules and transmission fluid cooler for leakage.
WARNING: With radiator pressure tester tool installed on radiator, do not allow pressure to exceed 124 kpa (18 psi). Pressure will build up quickly if a combustion leak is present. To release pressure, rock tester from side to side. When removing tester, do not turn tester more than 1/2 turn if system is under pressure.
Operate engine without pressure cap on radiator until thermostat opens. Attach a Pressure Tester to filler neck. If pressure builds up quickly it indicates a combustion leak exists. This is usually the result of a cylinder head gasket leak or crack in engine. Repair as necessary.
If there is not an immediate pressure increase, pump the Pressure Tester. Do this until indicated pressure is within system range of 110 kPa (16 psi). Fluctuation of gauge pointer indicates compression or combustion leakage into cooling system.
Because the vehicle is equipped with a catalytic converter, do not remove spark plug cables or short out cylinders to isolate compression leak.
If the needle on dial of pressure tester does not fluctuate, race engine a few times to check for an abnormal amount of coolant or steam. This would be emitting from exhaust pipe. Coolant or steam from exhaust pipe may indicate a faulty cylinder head gasket, cracked engine cylinder block or cylinder head.
A convenient check for exhaust gas leakage into cooling system is provided by a commercially available Block Leak Check tool. Follow manufacturers instructions when using this product.
COMBUSTION LEAKAGE TEST - WITHOUT PRESSURE TESTER
DO NOT WASTE reusable coolant. If solution is clean, drain coolant into a clean container for reuse.
WARNING: Do not remove cylinder block drain plugs or loosen radiator draincock with system hot and under pressure. Serious burns from coolant can occur.
Drain sufficient coolant to allow thermostat removal. See REMOVAL. Remove accessory drive belt, see
COOLING SYSTEM RELATED DIAGNOSTICS
The Powertrain Control Module (PCM) has been programmed to monitor certain cooling system components:
If the engine has remained cool for too long a period, such as with a stuck open thermostat, a Diagnostic Trouble Code (DTC) can be set. If an open or shorted condition has developed in the relay circuit controlling the electric radiator fan, a Diagnostic Trouble Code (DTC) can be set.
If the problem is sensed in a monitored circuit often enough to indicate an actual problem, a DTC is stored. The DTC will be stored in the PCM memory for eventual display to the service technician. Refer to OPERATION .
ACCESSING DIAGNOSTIC TROUBLE CODES
To read DTC's and to obtain cooling system data. Refer to OPERATION .
ERASING TROUBLE CODES
After the problem has been repaired, use the diagnostic scan tool to erase a DTC. Refer to the appropriate Powertrain Diagnostic Procedures information for operation of the diagnostic scan tool.
ENGINE COOLING SYSTEM OVERHEATING
Establish what driving conditions caused the complaint. Abnormal loads on the cooling system such as the following may be the cause:
Prolonged idle Very high ambient temperature Slight tail wind at idle Slow traffic Traffic jams High speed or steep grades Any accessory that fully or partially blocks grill opening
RECENT SERVICE OR ACCIDENT REPAIR:
Engine adjustments (incorrect timing) Slipping accessory drive belt Brakes (possibly dragging) Changed parts (incorrect water pump) 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.
TRAILER TOWING:
Consult Trailer Towing section of owners manual. Do not exceed limits.
These charts are to be used as a quick-reference only.
CONDITION POSSIBLE CAUSES CORRECTION
TEMPERATURE GAUGE READS 1. Has a Diagnostic Trouble 1. Refer to OPERATION . LOW Code (DTC) been set indicating Replace thermostat if necessary.
a stuck open thermostat?
2. Is the temperature sending 2. Check the temperature sensor
unit connected? connector. SeeDESCRIPTION. Repair connector if necessary.
3. Is the temperature gauge 3. Check gauge operation.
operating OK? Repair as necessary.
4. Coolant level low in cold 4. Check coolant level in the
ambient temperatures coolant pressure bottle and theaccompanied with poor heater radiator. Inspect system for performance. leaks. Repair leaks as necessary.
5. Improper operation of 5. Inspect heater and repair as internal heater doors or heater necessary. Refer to controls. DIAGNOSIS AND TESTING
(ELECTRICAL
DIAGNOSTICS). Refer to
(SERVICE INFORMATION).
6. Electric fan functioning when 6. Inspect electric fan for proper not required. operation. Refer to FAN-
ELECTRICAL
DIAGNOSTICS ). Repair as necessary. 3. Is the temperature warning 3. Check warning lamp illuminating unnecessarily? operation. (Refer to
ELECTRICAL
DIAGNOSTICS ). Repair as necessary.
4. Coolant low in coolant 4. Check for coolant leaks and
pressure bottle and radiator? repair as necessary.
5. Pressure cap not installed 5. Tighten cap.tightly. If cap is loose, boiling point of coolant will be lowered. Also refer to the following Step 6. 6. Poor seals at the radiator cap. 6. (a) Check condition of cap and cap seals. See
TESTING.
(b) Check condition of radiator filler neck. If neck is bent or damaged, replace radiator.
7. Coolant not flowing through 7. (a) Check condition of system. pressure bottle cap and cap seals. See DIAGNOSIS AND
TESTING.
(b) Check condition of the hose from the radiator to the coolant tank. It should fit tight at both ends without any kinks or tears. Replace hose if necessary. (c) Check pressure bottle/overflow tank and tank's hoses for blockage. Repair as necessary.
8. Incorrect coolant 8. Check coolant. See concentration DESCRIPTION for correct
coolant/water mixture ratio. 9. Radiator or A/C condenser 9. Remove insects and debris. fins are dirty or clogged. 10. Radiator core is corroded or 10. Replace radiator. plugged.
11. Fuel or ignition system 11. Refer to FUEL SYSTEM problems. or IGNITION CONTROL -
SERVICE INFORMATION
for diagnosis. 12. Dragging brakes. 12. Check and correct as necessary. Refer to
(BASE - SERVICE
INFORMATION). Refer to
(ABS - ELECTRICAL
DIAGNOSTICS). Refer to
(ABS - SERVICE
INFORMATION). for correct procedures. 13. Bug screen or cardboard is 13. Remove bug screen or being used, reducing airflow. cardboard.
14. Thermostat partially or 14. Check thermostat operation completely shut. and replace as necessary. See
Removal
15
Viscous fan drive not 15. Check fan drive operation
operating properly. and replace as necessary. See
TESTING.
16. Cylinder head gasket 16. Check for cylinder head leaking. gasket leaks. See DIAGNOSIS
AND TESTING. For repair, refer to REMOVAL . 17. Heater core leaking. 17. Check heater core for leaks. Refer to REMOVAL . Repair as necessary. 18. Electric fan not functioning. 18. Inspect electric fan for proper operation. See
TESTING.
TEMPERATURE GAUGE READING 1. During cold weather 1. A normal condition. No IS INCONSISTENT (FLUCTUATES, operation, with the heater correction is necessary. CYCLES OR IS ERRATIC) blower in the high position, the
gauge reading may drop slightly. 2. Temperature gauge or engine 2. Check operation of gauge mounted gauge sensor defective and repair if necessary. Refer to
or shorted. Also, corroded or INSTRUMENT CLUSTER -
loose wiring in this circuit. ELECTRICALDIAGNOSTICS . Refer to
(SERVICE INFORMATION).
3. Gauge reading rises when 3. A normal condition. No vehicle is brought to a stop after correction is necessary. Gauge heavy use (engine still running). should return to normal range after vehicle is driven. 4. Gauge reading high after re- 4. A normal condition. No
starting a warmed up (hot) correction is necessary. The
engine. gauge should return to normalrange after a few minutes of engine operation. 5. Coolant level low in cooling 5. Check and correct coolant
system (air build up in the leaks. See DIAGNOSIS AND
cooling system causing the TESTING.thermostat to open late). 6. Cylinder head gasket leaking 6. (a) Check for cylinder head allowing exhaust gas to enter gasket leaks. Refer to engine
cooling system causing a articles.
thermostat to open late. (b) Check for coolant in theengine oil. Inspect for white steam emitting from the exhaust system. Repair as necessary. 7. Water pump impeller loose 7. Check water pump and on shaft. replace as necessary. 8. Loose accessory drive belt. 8. See DIAGNOSIS AND TESTING. Check and correct as necessary. 9. Air leak on the suction side 9. Locate leak and repair as
of the water pump allows air to necessary. build up in cooling system causing thermostat to open late.
PRESSURE CAP IS BLOWING OFF 1. Pressure relief valve in 1. Check condition of radiator STEAM OR COOLANT TO radiator pressure cap is cap and cap seals. See COOLANT RECOVERY defective. DIAGNOSIS AND CONTAINER. TEMPERATURE TESTING. Replace cap as GAUGE READING MAY BE ABOVE necessary.
HIGH OR HOT
DETONATION OR PRE-IGNITION 1. Engine overheating. 1. Check reason for overheating (NOT CAUSED BY IGNITION and repair as necessary.
SYSTEM). GAUGE MAY OR MAY 2. Freeze point of coolant not 2. Check coolant concentration.
NOT BE READING HIGH correct. Mixture is too rich or See DESCRIPTION, and
too lean. adjust ratio as required.
HOSE OR HOSES COLLAPSE 1. Vacuum created in cooling 1. (a) Radiator cap relief valve
WHILE ENGINE IS RUNNING system on engine cool-down is stuck. See DIAGNOSIS AND
not being relieved through TESTING. Replace if
coolant reserve/overflow necessary.
system. (b) Hose between coolantreserve/overflow tank and radiator is kinked. Repair as necessary. (c) Vent at coolant reserve/overflow tank is plugged. Clean vent and repair as necessary. (d) Reserve/overflow tank is internally blocked or plugged. Check for blockage and repair as necessary.
| INADEQUATE HEATER | 1. Has a Diagnostic Trouble | 1. Refer to EMISSIONS |
| PERFORMANCE. | Code (DTC) been set? | CONTROL |
| 2. Coolant level low. | 2. See DIAGNOSIS AND |
TESTING.
3. Obstructions in heater 3. Remove heater hoses at both
hose/fittings. ends and check for obstructions.
4. Heater hose kinked. 4. Locate kinked area and repairas necessary. 5. Water pump is not pumping 5. If a slipping belt is detected,
water to/through the heater see BELT-ACCESSORY core. When the engine is fully DRIVE. If heater core warmed up, both heater hoses obstruction is detected, see should be hot to the touch. If STANDARD PROCEDURE only one of the hoses is hot, the for cooling system reverse water pump may not be flushing. operating correctly or the heater core may be plugged. Accessory drive belt may be slipping causing poor water pump operation.
STEAM IS COMING FROM THE 1. During wet weather, moisture 1. Occasional steam emitting FRONT OF VEHICLE NEAR THE (snow, ice or rain condensation) from this area is normal. No GRILLE AREA WHEN WEATHER IS on the radiator or condenser repair is necessary. WET, ENGINE IS WARMED UP will evaporate when the
AND RUNNING, AND VEHICLE IS thermostat opens. This opening
STATIONARY. TEMPERATURE allows heated water into the GAUGE IS IN NORMAL RANGE radiator. When the moisture
contacts the hot radiator or condenser, steam may be emitted. This usually occurs in cold weather with no fan or airflow to blow it away.
COOLANT COLOR 1. Coolant color is not 1. See DESCRIPTION for
necessarily an indication of coolant concentration
adequate corrosion or information. Adjust coolanttemperature protection. Do not mixture as necessary. rely on coolant color for determining condition of coolant.
COOLANT LEVEL CHANGES IN 1. Level changes are to be 1. A normal condition. No COOLANT RESERVE/OVERFLOW expected as coolant volume repair is necessary.
TANK. TEMPERATURE GAUGE IS fluctuates with engine IN NORMAL RANGE temperature. If the level in the tank was between the FULL and ADD marks at normal operating temperature, the level should return to within that range after operation at elevated temperatures.
FAN RUNS ALL THE TIME 1. Fan control sensors 1. Check for DTCs. Verify
inoperative. sensor readings.2. Transmission temperature too 2. Check for transmission over high. temp DTC. 3. Engine coolant temperature 3. (a) Check coolant level. too high. Correct level as required. (b) Thermostat stuck. Replace
thermostat. (c) Water pump failed. Replace water pump. (d) Coolant flow restricted. Clean radiator. (e) Air flow over radiator obstructed. Remove obstruction. 4. ECM or TIPM defective. 4. Replace ECM or TIPM
CLEANING/REVERSE FLUSHING
CAUTION: The cooling system normally operates at 97-110 kPa (14-16 psi) pressure. Exceeding this pressure may damage the radiator or hoses.
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.
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.
CAUTION: Be sure instructions on the container are followed.
REVERSE FLUSHING ENGINE
Drain the cooling system. See STANDARD PROCEDURE. Remove the thermostat housing and thermostat.
Install the thermostat housing. Disconnect the radiator upper hose from the radiator and attach the flushing gun to the hose. Disconnect the radiator lower hose from the water pump. Attach a lead away hose to the water pump inlet fitting.
CAUTION: Be sure that the heater control valve is closed (heat off). This is done to prevent coolant flow with scale and other deposits from entering the heater core.
Connect the water supply hose and air supply hose to the flushing gun. Allow the engine to fill with water. When the engine is filled, apply air in short blasts, allowing the system to fill between air blasts. Continue until clean water flows through the lead away hose. For more information, refer to operating instructions supplied with flushing equipment.
Remove the lead away hose, flushing gun, water supply hose and air supply hose. Remove the thermostat housing. See REMOVAL. Install the thermostat and housing with a replacement gasket . See INSTALLATION. Connect the radiator hoses. Refill the cooling system with the correct antifreeze/water mixture . See STANDARD PROCEDURE.
DRAINING
1 - CYLINDER BLOCK DRAIN PLUG 2 - EXHAUST MANIFOLD AND HEAT SHIELD
WARNING: Do not remove the cylinder block drain plugs (1) or loosen the radiator draincock with system hot and under pressure. Serious burns from coolant can occur.
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 left/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.
FILLING-DIESEL
1. Tighten the radiator draincock and the cylinder block drain plug(s) (if removed).
CAUTION: Failure to purge air from the cooling system can result in an overheating condition and severe engine damage.
2. Fill cooling system with the antifreeze mixture. Refer to DESCRIPTION . Fill pressure bottle to service line and install cap.
NOTE: The engine cooling system will push any remaining air into the coolant bottle within about an hour of normal driving. As a result, a drop in coolant level in the pressure bottle may occur. If the engine cooling system overheats and pushes coolant into the overflow side of the coolant bottle, this coolant will be sucked back into the cooling system ONLY IF THE PRESSURE CAP IS LEFT ON THE BOTTLE. Removing the pressure cap breaks the vacuum path between the two bottle sections and the coolant will not return to cooling system.
3. With heater control unit in the HEAT position, operate engine with pressure bottle cap in place. 4. Add coolant to pressure bottle as necessary. Only add coolant to the pressure bottle when the engine is cold. Coolant level in a warm engine will be higher due to thermal expansion.
NOTE: The coolant bottle has two chambers. Coolant will normally only be in the outboard (larger) of the two. The inboard chamber is only to recover coolant in the event of an overheat or after a recent service fill. The inboard chamber should normally be empty. If there is coolant in the overflow side of the coolant bottle (after several warm/cold cycles of the engine) and coolant level is above cold full when cold, disconnect the end of the overflow hose at the fill neck and lower it into a clean container. Allow coolant to drain into the container until emptied. Reconnect overflow hose to fill neck.
DESCRIPTION SPECIFICATION
Metric US 3.7L 13.2L 14.0 qts.
| 4.0L | 13.2 L | 14.0 qts. |
| 2.8L Diesel | 12.5 L | 11.8 qts |
Torque
DESCRIPTION N.m Ft. Lbs. In. Lbs. Engine Air Tubes
| Turbocharger to Intercooler | 4.7 | - | 42 |
| Intercooler to Intake Manifold | 4.7 | - | 42 |
| Automatic Belt Tensioner to Mounting Bracket - 3.7L | 41 | 30 | - |
| Automatic Belt Tensioner Pulley Bolt - 3.7L | 61 | 45 | - |
| Accessory Drive Belt Idler Pulley Bolt - 2.8L Diesel | 53 | 39 | - |
| Accessory Drive Belt Tensioner Bolt - 2.8L Diesel | 47.1 | 35 | - |
| Viscous Fan Drive to Engine - 3.7L | 95 | 70 | - |
| Viscous Fan Drive to Engine - 2.8L Diesel | 149 | 110 | - |
| Cooling Fan Support Bolts | 47.1 | 35 | - |
| Block Heater Bolt - 3.7L | 2 | - | 17 |
| Transmission Oil/Condenser to Radiator Bolts | 11.9 | - | 105 |
| Coolant Pressure Bottle to Plenum mounting Bolts -3.7L | 8.5 | - | 75 |
only
| Electric Fan to Fan Shroud Bolts | 9 | - | 80 |
| Fan Blade Assy. to Viscous Drive Bolts - 3.7L/2.8L HD | 23.7 | - | 210 |
Cooling
| Fan Shroud to Radiator Mounting Bolts | 9 | - | 80 |
| Radiator Upper Isolator to Crossmember - Bolts | 10.7 | - | 95 |
| Thermostat Housing Bolts | - | - | - |
| 2.8L Diesel | 27.5 | 21 | - |
| 3.7L | 13 | - | 115 |
Water Pump Bolts
| 3.7L | 54 | 40 | - |
| Water Pump Housing Nuts - 2.8L Diesel | 24.4 | 18 | - |
CONDITION POSSIBLE CAUSES CORRECTION
| RIB CHUNKING (ONE OR | 1. Foreign objects imbedded in | 1. Remove foreign objects from |
| MORE RIBS HAS SEPARATED pulley grooves. | pulley grooves. Replace belt. | |
| FROM BELT BODY) | 2. Installation damage. | 2. Replace belt. |
| RIB OR BELT WEAR | 1. Pulley(s) misaligned. | 1. Align pulley(s). |
| 2. Abrasive environment. | 2. Clean pulley(s). Replace belt if |
necessary.
3. Rusted pulley(s). 3. Clean rust from pulley(s).
4. Sharp or jagged pulley groove 4. Replace pulley.tips.
5. Rubber deteriorated. 5. Replace belt. LONGITUDINAL BELT 1. Belt has mistracked from pulley 1. Replace belt. CRACKING (CRACKS groove. BETWEEN TWO RIBS) 2. Pulley groove tip has worn away 2. Replace belt.
rubber to tensile member.
BELT SLIPS 1. Belt slipping because of 1. Replace automatic belt
insufficient tension. tensioner.
2. Belt routed incorrectly. 2. Verify belt routing.
3. Incorrect belt. 3. Replace belt.
4. Belt or pulley subjected to 4. Replace belt and clean pulleys.substance (belt dressing, oil ethylene glycol) that has reduced friction.
5. Driven component bearing 5. Replace faulty component
failure. bearing.6. Belt glazed and hardened from 6. Replace belt. heat and excessive slippage.
| "GROOVE JUMPING" (BELT | 1. Belt tension either too high or 1. Replace automatic belt | |
| DOES NOT MAINTAIN | too low. | tensioner. |
| CORRECT POSITION ON | 2. Belt routed incorrectly. | 2. Verify belt routing. |
| PULLEY) | 3. Incorrect belt. | 3. Replace belt. |
| 4. Pulley(s) not within design | 4. Replace pulley(s). |
tolerance. 5. Foreign object(s) in grooves. 5. Remove foreign objects from grooves.
6. Pulley misalignment. 6. Check and replace.
7. Belt cord line is broken. 7. Replace belt.
BELT BROKEN (NOTE: 1. Excessive tension. 1. Replace belt and automatic belt
IDENTIFY AND CORRECT tensioner.
PROBLEM BEFORE NEW 2. Incorrect belt. 2. Replace belt.
BELT IS INSTALLED) 3. Tensile member damaged during 3. Replace belt.belt installation.
4. Severe misalignment. 4. Check and replace.
5. Bracket, pulley, or bearing 5. Replace defective component
failure. and belt.
NOISE (OBJECTIONABLE 1. Belt slippage. 1. Replace belt or automatic belt| SQUEAL, SQUEAK, OR | tensioner. | |
| RUMBLE IS HEARD OR FELT 2. Bearing noise. | 2. Locate and repair. | |
| WHILE DRIVE BELT IS IN | 3. Belt misalignment. | 3. Replace belt. |
| OPERATION) | 4. Belt-to-pulley mismatch. | 4. Install correct belt. |
HOSES-COOLING SYSTEM-2.8L DIESEL
Removal
1
Drain cooling system. See STANDARD PROCEDURE.
2
Remove engine cover from engine. Refer to REMOVAL .
3
Disconnect heater core supply line at heater core and viscous heater. Remove hose from vehicle.
4
Disconnect heater core return line (5) from heater core and EGR cooler. Remove hose from vehicle.
REMOVAL-UPPER HOSE-2.8L DIESEL
1 - FAN SHROUD 2 - HOSE CLAMP 3 - UPPER RADIATOR HOSE 4 - THERMOSTAT HOUSING
1. Drain cooling system. See STANDARD PROCEDURE. 2. Disconnect upper radiator hose (3) from thermostat housing. 3. Disconnect upper radiator hose from radiator and remove from vehicle.
Installation
1
Connect heater core supply hose to heater core and viscous heater. Position hose clamps into proper
position.
2
Connect heater core return hose to heater core and EGR cooler. Position hose clamps into proper position.
3
Install engine cover to engine. Refer to INSTALLATION .
4
Refill cooling system. See STANDARD PROCEDURE.
INSTALLATION-UPPER HOSE-2.8L DIESEL
1 - FAN SHROUD 2 - HOSE CLAMP 3 - UPPER RADIATOR HOSE 4 - THERMOSTAT HOUSING
1. Install upper radiator hose on radiator and thermostat housing. 2. Reposition hose clamps in proper position. 3. Refill cooling system to proper level. See STANDARD PROCEDURE.
COOLER-TRANSMISSION
Description
The automatic transmission cooler is located in the front of the condenser and behind the front fascia. The transmission cooler is a heat exchanger that allows heat in the transmission fluid to be transferred to the air passing over the cooler fins.
The transmission oil cooler for the 2.8L Diesel with automatic transmission integrated into the A/C condenser.
The Transmission oil cooler assembly is equipped with quick connect fitting for the transmission oil cooler lines.
TRANSMISSION OIL COOLER-REMOVAL
1. Remove electric cooling fan. See REMOVAL. 2. Position cooling fan out of the way. 3. Remove the transmission cooler line retaining block nut. 4. Remove transmission cooler lines from transmission lines. 5. Using Release Tool 8875A, disconnect transmission cooler tube from the transmission, see STANDARD
PROCEDURE.
6. Remove the transmission cooler mounting bolts. 7. Remove transmission cooler from vehicle.
TRANSMISSION OIL COOLER-INSTALLATION
1. Position transmission cooler in vehicle. 2. Install transmission mounting bolts. Tighten to 14 N.m (123 in. lbs.) 3. Install transmission cooler lines into transmission, see STANDARD PROCEDURE. 4. Install locking plate and nut. Tighten nut to 22.5 N.m (200 in. lbs.) 5. Install electric cooling fan. See INSTALLATION.
LINES-TRANSMISSION COOLER
DISCONNECT
1 - QUICK CONNECT FITTING
2 - DUST CAP 3 - OIL COOLER LINE 4 - SPECIAL TOOL 8875A
1. Remove dust cap by pulling it straight back off of quick connect fitting (1). 2. Place properly sized Release Tool (4) onto transmission cooler line with the fingers of the tool facing the quick connect fitting. 3. Slide Release Tool down the transmission line and engage the fingers of the tool into the retaining clip. When properly engaged in the clip, the tool will fit flush against the quick connect fitting. 4. Rotate the release tool 60° to expand the retaining clip. 5. While holding the release tool against the quick connect fitting, pull back on the transmission cooler line to remove. 6. If quick connect fitting is damaged or leaking at transmission oil cooler or transmission, remove fitting.
CONNECT
1 - QUICK CONNECT FITTING 2 - CLIP 3 - OIL COOLER LINE 4 - DUST CAP
1. If removed, install quick connect fitting into transmission oil cooler or transmission. Tighten fitting to 15 N.m (132 in. lbs.). 2. Align transmission cooler line (3) with quick connect fitting while pushing straight into the fitting. 3. Push in on transmission cooler line until a "click" is heard or felt. 4. Slide dust cap (4) down the transmission cooler line and snap it over the quick connect fitting until it is fully seated and rotates freely. Dust cap will only snap over quick connect fitting when the transmission cooler line is properly installed.
NOTE: If dust cap will not snap into place, repeat assembly step #2.
