Intermittent
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .
Engine Overheated Indicator Always On
| Step | Action | Yes | No |
|---|---|---|---|
| DEFINITION: The Engine Hot indicator is always ON. | |||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Start the engine. Does the Check Gages indicator illuminate? | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections |
| 3 | Install a scan tool. With the scan tool, observe the ECT Sensor parameter in the powertrain control module (PCM) data list. Does the scan tool indicate that the ECT Sensor parameter is within the temperature range shown on the temperature gage? | Go to Engine Overheating | Go to Step 4 |
| 4 | Replace the instrument panel cluster (IPC). Refer to Instrument Cluster Replacement (Left Hand Drive) or Instrument Cluster Replacement (Right Hand Drive) . Did you complete the replacement? | Go to Step 5 | |
| 5 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
Engine Overheated Indicator Always On
Loss of Coolant
| Step | Action | Yes | No |
|---|---|---|---|
| DEFINITION: The cooling system is loosing coolant either internally or externally. | |||
| 1 | Were you sent here from Symptoms or another diagnostic table? | Go to Step 2 | Go to Symptoms - Engine Cooling |
| 2 | Repair any present DTCs. Refer to Diagnostic System Check - Vehicle . Is the action complete? | Go to Step 3 | |
| 3 | Inspect the coolant level. Is the coolant at the proper level? | Go to Step 6 | Go to Step 4 |
| 4 | Fill the cooling system to the proper level. Refer to Cooling System Draining and Filling (Static Fill) or Cooling System Draining and Filling (Vac-N-Fill) . Is the action complete? | Go to Step 5 | |
| 5 | If the engine is suspected to have a coolant leak into a cylinder, the coolant can hydraulically lock the engine. Does the engine crankshaft rotate? | Go to Step 6 | Go to Step 28 |
| 6 | Engine overheating can cause a loss of coolant. Is the engine overheating? | Go to Step 29 | Go to Step 7 |
| 7 | Extended operation with a low coolant level can cause engine internal component failure. Is the engine knocking? | Go to Step 31 | Go to Step 8 |
| 8 | Idle the engine at normal operating temperature. Inspect for heavy white smoke coming out of the exhaust pipe. Is a heavy white smoke present from the exhaust pipe? | Go to Step 9 | Go to Step 10 |
| 9 | Coolant in the exhaust system creates a distinctive, burning coolant odor in the exhaust. Condensation in the exhaust system can cause an odorless white smoke during engine warm up. Does the white smoke have a burning coolant type odor? | Go to Step 30 | Go to Step 10 |
| 10 | With the engine idling, inspect the coolant recovery system. Does the coolant recovery system discharge coolant while the engine is idling? | Go to Step 15 | Go to Step 11 |
| 11 | Visually inspect the hoses, pipes and hose clamps at the following locations: Coolant reservoir Heater core Radiator Are any of the hoses, clamps or pipes leaking? | Go to Step 20 | Go to Step 12 |
| 12 | Visually inspect the following components: Block heater Coolant pressure cap Core plugs Cylinder head gaskets Engine block Intake manifold Radiator Thermostat housing Water pump Are any of the listed components leaking? | Go to Step 20 | Go to Step 13 |
| 13 | Pressure test the cooling system. Refer to Cooling System Leak Testing . With the cooling system pressurized, visually inspect the components listed in steps 11 and 12. Are any leaks present? | Go to Step 20 | Go to Step 14 |
| 14 | Pressure test the coolant pressure cap. Refer to Pressure Cap Testing . Does the coolant pressure cap hold pressure? | Go to Step 16 | Go to Step 21 |
| 15 | Pressure test the coolant pressure cap. Refer to Pressure Cap Testing . Does the coolant pressure cap hold pressure? | Go to Step 32 | Go to Step 21 |
| 16 | Inspect for the following conditions: A coolant smell inside of the vehicle Coolant in the HVAC module drain tube Coolant on the vehicle floor covering near the HVAC module Is coolant present? | Go to Step 22 | Go to Step 17 |
| 17 | Inspect the underside of the engine oil fill cap for a gray/white milky substance. Is there a milky substance under the oil fill cap? | Go to Step 18 | Go to Step 19 |
| 18 | Inspect the engine oil fluid level indicator for a gray/white milky substance. Is there a milky substance on the engine oil fluid level indicator? | Go to Step 23 | Go to Step 19 |
| 19 | Inspect the automatic transmission oil fluid level indicator, if equipped, for a gray/white milky substance. Is there a milky substance on the automatic transmission fluid level indicator? | Go to Step 25 | Go to Step 33 |
| 20 | Repair or replace the leaking component. Refer to the appropriate repair. Is the repair complete? | Go to Step 33 | |
| 21 | Replace the coolant pressure cap. Is the repair complete? | Go to Step 33 | |
| 22 | Replace the heater core. Refer to Heater Core Replacement (Left Hand Drive) or Heater Core Replacement (Right Hand Drive) . Is the repair complete? | Go to Step 33 | |
| 23 | Remove the engine oil cooler lines from the radiator. Pressure test the cooling system. Refer to Cooling System Leak Testing . Inspect the engine oil cooler for coolant. Is coolant present? | Go to Step 24 | Go to Step 27 |
| 24 | Replace the radiator. Refer to Radiator Replacement . Service the engine oil and filter. Refer to Engine Oil and Oil Filter Replacement . Is the repair complete? | Go to Step 33 | |
| 25 | Remove the transmission oil cooler lines from the radiator. Pressure test the cooling system. Refer to Cooling System Leak Testing . Inspect the transmission oil cooler for coolant. Is coolant present? | Go to Step 26 | Go to Step 27 |
| 26 | Replace the radiator. Refer to Radiator Replacement . Service the automatic transmission. Refer to Engine Coolant/Water in Transmission . Is the repair complete? | Go to Step 33 | |
| 27 | Install the cooler lines to the radiator. Is the action complete? | Go to Step 33 | |
| 28 | Repair the engine no crank condition. Refer to Engine Will Not Crank - Crankshaft Will Not Rotate . Is the repair complete? | Go to Step 33 | |
| 29 | Repair the engine overheating condition. Refer to Engine Overheating . Is the repair complete? | Go to Step 33 | |
| 30 | Repair the engine internal coolant leak. Refer to Coolant in Engine Oil . Is the repair complete? | Go to Step 33 | |
| 31 | Repair the engine knock. Refer to Lower Engine Noise, Regardless of Engine Speed . Is the repair complete? | Go to Step 33 | |
| 32 | Repair the combustion pressure in the cooling system problem. Refer to Cylinder Leakage Test . Is the repair complete? | Go to Step 33 | |
| 33 | Operate the system in order to verify the repair. Did you find and correct the condition? | System OK | Go to Step 2 |
Loss of Coolant
Scheme 10
The coolant thermostat can be tested using a temperature (tempil) stick. The temperature stick is a pencil like device. It has a wax material containing certain chemicals which melt at a given temperature. Temperature sticks can be used to determine a thermostat's operating range, by rubbing 87°C (188°F) and 97°C (206°F) sticks on the thermostat housing (4).
Tools Required
J 24731 Tempilstick. See Special Tools .
- Use a tempilstick in order to find the opening and the closing temperatures of the coolant thermostat. J 24731-188 tempilstick melts at 87°C (188°F). The thermostat should begin to open at 90°C (194°F). J 24731-206 tempilstick melts at 97°C (206°F). The thermostat should be fully open at 107°C (225°F).
- Replace the coolant thermostat if it does not operate properly between this temperature range. Refer to «Engine Coolant Thermostat Replacement»(ref-266906-S00133521822007100900000) .
Coolant Heater Inoperative
| Step | Action | Yes | No |
|---|---|---|---|
| DEFINITION: The Engine Hot indicator is always ON. | |||
| 1 | Did you perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Engine Cooling |
| 2 | Test the engine coolant heater power supply cord for an open or short to ground. Refer to Circuit Testing . Did you find a condition? | Go to Step 3 | Go to Step 4 |
| 3 | Replace the engine coolant heater power supply cord. Refer to Coolant Heater Cord Replacement . Did you complete the repair? | Go to Step 6 | |
| 4 | Inspect for poor connections at the harness connector of the engine coolant heater. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 6 | Go to Step 5 |
| 5 | Replace the engine coolant heater. Refer to Coolant Heater Replacement . Did you complete the repair? | Go to Step 6 | |
| 6 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
Coolant Heater Inoperative
J 24460-01 Cooling System Pressure Tester. See Special Tools .
J 24460-01 Cooling System Pressure Tester. See Special Tools .
- J 26568 Coolant and Battery Tester. See «Special Tools»(ref-266906-S08992574552007100900000) .
- J 38185 Hose Clamp Pliers.
Filling Procedure
Note. The procedure below must be followed. Improper coolant level could result in a low or high coolant level condition, causing engine damage.
- If a complete block drain was required, install the coolant heater. Refer to «Coolant Heater Replacement»(ref-266906-S05068408192007100900000) .
- Install the lower radiator hose.
- Using the J 38185 slide the lower radiator hose clamp into the original position. See «Special Tools»(ref-266906-S08992574552007100900000) .
- Lower the vehicle.
- Install the radiator cap.
- Remove coolant recovery reservoir cap.
- Fill the coolant recovery reservoir with the remaining coolant.
- Install coolant recovery reservoir cap.
- Start the engine.
- Run the engine at 2,000-2,500 RPM until the engine reaches normal operating temperature.
- Allow the engine to idle for 3 minutes.
- Shut the engine off.
- Allow the engine to cool.
- Top off the coolant recovery reservoir as necessary.
- Inspect the cooling system for leaks.
- Rinse away any excess coolant from the engine and the engine compartment.
- Inspect the concentration of the engine coolant using J 26568 . See «Special Tools»(ref-266906-S08992574552007100900000) .
- J 26568 Coolant and Battery Tester. See «Special Tools»(ref-266906-S08992574552007100900000) .
- J 38185 Hose Clamp Pliers. See «Special Tools»(ref-266906-S08992574552007100900000) .
- GE-47716 Vac-N-Fill Coolant Refill Tool. See «Special Tools»(ref-266906-S08992574552007100900000) .
- J 42401 Radiator Cap and Surge Tank Test Adapter. See «Special Tools»(ref-266906-S08992574552007100900000) .
Radiator Cleaning
| CAUTION | NEVER spray water on a hot radiator. The resulting steam could cause personal injury. |
Note. The radiator fins are necessary for good heat transfer. Do not brush the fins. This may cause damage to the fins, reducing heat transfer.
- Some conditions may require the use of warm water and a mild detergent.
- Clean the A/C condenser fins.
- Clean between the A/C condenser and radiator.
- Clean the radiator cooling fins.
- Straighten any damaged cooling fins.
Scheme 11
| Callout | Component Name |
|---|---|
| NOTE: Refer to Fastener Notice . Fastener Tightening Specifications: Refer to Fastener Tightening Specifications . Preliminary Procedure Drain the cooling system. Refer to Cooling System Draining and Filling (Static Fill) or Cooling System Draining and Filling (Vac-N-Fill) . Remove the air cleaner assembly. Refer to Air Cleaner Assembly Replacement . | |
| 1 | Coolant Reservoir Bolt Tip: Remove the coolant reservoir hoses from the coolant reservoir. Tighten: 10 N.m (89 lb in) |
| 2 | Coolant Reservoir |
| NOTE |
|---|
| Refer to Fastener Notice . |
Coolant Recovery Reservoir Replacement (Left Hand Drive)
Scheme 12
| Callout | Component Name |
|---|---|
| Preliminary Procedure Drain the cooling system. Refer to Cooling System Draining and Filling (Static Fill) or Cooling System Draining and Filling (Vac-N-Fill) . Remove the air cleaner assembly. Refer to Air Cleaner Assembly Replacement . | |
| 1 | Coolant Reservoir Bolt (Qty: 2) NOTE: Refer to Fastener Notice . Tip: Remove the coolant reservoir hoses from the coolant reservoir. Tighten: 10 N.m (89 lb in) |
| 2 | Coolant Reservoir |
| NOTE |
|---|
| Refer to Fastener Notice . |
Coolant Recovery Reservoir Replacement (Right Hand Drive)
Scheme 13
| Callout | Component Name |
|---|---|
| Fastener Tightening Specifications: Refer to Fastener Tightening Specifications . Preliminary Procedure: Drain the cooling system. Refer to Cooling System Draining and Filling (Static Fill) or Cooling System Draining and Filling (Vac-N-Fill) . | |
| 1 | Radiator Inlet Hose Tip: Use J 38185 to release the radiator hose clamps. See Special Tools . |
Radiator Inlet Hose Replacement (LLR)
Scheme 14
| Callout | Component Name |
|---|---|
| Fastener Tightening Specifications: Refer to Fastener Tightening Specifications . Preliminary Procedure Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle . Drain the cooling system. Refer to Cooling System Draining and Filling (Static Fill) or Cooling System Draining and Filling (Vac-N-Fill) . Remove the left front wheelhouse panel. Refer to Wheelhouse Panel Replacement (Front) or Wheelhouse Panel Replacement (Rear) . Remove the engine shield. Refer to Engine Shield Replacement . | |
| 1 | Radiator Outlet Hose Tip: Use J 38185 to release the radiator hose clamps. See Special Tools . |
Radiator Outlet Hose Replacement (LLR)
Scheme 15
| Callout | Component Name |
|---|---|
| Fastener Tightening Specifications: Refer to Fastener Tightening Specifications . Preliminary Procedure: Drain the cooling system. Refer to Cooling System Draining and Filling (Static Fill) or Cooling System Draining and Filling (Vac-N-Fill) . | |
| 1 | Radiator Inlet Vent Hose Tip: Note routing of radiator inlet vent hose for proper installation. |
Radiator Vent Inlet Hose Replacement (Left Hand Drive)
Scheme 16
| Callout | Component Name |
|---|---|
| Preliminary Procedure Drain the cooling system. Refer to Cooling System Draining and Filling (Static Fill) or Cooling System Draining and Filling (Vac-N-Fill) . Remove the air cleaner assembly. Refer to Air Cleaner Assembly Replacement . | |
| 1 | Radiator Inlet Vent Hose |
Radiator Vent Inlet Hose Replacement (Right Hand Drive)
- J 41240 Fan Clutch Remover and Installer. See «Special Tools»(ref-266906-S08992574552007100900000) .
- J 46406 Fan Clutch Remover and Installer. See «Special Tools»(ref-266906-S08992574552007100900000) .
J 38185 Hose Clamp Pliers. See Special Tools .
J 38185 Hose Clamp Pliers. See Special Tools .
Tool Required
J 46406 Fan Clutch Remover and Installer. See Special Tools .
J 38185 Hose Clamp Pliers. See Special Tools .
Coolant Heater
The optional engine coolant heater (RPO K05) operates using 110-volt AC external power and is designed to warm the coolant in the engine block area for improved starting in very cold weather -29°C (-20°F). The coolant heater helps reduce fuel consumption when a cold engine is warming up. The unit is equipped with a detachable AC power cord. A weather shield on the cord is provided to protect the plug when not in use.
Cooling System
The cooling systems function is to maintain an efficient engine operating temperature during all engine speeds and operating conditions. The cooling system is designed to remove approximately one-third of the heat produced by the burning of the air-fuel mixture. When the engine is cold, the coolant does not flow to the radiator until the thermostat opens. This allows the engine to warm quickly.
Cooling Cycle
Coolant flows from the radiator outlet and into the water pump inlet. Some coolant flows from the water pump, to the heater core, then back to the water pump. This provides the passenger compartment with heat and defrost capability as the coolant warms up.
Coolant also flows from the water pump outlet and into the engine block. In the engine block, the coolant circulates through the water jackets surrounding the cylinders where it absorbs heat.
The coolant then flows through the cylinder head gasket openings and into the cylinder heads. In the cylinder heads, the coolant flows through the water jackets surrounding the combustion chambers and valve seats, where it absorbs additional heat.
From the cylinder heads, the coolant flows to the thermostat. The flow of coolant will either be stopped at the thermostat until the engine reaches normal operating temperature or it will flow through the thermostat and into the radiator where it is cooled. At this point, the coolant flow cycle is completed.
Efficient operation of the cooling system requires proper functioning of all cooling system components. The cooling system consists of the following components
Coolant
The engine coolant is a solution made up of a 50-50 mixture of DEX-COOL and suitable drinking water. The coolant solution carries excess heat away from the engine to the radiator, where the heat is dissipated to the atmosphere.
Radiator
The radiator is a heat exchanger. It consists of a core and 2 tanks. The aluminum core is a tube and fin crossflow design that extends from the inlet tank to the outlet tank. Fins are placed around the outside of the tubes to improve heat transfer to the atmosphere.
The inlet and outlet tanks are a molded, high temperature, nylon reinforced plastic material. A high temperature rubber gasket seals the tank flange edge to the aluminum core. The tanks are clamped to the core with clinch tabs. The tabs are part of the aluminum header at each end of the core.
The radiator also has a drain cock located in the bottom of the left hand tank. The drain cock unit includes the drain cock and drain cock seal.
The radiator removes heat from the coolant passing through it. The fins on the core transfer heat from the coolant passing through the tubes. As air passes between the fins, it absorbs heat and cools the coolant.
Pressure Cap
The pressure cap seals the cooling system. It contains a blow off or pressure valve and a vacuum or atmospheric valve. The pressure valve is held against its seat by a spring, which protects the radiator from excessive cooling system pressure. The vacuum valve is held against its seat by a spring, which permits opening of the valve to relieve vacuum created in the cooling system as it cools off. The vacuum, if not relieved, might cause the radiator and/or coolant hoses to collapse.
The pressure cap allows cooling system pressure to build up as the temperature increases. As the pressure builds, the boiling point of the coolant increases. Engine coolant can be safely run at a temperature much higher than the boiling point of the coolant at atmospheric pressure. The hotter the coolant is, the faster the heat transfers from the radiator to the cooler, passing air.
The pressure in the cooling system can get too high. When the cooling system pressure exceeds the rating of the pressure cap, it raises the pressure valve, venting the excess pressure.
As the engine cools down, the temperature of the coolant drops and a vacuum is created in the cooling system. This vacuum causes the vacuum valve to open, allowing outside air into the surge tank. This equalizes the pressure in the cooling system with atmospheric pressure, preventing the radiator and coolant hoses from collapsing.
Coolant Recovery System
The coolant recovery system consists of a plastic coolant recovery reservoir and overflow tube. The recovery reservoir is also called a recovery tank or expansion tank. It is partially filled with coolant and is connected to the radiator fill neck with the overflow tube. Coolant can flow back and forth between the radiator and the reservoir.
In effect, a cooling system with a coolant recovery reservoir is a closed system. When the pressure in the cooling system gets too high, it will open the pressure valve in the pressure cap. This allows the coolant, which has expanded due to being heated, to flow through the overflow tube and into the recovery reservoir. As the engine cools down, the temperature of the coolant drops and a vacuum is created in the cooling system. This vacuum opens the vacuum valve in the pressure cap, allowing some of the coolant in the reservoir to be siphoned back into the radiator. Under normal operating conditions, no coolant is lost. Although the coolant level in the recovery reservoir goes up and down, the radiator and cooling system are kept full. An advantage to using a coolant recovery reservoir is that it eliminates almost all air bubbles from the cooling system. Coolant without bubbles absorbs heat much better than coolant with bubbles.
Cooling Fan and Clutch
The engine cooling fan and clutch are driven by the crankshaft via the drive belt. The cooling fan draws air through the radiator to improve the transfer of heat from the coolant to the atmosphere. As the fan blades spin, they pull cool, outside air past the radiator core. The fan clutch drives the cooling fan. The fan clutch controls the amount of torque that is transmitted from the crankshaft to the fan blades. The clutch allows more torque to engage on the fan when the engine operating temperature increases and/or the vehicle speed is low. As the torque increases, the fan turns more quickly. The fan clutch decreases the torque applied to the cooling fan when the engine temperature decreases and/or the vehicle speed is high. As the torque decreases, the fan speed decreases.
Air Baffles and Seals
The cooling system uses deflectors, air baffles and air seals to increase cooling system capability. Deflectors are installed under the vehicle to redirect airflow beneath the vehicle and through the radiator to increase engine cooling. Air baffles are also used to direct airflow through the radiator and increase cooling capability. Air seals prevent air from bypassing the radiator and A/C condenser and prevent recirculation of hot air for better hot weather cooling and A/C condenser performance.
Water Pump
The water pump is a centrifugal vane impeller type pump. The pump consists of a housing with coolant inlet and outlet passages and an impeller. The impeller is mounted on the pump shaft and consists of a series of flat or curved blades or vanes on a flat plate. When the impeller rotates, the coolant between the vanes is thrown outward by centrifugal force.
The impeller shaft is supported by one or more sealed bearings. The sealed bearings never need to be lubricated. Grease cannot leak out, dirt and water cannot get in as long as the seal is not damaged or worn.
The purpose of the water pump is to circulate coolant throughout the cooling system. The water pump is driven by the crankshaft via the drive belt.
Thermostat
The thermostat is a coolant flow control component. Its purpose is to help regulate the operating temperature of the engine. It utilizes a temperature sensitive wax-pellet element. The element connects to a valve through a small piston. When the element is heated, it expands and exerts pressure against the small piston. This pressure forces the valve to open. As the element is cooled, it contracts. This contraction allows a spring to push the valve closed.
When the coolant temperature is below the rated thermostat opening temperature, the thermostat valve remains closed. This prevents circulation of the coolant to the radiator and allows the engine to warm up. After the coolant temperature reaches the rated thermostat opening temperature, the thermostat valve will open. The coolant is then allowed to circulate through the thermostat to the radiator where the engine heat is dissipated to the atmosphere. The thermostat also provides a restriction in the cooling system, after it has opened. This restriction creates a pressure difference which prevents cavitation at the water pump and forces coolant to circulate through the engine block.
Transmission Oil Cooler
The transmission oil cooler is a heat exchanger. It is located inside the right side end tank of the radiator. The transmission fluid temperature is regulated by the temperature of the engine coolant in the radiator.
The transmission oil pump, pumps the fluid through the transmission oil cooler line to the transmission oil cooler. The fluid then flows through the cooler where the engine coolant absorbs heat from the fluid. The fluid is then pumped through the transmission oil cooler return line, to the transmission.