Contents Section: Cooling System (mechanical) All sections

Engine Cooling System Chevrolet Monte Carlo VI

Cooling System (mechanical) 5 illustrations ~9486 words

Fastener Tightening Specifications

ApplicationSpecification
MetricEnglish
Coolant Recovery Reservoir Mounting Nut3.3 N.m29 lb in
Cooling Fan Shroud Bolt10 N.m89 lb in
Coolant Heater Bolt2 N.m18 lb in
Drive Belt Shield Bolt10 N.m89 lb in
Engine Block Coolant Drain Plug19 N.m14 lb ft
Engine Block Heater Screw2 N.m18 lb in
Knock Sensor19 N.m14 lb ft
Radiator Bracket Mounting Bolt10 N.m89 lb in
Radiator Lower Air Deflector20 N.m15 lb ft
Thermostat Bypass Pipe Bolt11 N.m98 lb in
Thermostat Bypass Pipe Nut25 N.m18 lb ft
Water Outlet Housing Bolt 3.4L25 N.m18 lb ft
Water Outlet Housing Bolt/Stud 3.8L27 N.m20 lb ft
Water Pump Bolt 3.4L10 N.m89 lb in
Water Pump Bolt (Long) 3.8L34 N.m25 lb ft
Water Pump Bolt (Short) 3.8L22 N.m16 lb ft
Water Pump Pulley Bolt 3.4L25 N.m18 lb ft
Water Pump Pulley Bolt 3.8L13 N.m115 lb in

Fastener Tightening Specifications

Scheme 1

Scheme 1: Engine Cooling Schematics

Scheme 2

Scheme 2: Cooling System Component Views
CalloutComponent Name
1Cooling Fan-Right
2Cooling Fan-Left

Cooling System Connector End Views

Cooling Fan - Left Connector End Connector Part Information 12033769 2-Way F Metri-Pack 630 Series, Pull to Seat (BLK) Pin Wire Color Circuit No. Function A BLK 250 Ground B LT BLU 409 Cooling Fan Motor Supply Voltage

Cooling Fan - Right Connector End Connector Part Information 12033769 2-Way F Metri-Pack 630 Series, Pull to Seat (BLK) Pin Wire Color Circuit No. Function A WHT 504 Cooling Fan Low Reference B GRY 532 Cooling Fan Motor Supply Voltage

Diagnostic Starting Point - Engine Cooling

Begin the system diagnosis with the Diagnostic System Check - Engine Cooling . The Diagnostic System Check will provide the following information

  1. The identification of the control module(s) which command the system
  2. The ability of the control module(s) to communicate through the serial data circuit
  3. The identification of any stored diagnostic trouble codes (DTCs) and their status

The use of the Diagnostic System Check will identify the correct procedure for diagnosing the system and where the procedure is located.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. 2: Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.
  2. 3: Determine if the Instrument Cluster or Powertrain Control Modules have set DTCs which may affect Engine Cooling operation are present.
  3. 4: The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.
StepActionYesNo
1Install a scan tool. Does the scan tool power up?Go to Step 2Go to Scan Tool Does Not Power Up in Data Link Communications
2Turn ON the ignition, with the engine OFF. Attempt to establish communication with the following control modules: Instrument Cluster Powertrain Control Module Does the scan tool communicate with the control modules?Go to Step 3Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications
3Select the powertrain control module display DTCs function on the scan tool. Does the scan tool display any DTCs?Go to Step 4Go to Symptoms - Engine Cooling
4Does the scan tool display any DTCs which begin with a "U"?Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link CommunicationsGo to Diagnostic Trouble Code (DTC) List

Diagnostic System Check - Engine Cooling

Scan Tool Output Controls

Scan Tool Output ControlAdditional Menu SelectionsDescription
Fans Low SpeedFan RelaysThe scan tool displays a Commanded State of None, Off or On. This allows you to communicate with the PCM and activate or deactivate the cooling fan 1 relay, manually turning the low speed fans On and Off.
Fans High SpeedFan RelaysThe scan tool displays a Commanded State of None, Off or On. This allows you to communicate with the PCM to activate or deactivate the cooling fan 1 relay, manually turning the low speed fans On. After a 3 second delay the PCM will activate the cooling fan 2 relay and the cooling fan 3 relay. This turns the high speed fans On and Off.

Powertrain Control Module (PCM) Scan Tool Output Controls

Scan Tool Data List

Scan Tool ParameterData ListUnits DisplayedTypical Data Value
Ignition Switch in RUN/Engine running/Automatic Transmission in PARK/Air Conditioner is OFF
ECT SensorEng 1, 2, EGR, EVAP, Cat, HO2S, Misfire, AIR°C/°FVaries
FC Relay 1 CommandEng 2On/OffVaries
FC Relay 2 and 3 CommandEng 2On/OffVaries
FC Relay 1 Circuit StatusODMFault/OKOK
FC Relay 2 and 3 Circuit StatusODMFault/OKOK

Powertrain Control Module (PCM) Scan Tool Data List (3.4 Liter LA1)

Scan Tool ParameterData ListUnits DisplayedTypical Data Value
Ignition Switch in RUN/Engine running/Automatic Transmission in PARK/Air Conditioner is OFF
ECT SensorEng 1, 2, EGR, EVAP, Cat, HO2S, Misfire, AIR°C/°FVaries
FC Relay 1 CommandENG2, CatOn/OffVaries
FC Relay 2 and 3 CommandENG2, CatOn/OffVaries
FC Relay 1 Circuit StatusODDFault/OKOK
FC Relay 2 and 3 Circuit StatusODDFault/OKOK

Powertrain Control Module (PCM) Scan Tool Data List (3.8 Liter L36)

Diagnostic Trouble Code (DTC) List

DTCDiagnostic ProcedureModule(s)
P0480DTC P0480 or P0481PCM
P0481DTC P0480 or P0481PCM

Diagnostic Trouble Code (DTC) List

Circuit Description

  1. P0480 - low speed cooling fan relay control circuit.
  2. P0481 - high speed cooling fan relay control circuit.

Battery positive voltage is supplied to the FAN CONT #1 relay from the FAN CONT #1 fuse. The powertrain control module (PCM) controls the FAN CONT #1 relay by grounding the low speed cooling fan relay control circuit through an internal solid state device called a driver.

Battery positive voltage is supplied to the FAN CONT #2 relay and the FAN CONT #3 relay from the FAN CONT #2 and FAN CONT #3 fuse. The PCM controls the relays by grounding the high speed cooling fan relay control circuit.

When the PCM is commanding a relay on, the voltage potential of the control circuit should be low, near 0 volts. When the PCM is commanding the control circuit to a relay, the voltage potential of the circuit should be high, near battery voltage. If the fault detection circuit senses a voltage other than what is expected, the DTC will set.

The PCM will monitor the control circuit for the following

  1. A short to ground
  2. A short to voltage
  3. An open circuit
  4. An open relay coil
  5. An internally shorted or excessively low resistance relay coil

When the PCM detects any of the above conditions, the DTC will set and the affected driver will be disabled.

Conditions for Running the DTC

  1. The ignition is ON.
  2. System voltage is between 9-18 volts.
  3. The relay control circuit is transitioned from OFF to ON or ON to OFF.

Conditions for Setting the DTC

  1. An improper voltage level has been detected on the cooling fan relay control circuit.
  2. The above conditions are present for at least 30 seconds.

Action Taken When the DTC Sets

  1. The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
  2. The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.

Conditions for Clearing the MIL/DTC

  1. The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed.
  2. The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
  3. The DTC can be cleared by using the scan tool.

Diagnostic Aids

  1. If the condition is not present, refer to «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/monte-carlo/vi-1999-2007/remont/body-electrical/#wiring-systems-introduction__testing-for-intermittent-conditions-and-poor) in Wiring Systems.
  2. Review the Freeze/Failure Records vehicle mileage since the diagnostic test last failed. This may help determine how often the condition that caused the DTC to be set occurs.

The numbers below refer to the step numbers on the diagnostic table.

  1. 2: Listen for an audible click when the FAN CONT #1 relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
  2. 3: Listen for an audible click when the FAN CONT #2 and FAN CONT #3 relays operate. Command both the ON and OFF states. Repeat the commands as necessary.
  3. 4: Tests for voltage at the coil side of the FAN CONT #1 relay. The FAN CONT #1 fuse supplies battery positive voltage to the coil side of the FAN CONT #1 relay.
StepActionYesNo
Schematic Reference: Engine Cooling Schematics Connector End View Reference: Cooling System Connector End Views
1Did you perform the Engine Cooling Diagnostic System Check?Go to Step 2Go to Diagnostic System Check - Engine Cooling
2Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the Fans Low Speed ON and OFF. Does the FAN CONT #1 relay turn ON and OFF with each command?Go to Step 3Go to Step 4
3With a scan tool, command the Fans High Speed ON and OFF. Do the FAN CONT #2 and the FAN CONT #3 relays turn ON and OFF with each command?Go to Diagnostic AidsGo to Step 6
4Turn OFF the ignition. Disconnect the FAN CONT #1 relay. Turn ON the ignition, with the engine OFF. Probe the battery positive voltage circuit of the FAN CONT #1 relay with a test lamp that is connected to a good ground. Does the test lamp illuminate?Go to Step 5Go to Step 16
5Connect a test lamp between the control circuit of the FAN CONT #1 relay and the battery positive voltage circuit of the FAN CONT #1 relay. With a scan tool, command the Fans Low Speed ON and OFF. Does the test lamp turn ON and OFF with each command?Go to Step 12Go to Step 9
6Turn OFF the ignition. Disconnect the FAN CONT #3 relay. Turn ON the ignition, with the engine OFF. Probe the battery positive voltage circuit of the FAN CONT #3 relay with a test lamp that is connected to a good ground. Does the test lamp illuminate?Go to Step 7Go to Step 16
7Connect a test lamp between the control circuit of the FAN CONT #3 relay and the battery positive voltage circuit of the FAN CONT #3 relay. With a scan tool, command the Fans High Speed ON and OFF. Does the test lamp turn ON and OFF with each command?Go to Step 14Go to Step 8
8Turn Off the ignition. Disconnect the FAN CONT #2 relay. Turn ON the ignition with the engine OFF. Connect a test lamp between the control circuit of the FAN CONT #2 relay and the battery positive voltage circuit of the FAN CONT #2 relay. With a scan tool, command the Fans High Speed ON and OFF. Does the test lamp turn ON and OFF with each command?Go to Step 13Go to Step 9
9Does the test lamp remain illuminated with each command?Go to Step 11Go to Step 10
10Test the control circuit of the appropriate relay for a short to voltage or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 22Go to Step 15
11Test the control circuit of the appropriate relay for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 22Go to Step 15
12Inspect for poor connections at the FAN CONT #1 relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 22Go to Step 18
13Inspect for poor connections at the FAN CONT #2 relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 22Go to Step 19
14Inspect for poor connections at the FAN CONT #3 relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 22Go to Step 20
15Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 22Go to Step 21
16Repair the battery positive voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 22
17Repair the cooling fan motor supply voltage circuit for a short to ground. Refer to Wiring Repairs in Wiring Systems.Go to Step 22
18Replace the FAN CONT #1 relay. Did you complete the replacement?Go to Step 22
19Replace the FAN CONT #2 relay. Did you complete the replacement?Go to Step 22
20Replace the FAN CONT #3 relay. Did you complete the replacement?Go to Step 22
21IMPORTANT: Perform the programming procedure for the PCM. Replace the PCM. Refer to POWERTRAIN CONTROL MODULE .Did you complete the replacement?Go to Step 22
22Use the scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset?Go to Step 2System OK
IMPORTANT
Perform the programming procedure for the PCM.

DTC P0480 Or P0481

Symptoms - Engine Cooling

IMPORTANTReview the system operation in order to familiarize yourself with the system functions. Refer to Cooling System Description and Operation .

Visual/Physical Inspection

  1. Inspect for aftermarket devices which could affect the operation of the Cooling System. Refer to «Checking Aftermarket Accessories»(/chevrolet/monte-carlo/vi-1999-2007/remont/body-electrical/#wiring-systems-introduction__checking-aftermarket-accessories) in Wiring Systems.
  2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
  3. Inspect the surge tank reservoir for the proper coolant level.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

  1. «Engine Coolant Temperature Indicator Always On»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__engine-coolant-temperature-indicator-always-on)
  2. «Cooling Fan Always On»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__cooling-fan-always-on)
  3. «Cooling Fan Inoperative»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__cooling-fan-inoperative)
  4. «Coolant Heater Inoperative»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__coolant-heater-inoperative)
  5. «Engine Overheating»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__engine-overheating)
  6. «Loss of Coolant»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant)
  7. «Thermostat Diagnosis (Overheating)»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__thermostat-diagnosis-overheating) or «Thermostat Diagnosis (Slow to heat)»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__thermostat-diagnosis-slow-to-heat)
  8. «Engine Fails To Reach Normal Operating Temperature»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__engine-fails-to-reach-normal-operating)

Engine Coolant Temperature Indicator Always On

StepActionYesNo
Connector End View Reference: Cooling System Connector End Views DEFINITION: The engine coolant temperature indicator is always ON and no powertrain DTCs have been set.
1Did you perform the Engine Cooling Diagnostic System Check?Go to Step 2Go to Diagnostic System Check - Engine Cooling
2Start the engine. Does the Engine Coolant Temperature indicator illuminate?Go to Step 3Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
3Connect the diagnostic scan tool. With the scan tool, observe the engine coolant temperature (ECT) sensor parameter in the Powertrain Control Module data list. Does the scan tool indicate that the coolant temperature is within the temperature range shown on the temperature gauge?Go to Engine OverheatingGo to Step 4
4Replace the instrument panel cluster. Refer to Instrument Panel Cluster (IPC) Replacement in Instrument Panel Gages and Console. Is the replacement complete?Go to Step 5
5Operate the system in order to verify the repair. Did you correct the condition?System OKGo to Step 3

Engine Coolant Temperature Indicator Always On

Cooling Fan Always On

StepActionYesNo
Schematic Reference: Engine Cooling Schematics Connector End View Reference: Cooling System Connector End Views DEFINITION: One or both engine cooling fan motors run continuously in high or low speed modes.
1Did you perform the Engine Cooling Diagnostic System Check?Go to Step 2Go To Diagnostic System Check - Engine Cooling
2Turn ON the ignition, with the engine OFF. Are one or both cooling fans ON?Go to Step 3Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
3Are both cooling fans running continuously?Go to Step 5Go to Step 4
4Remove the FAN CONT #2 relay. Did the left cooling fan turn OFF?Go to Step 8Go to Step 6
5Remove the FAN CONT #1 relay. Did the cooling fans turn OFF?Go to Step 10Go to Step 7
6Remove the FAN CONT #3 relay. Did the left cooling fan turn OFF?Go to Step 11Go to Step 9
7Repair the short to voltage in the right cooling fan motor supply voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 14
8Repair the short to voltage in the right cooling fan low reference circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 14
9Repair the short to voltage in the left cooling fan motor supply voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 14
10Inspect for poor connections at the FAN CONT #1 relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Repairs. Did you find and correct the condition?Go to Step 14Go to Step 12
11Inspect for poor connections at the FAN CONT #3 relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Repairs. Did you find and correct the condition?Go to Step 14Go to Step 13
12Replace the FAN CONT #1 relay. Did you complete the replacement?Go to Step 14
13Replace the FAN CONT #3 relay. Did you complete the replacement?Go to Step 14
14Operate the system in order to verify the repair. Did you correct the condition?System OKGo to Step 2

Cooling Fan Always On

Cooling Fan Inoperative

StepActionYesNo
Schematic Reference: Engine Cooling Schematics Connector End View Reference: Cooling System Connector End Views DEFINITION: One or both engine cooling fan motors do not operate properly in high or low speed modes.
1Did you perform the Engine Cooling Diagnostic System Check?Go to Step 2Go to Diagnostic System Check - Engine Cooling
2Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the Fans Low Speed ON and OFF. Do the low speed engine cooling fans turn ON and OFF with each command?Go to Step 3Go to Step 4
3IMPORTANT: A 3-second delay occurs before the PCM changes the cooling fan speed. With a scan tool, command the Fans High Speed ON and OFF.Do the high speed engine cooling fans turn ON and OFF with each command?Go to Testing for Intermittent Conditions and Poor Connections in Wiring SystemsGo to Step 12
4IMPORTANT: Do NOT remove the 20-A fused jumper wire connected during this step. Use a second 20-A fused jumper wire while performing the following steps. Remove the FAN CONT #1 relay. Connect a 20-A fused jumper between the battery positive switch side voltage circuit and the cooling fan motor supply voltage circuit of the FAN CONT #1 relay. Do both cooling fans operate in low speed?Go to Step 22Go to Step 5
5Disconnect the FAN CONT #2 relay Connect the second 20-A fused jumper between the cooling fan low reference circuit and the cooling fan motor supply voltage circuit of the FAN CONT #2 relay. Do both cooling fans operate in low speed?Go to Step 23Go to Step 6
6Connect the second 20-ampere fused jumper between the battery positive voltage circuit and the cooling fan motor supply voltage circuit of the FAN CONT #2 relay. Does the left cooling fan operate in high speed?Go to Step 9Go to Step 7
7Install the FAN CONT #2 relay. Disconnect the left cooling fan electrical connector. Connect the second 20-ampere fused jumper wire from the cooling fan motor supply voltage circuit to the ground circuit of the left cooling fan electrical connector. Does the right cooling fan operate in high speed?Go to Step 25Go to Step 8
8Connect the second 20-ampere fused jumper wire from the cooling fan motor supply voltage circuit of the left cooling fan electrical connector to a good ground. Does the right cooling fan operate in high speed?Go to Step 29Go to Step 30
9Install the FAN CONT #2 relay. Disconnect the right cooling fan electrical connector. Connect the second 20-ampere fused jumper wire from the cooling fan motor supply voltage circuit to the cooling fan low reference circuit of the right cooling fan electrical connector. Does the left cooling fan operate in high speed?Go to Step 26Go to Step 10
10Connect the second 20-ampere fused jumper wire from the coil side battery positive voltage circuit to the cooling fan low reference circuit of the of the right cooling fan electrical connector. Does the left cooling fan operate in high speed?Go to Step 11Go to Step 31
11Probe the battery positive voltage circuit on the switch side of the FAN CONT #1 relay with a test lamp that is connected to a good ground. Does the test lamp illuminate?Go to Step 27Go to Step 32
12Is the left cooling fan operating properly in high speed?Go to Step 19Go to Step 13
13Turn off the ignition. Disconnect the FAN CONT #3 relay. Turn ON the ignition, with the engine OFF. Connect a test lamp between the high speed cooling fan relay control circuit and the battery positive voltage circuit on the coil side of the FAN CONT #3 relay. With a scan tool command the High Speed Fans ON and OFF. Does the test lamp turn ON and OFF with each command?Go to Step 15Go to Step 14
14Probe the battery positive voltage circuit on the coil side of the FAN CONT #3 relay with a test lamp that is connected to a good ground. Does the test lamp illuminate?Go to Step 34Go to Step 33
15Install a 20 amp fused jumper between the battery positive voltage circuit on the switch side of the FAN CONT #3 relay and the cooling fan motor supply voltage circuit. Does the left cooling fan operate in high speed?Go to Step 24Go to Step 16
16Probe the battery positive voltage circuit on the switch side of the FAN CONT #3 relay with a test lamp connected to a good ground. Does the test lamp illuminate?Go to Step 17Go to Step 33
17With the 20 amp fused jumper still installed. Disconnect the left cooling fan electrical connector. Connect a test lamp from the cooling fan motor supply voltage circuit to the ground circuit of the left cooling fan electrical connector. Does the test lamp illuminate?Go to Step 25Go to Step 18
18Probe the cooling fan motor supply voltage circuit of the left cooling fan electrical connector with a test lamp that is connected to a good ground. Does the test lamp illuminate?Go to Step 29Go to Step 30
19Turn OFF the ignition. Disconnect the FAN CONT #2 relay Turn ON the ignition, with the engine OFF. Connect a 20-A fused jumper between the cooling fan low reference circuit and the ground circuit of the FAN CONT #2 relay. With a scan tool command the Fans High Speed ON and OFF. Does the right cooling fan operate in high speed?Go to Step 20Go to Step 28
20Connect a test lamp between the high speed cooling fan relay control circuit of the FAN CONT #2 relay and the battery positive voltage circuit of the FAN CONT #2 relay. With a scan tool command the Fans High Speed ON and OFF. Does the test lamp turn ON and OFF with each command?Go to Step 23Go to Step 21
21Probe the battery positive voltage circuit of the FAN CONT #2 relay with a test lamp that is connected to a good ground. Does the test lamp illuminate?Go to Step 34Go to Step 33
22Inspect for poor connections at the FAN CONT #1 relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 40Go to Step 35
23Inspect for poor connections at the FAN CONT #2 relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 40Go to Step 36
24Inspect for poor connections at the FAN CONT #3 relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 40Go to Step 37
25Inspect for poor connections at the harness connector of the left cooling fan. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 40Go to Step 38
26Inspect for poor connections at the harness connector of the right cooling fan. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 40Go to Step 39
27Repair the right cooling fan motor supply voltage circuit for an open. Refer to Wiring Repairs in Wiring Systems. Is the repair complete?Go to Step 40
28Repair the right cooling fan ground circuit for an open. Refer to Wiring Repairs in Wiring Systems. Is the repair complete?Go to Step 40
29Repair the left cooling fan ground circuit for an open. Refer to Wiring Repairs in Wiring Systems. Is the repair complete?Go to Step 40
30Repair the left cooling fan motor supply voltage circuit for an open. Refer to Wiring Repairs in Wiring Systems. Is the repair complete?Go to Step 40
31Repair the right cooling fan low reference circuit for a short to ground or an open. Refer to Wiring Repairs in Wiring Systems. Is the repair complete?Go to Step 40
32Repair the FAN CONT #1 relay battery positive voltage circuit for an open. Is the repair complete?Go to Step 40
33Repair the battery positive voltage circuit for the FAN CONT #2 and #3 relay for an open. Is the repair complete?Go to Step 40
34Repair the high speed cooling fan relay control circuit for an open. Is the repair complete?Go to Step 40
35Replace the FAN CONT #1 relay. Is the repair complete?Go to Step 40
36Replace the FAN CONT #2 relay. Is the repair complete?Go to Step 40
37Replace the FAN CONT #3 relay. Is the repair complete?Go to Step 40
38Replace the left cooling fan. Refer to Cooling Fan and Shroud Replacement . Is the repair complete?Go to Step 40
39Replace the right cooling fan. Refer to Cooling Fan and Shroud Replacement . Is the repair complete?Go to Step 40
40Operate the system in order to verify the repair. Did you correct the condition?System OKGo to Step 3
IMPORTANT
A 3-second delay occurs before the PCM changes the cooling fan speed.
IMPORTANT
Do NOT remove the 20-A fused jumper wire connected during this step. Use a second 20-A fused jumper wire while performing the following steps.

Cooling Fan Inoperative

Engine Overheating

StepActionValuesYesNo
DEFINITION: The engine temperature lamp comes on and stays on, the temperature gauge shows hot or coolant overflows from the coolant recovery reservoir onto the ground while the engine is running.
1Check for a loss of coolant. Has there been a loss of coolant?Go to Step 2Go to Step 3
2Refer to Loss of Coolant . Does the engine still overheat?Go to Step 3System OK
3Use J 24460-01 Cooling System Pressure Tester to test for a loss of system pressure. See Special Tools . Did you discover a loss of system pressure?Go to Step 4Go to Step 5
4Correct the system pressure. Does the engine still overheat?Go to Step 5System OK
5Use J 23688 Coolant Battery Fluid Tester to inspect for low coolant protection. See Special Tools . Is the low coolant protection at or above the specified value?37°C (4°F)Go to Step 7Go to Step 6
6Correct as necessary. Does the engine still overheat?Go to Step 7System OK
7Check for an inoperative cooling fan. Refer to Cooling System Description and Operation . Are any of the cooling fans inoperative?Go to Step 8Go to Step 9
8Repair or replace the electric cooling fans as necessary. Refer to Cooling Fan and Shroud Replacement . Does the engine still overheat?Go to Step 9System OK
9Inspect the drive belt tensioner for proper operation. Is the tensioner working properly and is the tension correct?Go to Step 11Go to Step 10
10Replace the tensioner as necessary. Refer to one of the following procedures: Drive Belt Tensioner Replacement in Engine Mechanical - 3.4L Drive Belt Tensioner Replacement in Engine Mechanical - 3.8L Does the engine still overheat?Go to Step 11System OK
11Inspect the radiator fins for an obstruction. Are any of radiator fins obstructed?Go to Step 12Go to Step 13
12Remove or relocate any add-on parts that block air to the radiator. Remove any debris from the radiator fins. Does the engine still overheat?Go to Step 13System OK
13Inspect the cooling system passages for rust or scale. Are any of the cooling system passages blocked by rust or scale?Go to Step 14Go to Step 15
14Drain the cooling system. Refer to Draining and Filling Cooling System . Flush the cooling system. Refer to Flushing . Repair as necessary.Does the engine still overheat?Go to Step 15System OK
15Inspect for a pinched or a kinked hose to the coolant recovery reservoir. Is the reservoir hose pinched or kinked?Go to Step 16Go to Step 17
16Replace or reroute the hose as necessary. Refer to Coolant Recovery Reservoir Replacement . Does the engine still overheat?Go to Step 17System OK
17Inspect for a loose, damaged or a missing deflector. Did you find any loose, damaged or missing deflectors?Go to Step 18Go to Step 19
18Replace the deflectors. Refer to Radiator Air Baffle and Deflector Replacement - Lower , to Radiator Air Baffle and Deflector Replacement - Side , or to Radiator Air Baffle and Deflector Replacement - Upper . Does the engine still overheat?Go to Step 19System OK
19Inspect the position of the thermostat. Refer to Thermostat Diagnosis (Overheating) or Thermostat Diagnosis (Slow to heat) . Is the thermostat stuck in the closed position?Go to Step 20Go to Step 21
20Replace the thermostat. Refer to Thermostat Replacement (3.4L) or Thermostat Replacement (3.8L) . Does the engine still overheat?Go to Step 21System OK
21Test for a faulty water pump. Is the water pump faulty?Go to Step 22Go to Step 23
22Replace the water pump. Refer to Water Pump Replacement (3.4L) or Water Pump Replacement (3.8L) . Does the engine still overheat?Go to Step 23System OK
23Inspect for an incorrect radiator. Is the radiator incorrect?Go to Step 24
24Install the correct radiator. Refer to Radiator Replacement . Does the engine still overheat?System OK

Engine Overheating

Loss of Coolant

StepActionYesNo
1Were you sent here from SYMPTOMS or another diagnostic table?Go to Step 2Go to Symptoms - Engine Cooling in Engine Cooling
2Repair any present DTCs. Refer to Diagnostic System Check - Engine Cooling . Is the action complete?Go to Step 3
3Inspect the coolant level. Is the coolant at the proper level?Go to Step 6Go to Step 4
4Fill the cooling system to the proper level. Refer to Draining and Filling Cooling System . Is the action complete?Go to Step 5
5If 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 6Go to Step 26
6Engine overheating can cause a loss of coolant. Is the engine overheating?Go to Step 27Go to Step 7
7Extended operation with a low coolant level can cause engine internal component failure. Is the engine knocking?Go to Step 29Go to Step 8
8Idle 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 9Go to Step 10
9Coolant 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 28Go to Step 10
10With the engine idling, inspect the coolant recovery system. Does the coolant recovery system discharge coolant while the engine is idling?Go to Step 15Go to Step 11
11Visually inspect the hoses, pipes and hose clamps at the following locations: Coolant bypass Coolant reservoir Heater core Radiator Are any of the hoses, clamps or pipes leaking?Go to Step 20Go to Step 12
12Visually 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 20Go to Step 13
13Pressure 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 20Go to Step 14
14Pressure test the coolant pressure cap. Refer to Pressure Cap Testing . Does the coolant pressure cap hold pressure?Go to Step 16Go to Step 21
15Pressure test the coolant pressure cap. Refer to Pressure Cap Testing . Does the coolant pressure cap hold pressure?Go to Step 30Go to Step 21
16Inspect for the following conditions: A coolant smell inside of the vehicle. Coolant in the HVAC module drain tube. Coolant on the vehicles floor covering near the HVAC module. Is coolant present?Go to Step 22Go to Step 17
17Inspect the underside of the engine oil fill cap for a gray/white milky substance. Is there a milky substance on the oil fill cap?Go to Step 18Go to Step 19
18Inspect the engine oil fluid level indicator for a gray/white milky substance. Is there a milky substance on the engine fluid level indicator?Go to Step 28Go to Step 19
19Inspect the automatic transmission oil fluid level indicator, for a gray/white milky substance. Is there a milky substance on the automatic transmission fluid level indicator?Go to Step 23Go to Step 31
20Repair or replace the leaking component. Refer to the appropriate repair. Is the repair complete?Go to Step 31
21Replace the coolant pressure cap. Is the repair complete?Go to Step 31
22Replace the heater core. Refer to Heater Core Replacement in Heating Ventilation and Air Conditioning. Is the repair complete?Go to Step 31
23Remove 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 24Go to Step 25
24Replace the radiator. Refer to Radiator Replacement . Service the automatic transmission. Is the repair complete?Go to Step 31
25Install the cooler lines to the radiator. Is the repair complete?Go to Step 31
26Repair the engine no crank condition. Refer to Engine Will Not Crank - Crankshaft Will Not Rotate in Engine Mechanical 3.4L. or Engine Will Not Crank - Crankshaft Will Not Rotate in Engine Mechanical 3.8L. Is the repair complete?Go to Step 31
27Repair the engine overheating condition. Refer to Engine Overheating . Is the repair complete?Go to Step 31
28Repair the engine internal coolant leak. Refer to Coolant in Combustion Chamber in Engine Mechanical 3.4L or Coolant in Engine Oil in Engine Mechanical 3.4L or Coolant in Combustion Chamber in Engine Mechanical 3.8L or Coolant in Engine Oil in Engine Mechanical 3.8L Is the repair complete?Go to Step 31
29Repair the engine knock. Refer to Lower Engine Noise, Regardless of Engine Speed in Engine Mechanical 3.4L or Lower Engine Noise, Regardless of Engine Speed in Engine Mechanical 3.8L. Is the repair complete?Go to Step 31
30Repair the combustion pressure in the cooling system problem. Refer to Cylinder Leakage Test in Engine Mechanical 3.4L or Cylinder Leakage Test in Engine Mechanical 3.8L. Is the repair complete?Go to Step 31
31Operate the system in order to verify the repair. Did you find and correct the condition?System OKGo to Step 2

Loss Of Coolant

Thermostat Diagnosis (Overheating)

StepActionYesNo
IMPORTANT: The J 24731 Tempil Stick is a pencil-like device that has a wax material containing certain chemicals which melt at a given temperature. See Special Tools . Use the temperature sticks to determine a thermostats operating temperature by rubbing 87°C (188°F) and 97°C (206°F) sticks on the coolant outlet. The marks made by the sticks should melt when coolant temperatures reach 87°C (188°F) and 97°C (206°F), respectively. These temperatures are the normal operating range of the thermostat.
1Remove the radiator cap. Refer to Draining and Filling Cooling System . Rub a 97°C (206°F) J 24731 on the coolant outlet. See Special Tools . Warm up the engine at fast idle. Check for coolant flow before the mark begins to melt. Is there coolant flow before the mark melts?Go to Step 2Go to Step 3
2The problem is caused from something other than the thermostat. Refer to Engine Overheating . Does the engine still overheat?System OK
3Replace the thermostat. Refer to Thermostat Replacement (3.4L) or Thermostat Replacement (3.8L) . Check the system Is the engine still overheating?System OK
IMPORTANT
The J 24731 Tempil Stick is a pencil-like device that has a wax material containing certain chemicals which melt at a given temperature. See Special Tools . Use the temperature sticks to determine a thermostats operating temperature by rubbing 87°C (188°F) and 97°C (206°F) sticks on the coolant outlet. The marks made by the sticks should melt when coolant temperatures reach 87°C (188°F) and 97°C (206°F), respectively. These temperatures are the normal operating range of the thermostat.

Thermostat Diagnosis (Overheating)

Thermostat Diagnosis (Slow to heat)

StepActionYesNo
IMPORTANT: The J 24731 Tempil Stick is a pencil-like device that has a wax material containing certain chemicals which melt at a given temperature. See Special Tools . Use the temperature sticks to determine a thermostats operating temperature by rubbing 87°C (188°F) and 97°C (206°F) sticks on the coolant outlet. The marks made by the sticks should melt when coolant temperatures reach 87°C (188°F) and 97°C (206°F), respectively. These temperatures are the normal operating range of the thermostat.
1Remove the radiator cap. Refer to Draining and Filling Cooling System . Rub a 87°C (188°F) J 24731 on the coolant outlet. See Special Tools . Warm up the engine at fast idle. Check for coolant flow before the mark begins to melt. Is there coolant flow before the mark melts?Go to Step 3Go to Step 2
2The problem is caused from something other than the thermostat. Refer to Engine Fails To Reach Normal Operating Temperature . Does the engine warm up properly?System OK
3Replace the thermostat. Refer to Thermostat Replacement (3.4L) or Thermostat Replacement (3.8L) . Check the system. Does the engine fail to reach normal operating temperature?System OK
IMPORTANT
The J 24731 Tempil Stick is a pencil-like device that has a wax material containing certain chemicals which melt at a given temperature. See Special Tools . Use the temperature sticks to determine a thermostats operating temperature by rubbing 87°C (188°F) and 97°C (206°F) sticks on the coolant outlet. The marks made by the sticks should melt when coolant temperatures reach 87°C (188°F) and 97°C (206°F), respectively. These temperatures are the normal operating range of the thermostat.

Thermostat Diagnosis (Slow To Heat)

Coolant Heater Inoperative

StepActionYesNo
1Did you perform the necessary inspections?Go to Step 2Go to Symptoms - Engine Cooling
2Test the engine coolant heater power supply cord for an open or short to ground. Refer to Circuit Testing in Wiring Systems. Did you find a condition?Go to Step 4Go to Step 3
3Inspect for poor connections at the harness connector of the engine coolant heater. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 6Go to Step 5
4Replace the engine coolant heater power supply cord. Refer to Coolant Heater Cord Replacement (3.4L) or Coolant Heater Cord Replacement (3.8L) . Did you complete the repair?Go to Step 6
5Replace the engine coolant heater. Refer to Coolant Heater Replacement (3.4L) or Coolant Heater Replacement (3.8L) . Did you complete the repair?Go to Step 6
6Operate the system in order to verify the repair. Did you correct the condition?System OKGo to Step 2

Coolant Heater Inoperative

Engine Fails To Reach Normal Operating Temperature

StepActionYesNo
1Check the coolant level in the coolant recovery reservoir. Is the coolant at the proper level?Go to Step 3Go to Step 2
2Add coolant to the coolant recovery reservoir as necessary. Does the engine still fail to reach normal operating temperature?Go to Step 3System OK
3Check for a blockage in the coolant passages. Are there any blockages in the coolant passages?Go to Step 4Go to Step 5
4Flush the cooling system or flow check the radiator. Refer to Flushing . Does the engine still fail to reach normal operating temperature?Go to Step 5System OK
5Check to see if the incorrect type of thermostat was installed, or if the thermostat is stuck (or sticks) in the open position. Refer to Thermostat Diagnosis (Overheating) or Thermostat Diagnosis (Slow to heat) . Was the incorrect thermostat installed, or is the thermostat stuck (or does the thermostat stick) in the open position?Go to Step 6
6Replace the thermostat. Refer to Thermostat Replacement (3.4L) or Thermostat Replacement (3.8L) . Does the engine still reach normal operating temperature?System OK

Engine Fails To Reach Normal Operating Temperature

Pressure Cap Testing

Tools Required

J 24460-01 Cooling System Pressure Tester. See Special Tools .

  1. Remove the pressure cap.
  2. Wash the pressure cap sealing surface with water.
  3. Use the J 24460-01 in order to test the pressure cap. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  4. Test the pressure cap for the following conditions: Pressure release when the J 24460-01 exceeds the pressure rating of the pressure cap. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) . Maintain the rated pressure for at least 10 seconds. Note the rate of pressure loss.
  5. Replace the pressure cap under the following conditions: The pressure cap does not release pressure which exceeds the rated pressure of the cap. The pressure cap does not hold the rated pressure.

Cooling System Leak Testing

Tools Required

J 24460-01 Cooling System Pressure Tester. See Special Tools .

  1. Remove the pressure cap.
  2. Test the operation of the pressure cap. Refer to «Pressure Cap Testing»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__pressure-cap-testing) .
  3. Wash the pressure cap mating surface with water.
  4. Use the J 24460-01 in order to apply pressure to the cooling system. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) . Do not exceed the pressure cap rating.
  5. The cooling system should hold the rated pressure for at least 2 minutes. Observe the gage for any pressure loss.
  6. Repair any leaks as required.

Draining Procedure

CAUTIONWith a pressurized cooling system, the coolant temperature in the radiator can be considerably higher than the boiling point of the solution at atmospheric pressure. Removal of the surge tank cap, while the cooling system is hot and under high pressure, causes the solution to boil instantaneously with explosive force. This will cause the solution to spew out over the engine, the fenders, and the person removing the cap. Serious bodily injury may result.
  1. Park the vehicle on a level surface.
  2. Remove the coolant pressure cap.
  3. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/monte-carlo/vi-1999-2007/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
  4. Place a drain pan under the drain cock.
  5. Open the radiator drain cock.
  6. Drain the cooling system.
  7. If a complete engine block drain is required, remove the engine block drain plug.
  8. Inspect the coolant.
  9. Follow the appropriate procedure based on the condition of the coolant. Normal in appearance - follow the filling procedure. Discolored - follow the flush procedure. Refer to «Flushing»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__flushing) .

Filling Procedure

Tools Required

J 23688 Coolant and Battery Fluid Tester. See Special Tools .

  1. Close the radiator drain cock. Tighten: Tighten the radiator drain cock to 2 N.m (18 lb in).
  2. If the engine block drain plug was removed, perform the following: Apply pipe sealer to the drain plug. Install the drain plug. Tighten: Tighten the drain plug to 22 N.m (16 lb ft).
  3. Lower the vehicle.
  4. Open the cooling system bleeder screws.
  5. Slowly fill the cooling system with a 50/50 coolant mixture.
  6. Close the cooling system bleeder screws.
  7. Install the coolant pressure cap.
  8. Start the engine.
  9. Run the engine at 2,000 - 2,500 RPM until the engine reaches normal operating temperature.
  10. Allow the engine to idle for 3 minutes.
  11. Shut the engine off.
  12. Allow the engine to cool.
  13. Top off the coolant as necessary.
  14. Inspect the concentration of the engine coolant. Using the J 23688 . See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  15. Rinse away any excess coolant from the engine and the engine compartment.
  16. Inspect the cooling system for leaks.

Flushing

IMPORTANTDo not use a chemical flush.

Store used coolant in a properly labeled container. Do not pour used coolant down a drain. Ethylene glycol antifreeze is a very toxic chemical. Do not dispose of coolant into the sewer system or ground water. This is illegal and ecologically unsound.

Various methods and equipment can be used to flush the cooling system. If special equipment is used, such as a back flusher, follow the manufacturer's instruction.

When the cooling system becomes contaminated, the cooling system should be flushed thoroughly to remove the contaminants before the engine is seriously damaged.

  1. Drain the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  2. Remove the coolant recovery reservoir. Refer to «Coolant Recovery Reservoir Replacement»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  3. Clean and flush the coolant recovery reservoir with clean, drinkable water.
  4. Install the coolant recovery reservoir. Refer to «Coolant Recovery Reservoir Replacement»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  5. Follow the drain and fill procedure using only clean, drinkable water. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  6. Run the engine for 20 minutes.
  7. Stop the engine.
  8. Drain the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  9. Repeat the procedure if necessary, until the fluid is nearly colorless.
  10. Fill the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .

Radiator Cleaning

CAUTIONNEVER 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.

  1. Some conditions may require the use of warm water and a mild detergent.
  2. Clean the A/C condenser fins.
  3. Clean between the A/C condenser and radiator.
  4. Clean the radiator cooling fins.
  5. Straighten any damaged cooling fins.

Removal Procedure

  1. Remove the cross vehicle brace. Refer to «Brace Replacement - Cross Vehicle»(/chevrolet/monte-carlo/vi-1999-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
  2. Reposition the reservoir hose clamp (1).
  3. Remove the reservoir hose from the radiator overflow neck.
  4. Remove the coolant recovery reservoir nuts (2) from the shock tower studs.
  5. Remove the coolant recovery reservoir (3) from the lower retainer and the shock tower studs.
  6. Drain the coolant from the recovery reservoir in to a clean container.

Installation Procedure

  1. Install the coolant recovery reservoir (3) onto the lower retainer and the shock tower studs.
  2. Install the coolant recovery reservoir nuts (2) to the shock tower studs. Tighten: Tighten the nuts to 3.3 N.m (29 lb in).
  3. Lubricate the reservoir hose with clean water. Route the hose to the radiator overflow neck fitting.
  4. Install the coolant reservoir hose (1) to the overflow neck fitting.
  5. Install the reservoir hose and clamp (1), with the clamp tabs at the 11 o'clock position, to the radiator overflow fitting on the radiator filler neck. The hose end must be flush against the radiator filler neck. Seat the clamp squarely between the radiator filler neck and the flared end of the fitting.
  6. Install the cross vehicle brace. Refer to «Brace Replacement - Cross Vehicle»(/chevrolet/monte-carlo/vi-1999-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
  7. Fill the coolant recovery reservoir to the proper level.

Tools Required

J 38185 Hose Clamp Pliers. See Special Tools .

  1. Partially drain the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  2. Remove the left diagonal brace. Refer to «Brace Replacement - Front Fender Upper Diagonal»(/chevrolet/monte-carlo/vi-1999-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
  3. Use the J 38185 in order to reposition the hose clamp from the water outlet housing. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  4. Remove the radiator inlet hose (1) from the water outlet housing.
  5. Use the J 38185 in order to reposition the hose clamp from the radiator. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  6. Remove the radiator inlet hose from the radiator and the vehicle.
  1. Align the marks on the hose. Install the radiator inlet hose to the radiator.
  2. Use the J 38185 in order to reposition and install the hose clamp to the radiator. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  3. Install the radiator inlet hose (1) to the water outlet housing.
  4. Use the J 38185 in order to reposition and install the inlet hose to the water outlet housing. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  5. Install the left diagonal brace. Refer to «Brace Replacement - Front Fender Upper Diagonal»(/chevrolet/monte-carlo/vi-1999-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
  6. Fill the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .

J 38185 Hose Clamp Pliers. See Special Tools .

  1. Partially drain the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  2. Remove the left diagonal brace. Refer to «Brace Replacement - Front Fender Upper Diagonal»(/chevrolet/monte-carlo/vi-1999-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
  3. Use the J 38185 in order to reposition the hose clamp from the radiator. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  4. Remove the radiator inlet hose from the radiator.
  5. Use the J 38185 in order to reposition the hose clamp from the water outlet housing. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  6. Remove the radiator inlet hose from the water outlet housing and the vehicle.
  1. Align the marks on the hose. Install the radiator inlet hose to the water outlet housing.
  2. Use the J 38185 in order to reposition and install the hose clamp to the water outlet housing. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  3. Install the radiator inlet hose to the radiator.
  4. Use the J 38185 in order to reposition and install the hose clamp to the radiator. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  5. Install the left diagonal brace. Refer to «Brace Replacement - Front Fender Upper Diagonal»(/chevrolet/monte-carlo/vi-1999-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
  6. Fill the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .

J 38185 Hose Clamp Pliers. See Special Tools .

  1. Drain the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  2. Use J 38185 in order to reposition the hose clamp from the water pump housing. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  3. Remove the radiator outlet hose (2) from the water pump housing.
  4. Remove the lower radiator air deflector. Refer to «Radiator Air Baffle and Deflector Replacement - Lower»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  5. Use the J 38185 in order to reposition the hose clamp from the radiator. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  6. Remove the radiator outlet hose from the radiator.
  1. Align the marks on the hose. Install the outlet hose to the radiator.
  2. Use J 38185 in order to reposition the hose clamp to the radiator. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  3. Install the radiator lower air deflector. Refer to «Radiator Air Baffle and Deflector Replacement - Lower»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  4. Install the radiator outlet hose to the water pump housing (2).
  5. Use J 38185 in order to reposition the hose clamp to the water pump housing. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  6. Fill the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .

J 38185 Hose Clamp Pliers. See Special Tools .

  1. Drain the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  2. Remove the lower radiator air deflector. Refer to «Radiator Air Baffle and Deflector Replacement - Lower»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  3. Use the J 38185 in order to reposition the hose clamp from the radiator. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  4. Remove the radiator outlet hose (3) from the radiator (2).
  5. Lower the vehicle.
  6. Use J 38185 in order to reposition the hose clamp from the water pump housing. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  7. Remove the radiator outlet hose from the water pump housing.
  1. Align the marks on the hose. Install the radiator outlet hose to the water pump housing.
  2. Use J 38185 in order to reposition the hose clamp to the water pump housing. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  3. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/monte-carlo/vi-1999-2007/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
  4. Install the radiator outlet hose (3) to the radiator (2).
  5. Use J 38185 in order to reposition the hose clamp to the radiator. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  6. Install the lower radiator air deflector. Refer to «Radiator Air Baffle and Deflector Replacement - Lower»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  7. Fill the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  1. Remove the air cleaner intake duct.
  2. Partially drain the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  3. Remove the throttle body inlet hose clamp and the hose (3) from the coolant pipe.
  4. Remove the throttle body inlet hose clamp and the hose (3) from the throttle body and the vehicle.
  1. Install the throttle body inlet hose (3) and the hose clamp to the throttle body.
  2. Install the throttle body inlet hose (3) and the hose clamp to the coolant pipe.
  3. Install the air cleaner intake duct.
  4. Fill the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  1. Remove the air cleaner intake duct.
  2. Partially drain the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  3. Remove the throttle body outlet hose clamp and the hose (4) from the coolant pipe.
  4. Remove the throttle body outlet hose clamp and the hose (4) from the throttle body and the vehicle.
  1. Install the throttle body outlet hose (4) and the hose clamp to the throttle body.
  2. Install the throttle body outlet hose (4) and the hose clamp to the coolant pipe.
  3. Install the air cleaner intake duct.
  4. Fill the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .

J 42971 Quick Connect Release Tool. See Special Tools .

  1. Lubricate and carefully insert the appropriate end of J 42971 behind the release collar. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  2. Pull the hose assembly (1) out of the mating connector (3).
  3. Inspect the male fitting (1), the female fitting (3), and the release collar (2) for the following conditions: Nicks Scratches Flat spots Damaged O-rings Damaged release collar
  4. If any of the above conditions exist replace the appropriate part.
  1. Align the male fitting (1) with the female fitting (3).
  2. Push the fittings together until a definite snap and a solid stop are felt.
  3. Add the proper amount of engine oil.
  1. Remove the engine oil cooler from the vehicle. Refer to «Engine Oil Cooler Replacement - Auxiliary»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  2. Remove the right engine splash shield. Refer to «Splash Shield Replacement - Engine - Right»(/chevrolet/monte-carlo/vi-1999-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
  3. Remove the engine oil cooler lines from the engine oil filter adapter. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  4. Remove the engine oil cooler line mounting bolt (1).
  5. Remove the engine oil cooler line mounting block (2).
  6. Cut and remove the tie strap that holds the engine oil cooler lines to the frame.
  7. Remove the engine oil cooler lines from the vehicle.
  1. Install the engine oil cooler lines to the vehicle.
  2. Install the engine oil cooler to the vehicle. Refer to «Engine Oil Cooler Replacement - Auxiliary»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  3. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/monte-carlo/vi-1999-2007/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
  4. Install the engine oil cooler lines to the engine oil filter adapter. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  5. Install the engine oil cooler line mounting block (2) to the engine oil cooler lines.
  6. Install the bolt (1) through the engine oil cooler line mounting block. Tighten: Tighten the bolt to 3.4 N.m (30 lb in).
  7. Install a new tie strap around the engine oil cooler lines and frame.
  8. Install the right engine splash shield. Refer to «Splash Shield Replacement - Engine - Right»(/chevrolet/monte-carlo/vi-1999-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
  9. Add the proper amount of engine oil.
  1. Remove the radiator air baffle retainers.
  2. Tilt the rear of the air baffle upward slightly. Slide the air baffle rearward in order to disengage the upper and lower clips of the air baffle from the fascia support.
  3. Remove the radiator air baffle.
  4. Remove the upper bolt from the engine oil cooler.
  5. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/monte-carlo/vi-1999-2007/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
  6. Remove the 2 lower bolts from the engine oil cooler.
  7. Lower the engine oil cooler below the front bumper.
  8. Remove the engine oil cooler line block connector (3) from the engine oil cooler lines.
  9. Remove the oil cooler lines from the engine oil cooler. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  1. Install the engine oil cooler lines to the engine oil cooler. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  2. Install the engine oil cooler line block connector (3) to the engine oil cooler lines.
  3. Install the bolt through the engine oil cooler block connector and install nut. Tighten: Tighten the bolt to 3.4 N.m (30 lb in).
  4. Install the engine oil cooler to the vehicle.
  5. Install the 2 lower bolts to the engine oil cooler. Tighten: Tighten the bolts to 2 N.m (18 lb in).
  6. Install the upper bolt to the engine oil cooler. Tighten: Tighten the bolt to 2 N.m (18 lb in).
  7. Lower the vehicle.
  8. Position the radiator air baffle to the vehicle. Tilt the rear of the air baffle upward slightly. Position the upper clip of the air baffle to the lower edge of the front fascia support C-channel.
  9. Slide the baffle towards the front of the vehicle in order to completely engage the upper and lower clips of the baffle onto the fascia support.
  10. Align the tabs at the rear of the air baffle to the openings in the upper radiator support.
  11. Install the radiator air baffle retainers.
  12. Add the proper amount of engine oil.
CAUTIONAn electric fan under the hood can start up even when the engine is not running and can injure you. Keep hands, clothing and tools away from any underhood electric fan.
CAUTIONTo help avoid personal injury or damage to the vehicle, a bent, cracked, or damaged fan blade or housing should always be replaced.
CAUTIONBefore servicing any electrical component, the ignition key must be in the OFF or LOCK position and all electrical loads must be OFF, unless instructed otherwise in these procedures. If a tool or equipment could easily come in contact with a live exposed electrical terminal, also disconnect the negative battery cable. Failure to follow these precautions may cause personal injury and/or damage to the vehicle or its components.
  1. Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/monte-carlo/vi-1999-2007/remont/body-electrical/#battery-charging-system-starting-system) in Engine Electrical.
  2. Disconnect the cooling fans electrical connector.
  3. Partially drain the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  4. Remove the right and the left engine mount struts. Refer to the following procedures: «Engine Mount Strut Replacement - Right»(/chevrolet/monte-carlo/vi-1999-2007/remont/mechanical/#engine-mechanical-34l-v6-vin-e-la1) «Engine Mount Strut Replacement - Left»(/chevrolet/monte-carlo/vi-1999-2007/remont/mechanical/#engine-mechanical-34l-v6-vin-e-la1) in Engine Mechanical-3.4L «Engine Mount Strut Replacement - Right»(/chevrolet/monte-carlo/vi-1999-2007/remont/mechanical/#engine-mechanical-38l-l36) «Engine Mount Strut Replacement - Left»(/chevrolet/monte-carlo/vi-1999-2007/remont/mechanical/#engine-mechanical-38l-l36) in Engine Mechanical-3.8L
  5. Remove the left front fender upper diagonal brace. Refer to «Brace Replacement - Front Fender Upper Diagonal»(/chevrolet/monte-carlo/vi-1999-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
  6. Remove the radiator inlet hose from the radiator.
  7. Remove the air cleaner assembly.
  8. Remove the PCM harness from the fan shroud clip.
  9. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/monte-carlo/vi-1999-2007/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
  10. Remove the push pin retainer from the lower left side of the fan shroud.
  11. Remove the transmission oil cooler lines from the retainer clip at the bottom of the cooling fan shroud.
  12. Lower the vehicle.
  13. Remove the cooling fan shroud bolts.
  14. Disengage the cooling fan shroud clip from the top of the radiator.
  15. Remove the radiator upper support brackets and bolts that connect to the fan shroud.
  16. Remove the cooling fans electrical harness from the fan shroud clips.
  17. Remove the cooling fan shroud.
  1. Install the cooling fan shroud.
  2. Install the cooling fans electrical harness to the fan shroud clips.
  3. Connect the cooling fans electrical connector.
  4. Install the cooling fan shroud clip to the top of the radiator. Apply pressure in order to completely engage the clip onto the radiator.
  5. Install the cooling fan shroud bolts. Tighten: Tighten the bolts to 10 N.m (89 lb in).
  6. Install the radiator upper support brackets and bolts that connect to the fan shroud. Tighten: Tighten the bolts to 10 N.m (89 lb in).
  7. Install the air cleaner assembly.
  8. Install the PCM harness on to the fan shroud clip.
  9. Install the radiator inlet hose to the radiator.
  10. Install the left front fender upper diagonal brace. Refer to «Brace Replacement - Front Fender Upper Diagonal»(/chevrolet/monte-carlo/vi-1999-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
  11. Install the right and left engine mount struts. Refer to the following procedures: «Engine Mount Strut Replacement - Right»(/chevrolet/monte-carlo/vi-1999-2007/remont/mechanical/#engine-mechanical-34l-v6-vin-e-la1) «Engine Mount Strut Replacement - Left»(/chevrolet/monte-carlo/vi-1999-2007/remont/mechanical/#engine-mechanical-34l-v6-vin-e-la1) in Engine Mechanical-3.4L «Engine Mount Strut Replacement - Right»(/chevrolet/monte-carlo/vi-1999-2007/remont/mechanical/#engine-mechanical-38l-l36) «Engine Mount Strut Replacement - Left»(/chevrolet/monte-carlo/vi-1999-2007/remont/mechanical/#engine-mechanical-38l-l36) in Engine Mechanical-3.8L
  12. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/monte-carlo/vi-1999-2007/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
  13. Install the push pin retainer to the lower left side of the fan shroud.
  14. Install the transmission oil cooler lines to the retainer clip at the bottom of the cooling fan shroud.
  15. Lower the vehicle.
  16. Fill the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  17. Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/monte-carlo/vi-1999-2007/remont/body-electrical/#battery-charging-system-starting-system) in Engine Electrical.
  18. Inspect for proper operation.

J 38185 Hose Clamp Pliers. See Special Tools .

  1. Remove the air cleaner intake duct.
  2. Partially drain the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  3. Use the J 38185 to reposition the hose clamp from the water outlet housing. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  4. Remove the radiator inlet hose from the water outlet housing.
  5. Remove the exhaust crossover pipe. Refer to «Exhaust Crossover Pipe Replacement (3.4L)»(/chevrolet/monte-carlo/vi-1999-2007/remont/exhaust/#engine-exhaust-system) or «Exhaust Crossover Pipe Replacement (3.8L)»(/chevrolet/monte-carlo/vi-1999-2007/remont/exhaust/#engine-exhaust-system) in Engine Exhaust.
  6. Remove the water outlet housing bolts.
  7. Remove the water outlet housing and the gasket.
  8. Remove the thermostat.
  9. Clean the water outlet mating surfaces.
  1. Install the thermostat.
  2. Install the water outlet gasket and housing.
  3. Install the water outlet housing bolts. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
  4. Install the exhaust crossover pipe. Refer to «Exhaust Crossover Pipe Replacement (3.4L)»(/chevrolet/monte-carlo/vi-1999-2007/remont/exhaust/#engine-exhaust-system) or «Exhaust Crossover Pipe Replacement (3.8L)»(/chevrolet/monte-carlo/vi-1999-2007/remont/exhaust/#engine-exhaust-system) in Engine Exhaust.
  5. Install the radiator inlet hose to the water outlet housing.
  6. Use the J 38185 to reposition and install the hose clamp to the water outlet housing. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  7. Install the air cleaner intake duct.
  8. Fill the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .

J 38185 Hose Clamp Pliers. See Special Tools .

  1. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/chevrolet/monte-carlo/vi-1999-2007/remont/mechanical/#engine-mechanical-38l-l36) in Engine Mechanical - 3.8L.
  2. Partially drain the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  3. Use the J 38185 to reposition the hose clamp from the water outlet housing. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  4. Remove the radiator inlet hose from the water outlet housing.
  5. Remove the water outlet housing bolt and the stud.
  6. Remove the water outlet housing and the gasket.
  7. Remove the thermostat.
  8. Inspect and clean the water outlet housing mating surfaces.
  1. Install the thermostat.
  2. Install the gasket and the water outlet housing.
  3. Install the water outlet housing bolt and the stud. Tighten: Tighten the bolt and the stud to 27 N.m (20 lb ft).
  4. Install the radiator inlet hose to the water outlet housing.
  5. Use the J 38185 to reposition install the hose clamp to the water outlet housing. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  6. Fill the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  7. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/chevrolet/monte-carlo/vi-1999-2007/remont/mechanical/#engine-mechanical-38l-l36) in Engine Mechanical - 3.8L.

J 38185 Hose Clamp Pliers. See Special Tools .

  1. Partially drain the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  2. Remove the air cleaner intake duct.
  3. Remove the LH engine mount strut. Refer to «Engine Mount Strut Replacement - Left»(/chevrolet/monte-carlo/vi-1999-2007/remont/mechanical/#engine-mechanical-38l-l36) in Engine Mechanical - 3.4L.
  4. Remove the spark plugs wires from the left side spark plugs.
  5. Use the J 38185 to reposition the radiator inlet hose clamp from the water outlet housing. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  6. Remove the radiator inlet hose from the water outlet housing.
  7. Remove the heater outlet hose (2) from the thermostat bypass pipe.
  8. Remove the throttle body inlet (3) and outlet (4) hoses from the thermostat bypass pipe.
  9. Remove the thermostat bypass pipe nut.
  10. Remove the thermostat bypass pipe hose and clamp from the thermostat bypass pipe.
  11. Remove the thermostat bypass pipe bolt.
  12. Remove the thermostat bypass pipe.
  1. Install the thermostat bypass pipe.
  2. Install the thermostat bypass pipe bolt. Tighten: Tighten the bolt to 11 N.m (98 lb in).
  3. Install the thermostat bypass pipe hose and clamp to the thermostat bypass pipe.
  4. Install the thermostat bypass pipe nut. Tighten: Tighten the nut to 25 N.m (18 lb ft).
  5. Install the heater outlet hose (2) and the clamp to the thermostat bypass pipe.
  6. Install the throttle body inlet (3) and outlet (4) hoses and the clamps to the thermostat bypass pipe.
  7. Install the radiator inlet hose to the water outlet housing.
  8. Use the J 38185 to reposition and install the radiator inlet hose clamp to the water outlet housing. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  9. Install the spark plugs wires to the left side spark plugs.
  10. Install the LH engine mount strut. Refer to «Engine Mount Strut Replacement - Left»(/chevrolet/monte-carlo/vi-1999-2007/remont/mechanical/#engine-mechanical-38l-l36) in Engine Mechanical - 3.4L.
  11. Install the air cleaner intake duct.
  12. Fill the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  1. Drain the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  2. Remove the drive belt shield bolt.
  3. Remove the drive belt shield.
  4. Loosen the water pump pulley bolts.
  5. Remove the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/monte-carlo/vi-1999-2007/remont/mechanical/#engine-mechanical-34l-v6-vin-e-la1) in Engine Mechanical - 3.4L.
  6. Remove the water pump pulley bolts.
  7. Remove the water pump pulley.
  8. Remove the water pump bolts.
  9. Remove the water pump (1).
  10. Remove the water pump gasket (2).
  11. Clean the water pump gasket mating surfaces.
  1. Install the water pump gasket (2).
  2. Install the water pump (1).
  3. Install the water pump bolts. Tighten: Tighten the bolts to 10 N.m (89 lb in).
  4. Install the water pump pulley.
  5. Install the water pump pulley bolts. Tighten: Tighten the bolts to 25 N.m (18 lb in).
  6. Install the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/monte-carlo/vi-1999-2007/remont/mechanical/#engine-mechanical-34l-v6-vin-e-la1) in Engine Mechanical - 3.4L.
  7. Install the drive belt shield.
  8. Install the drive belt shield bolt. Tighten: Tighten the bolt to 10 N.m (89 lb in).
  9. Fill the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  1. Drain the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  2. Loosen the water pump pulley bolts.
  3. Remove the drive belt. Refer to «Drive Belt Replacement (L32)»(/chevrolet/monte-carlo/vi-1999-2007/remont/mechanical/#engine-mechanical-38l-l36) in Engine Mechanical - 3.8L.
  4. Remove the water pump pulley bolts.
  5. Remove the water pump pulley.
  6. Remove the power steering pump and reposition. Refer to «Power Steering Pump Replacement (3.4L)»(/chevrolet/monte-carlo/vi-1999-2007/remont/manual-power-steering/#rack-pinion-power-steering-system) or «Power Steering Pump Replacement (3.8L)»(/chevrolet/monte-carlo/vi-1999-2007/remont/manual-power-steering/#rack-pinion-power-steering-system) in Power Steering System.
  7. Remove the water pump bolts.
  8. Remove the water pump.
  9. Remove the water pump gasket.
  10. Clean and inspect the water pump mating surfaces.
  1. Install the water pump gasket.
  2. Install the water pump.
  3. Install the water pump bolts. Tighten: Tighten the long water pump bolts to 34 N.m (25 lb ft). Tighten the short water pump bolts to 22 N.m (16 lb ft).
  4. Install the water pump pulley.
  5. Install the water pump pulley bolts. Tighten: Tighten the bolts to 13 N.m (115 lb in).
  6. Install the power steering pump. Refer to «Power Steering Pump Replacement (3.4L)»(/chevrolet/monte-carlo/vi-1999-2007/remont/manual-power-steering/#rack-pinion-power-steering-system) or «Power Steering Pump Replacement (3.8L)»(/chevrolet/monte-carlo/vi-1999-2007/remont/manual-power-steering/#rack-pinion-power-steering-system) in Power Steering System.
  7. Install the drive belt. Refer to «Drive Belt Replacement (L32)»(/chevrolet/monte-carlo/vi-1999-2007/remont/mechanical/#engine-mechanical-38l-l36) in Engine Mechanical - 3.8L.
  8. Fill the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  1. Drain the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  2. Remove the radiator drain plug and seal. The seal usually comes out attached to the plug.
  3. Remove the body of the drain plug. Use your fingers or needlenose pliers to disengage the locking tangs from the side tank.
  4. Clean the drain and the drain plug.
  1. Install the seal on the drain plug stem.
  2. Install the drain plug. Make sure that the body is fully seated in the side tank and that the locking tangs are engaged.
  3. Fill the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .

J 38185 Hose Clamp Pliers. See Special Tools .

  1. Remove the battery. Refer to «Battery Replacement»(/chevrolet/monte-carlo/vi-1999-2007/remont/body-electrical/#battery-charging-system-starting-system) in Engine Electrical.
  2. Remove the upper diagonal brace from the right front fender. Refer to «Brace Replacement - Front Fender Upper Diagonal»(/chevrolet/monte-carlo/vi-1999-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
  3. Drain the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  4. Remove the cooling fan and shroud. Refer to «Cooling Fan and Shroud Replacement»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  5. Remove the lower air deflector. Refer to «Radiator Air Baffle and Deflector Replacement - Lower»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  6. Use J 38185 to remove the outlet hose clamp from the radiator. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  7. Remove the outlet hose from the radiator.
  8. Remove the coolant reservoir hose from the radiator overflow neck.
  9. Disconnect the transaxle oil cooler pipes from the radiator.
  10. Pull the plastic cap back from the quick connect fitting and down along the transaxle oil cooler line.
  11. Using a bent-tip screwdriver, pull on one of the open ends of the retaining ring in order to rotate the retaining ring around the quick connect fitting until the retaining ring is out of position and can be completely removed.
  12. Remove and discard the old retaining ring from the quick connect fitting.
  13. Pull the transaxle oil cooler pipe straight out from the quick connect fitting.
  14. Lower the vehicle.
  15. Remove the radiator.
  1. Install the radiator to the lower mounts.
  2. Install the transaxle oil cooler pipes.
  3. Install a NEW retaining ring onto the fitting.
  4. Hook one of the open ends of the retaining ring into one of the slots in the quick connect fitting.
  5. Rotate the retaining ring around the fitting until the retaining ring is positioned with all 3 ears through the 3 slots on the fitting.
  6. Ensure that the three retaining ring ears are seen from inside the fitting and that the retaining ring moves freely in the fitting slots.
  7. Install the transaxle oil cooler pipes into the radiator quick connect fitting.
  8. Insert the ends of the pipe into the quick connect fitting until you hear or feel a click.
  9. Pull back sharply on the pipe in order to ensure that the pipe is fastened into the quick connect fitting.
  10. Position the plastic cap onto the fitting. Do not manually depress the retaining ring when installing the plastic cap onto the quick connect fitting.
  11. Fully seat the plastic cap against the fitting.
  12. Allow no gap between the cap and the fitting.
  13. Ensure that the yellow identification band on the tube is hidden within the quick connect fitting. A hidden yellow identification band indicates proper joint seating.
  14. Install the outlet hose to the radiator.
  15. Install the coolant reservoir hose to the radiator overflow neck.
  16. Use J 38185 to install the outlet hose clamp to the radiator. See «Special Tools»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
  17. Install the lower air deflector. Refer to «Radiator Air Baffle and Deflector Replacement - Lower»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  18. Install the fan shroud. Refer to «Cooling Fan and Shroud Replacement»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  19. Install the battery. Refer to «Battery Replacement»(/chevrolet/monte-carlo/vi-1999-2007/remont/body-electrical/#battery-charging-system-starting-system) in Engine Electrical.
  20. Install the upper diagonal brace to the right front fender. Refer to «Brace Replacement - Front Fender Upper Diagonal»(/chevrolet/monte-carlo/vi-1999-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
  21. Fill the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  22. Adjust the transaxle fluid level.
  1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/monte-carlo/vi-1999-2007/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
  2. Remove the radiator lower air deflector bolts.
  3. Remove the radiator lower air deflector.
  1. Install the radiator lower air deflector.
  2. Install the radiator lower air deflector bolts. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
  3. Lower the vehicle.
  1. Remove the radiator side air deflector retainers. Reposition the ambient temperature sensor.
  2. Remove the radiator side air deflectors.
  1. Position the radiator side air deflectors to the vehicle. Position the ambient temperature sensor to the proper location.
  2. Install the radiator side air deflector retainers.
  1. Remove the radiator air baffle retainers.
  2. Tilt the rear of air baffle upward slightly. Slide the air baffle rearward in order to disengage the upper and lower clips of the air baffle from the fascia support.
  3. Remove the radiator air baffle.
  1. Position the radiator air baffle to the vehicle. Tilt the rear of the air baffle upward slightly. Position the upper clip of the air baffle to the lower edge of the front fascia support C-channel.
  2. Slide the baffle towards the front of the vehicle in order to completely engage the upper and lower clips of the baffle onto the fascia support.
  3. Align the tabs at the rear of the air baffle to the openings in the upper radiator support.
  4. Install the radiator air baffle retainers.
  1. Drain the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  2. Disconnect the coolant heater cord from the coolant heater.
  3. Remove the engine block heater screw.
  4. Remove the engine block heater.
  5. Clean the engine block heater opening.
  1. Apply a coat of GM P/N 12346004, (Canadian P/N 10953480) thread sealant with Teflon or equivalent to the following: The engine block heater seal The cleaned surface of the engine block heater hole
  2. Position the heating element at the 3 o'clock position (2).
  3. Install the engine block heater.
  4. Install the engine block heater screw. Tighten: Tighten the screw to 2 N.m (18 lb in).
  5. Connect the coolant heater cord to the coolant heater.
  6. Lower the vehicle.
  7. Fill the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  1. Drain the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  2. Disconnect the coolant heater cord from the coolant heater.
  3. Loosen the bolt at the coolant heater but do not remove.
  4. Remove the coolant heater.
  5. Remove and clean any burrs, compound, paint, or rough spots from the core plug hole.
  1. Apply a coat of GM P/N 12346004, (Canadian P/N 10953480) thread sealant with Teflon or equivalent to the O-ring and clean the surface of the plug opening.
  2. Install the coolant heater by pushing tight to the block.
  3. Install the coolant heater so the element is at the 9 o'clock position (2).
  4. Tighten the coolant heater bolt until both locking wings draw tight against the inner wall of the engine block. Tighten: Tighten the bolt to 2 N.m (17 lb in).
  5. Connect the coolant heater cord to the coolant heater.
  6. Fill the cooling system. Refer to «Draining and Filling Cooling System»(/chevrolet/monte-carlo/vi-1999-2007/remont/cooling-system-mechanical/#engine-cooling-system) .
  1. Remove the coolant heater cord retainer from the upper radiator support.
  2. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/monte-carlo/vi-1999-2007/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
  3. Cut the coolant heater cord retaining straps from the engine wiring harness.
  4. Disconnect the coolant heater cord from the coolant heater.
  5. Lower the vehicle.
  6. Remove the coolant heater cord from the vehicle.
  1. Install the coolant heater cord to the vehicle.
  2. Raise the vehicle.
  3. Connect the coolant heater cord to the coolant heater.
  4. Install new retaining straps to the coolant heater cord and the engine wiring harness.
  5. Lower the vehicle.
  6. Install the coolant heater cord retainer to the upper radiator support.
  1. Remove the coolant heater cord retainer from the upper radiator support.
  2. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/monte-carlo/vi-1999-2007/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
  3. Cut the coolant heater cord retaining straps from the engine wiring harness.
  4. Disconnect the coolant heater cord from the coolant heater.
  5. Lower the vehicle.
  6. Remove the coolant heater cord from the vehicle.
  1. Install the coolant heater cord to the vehicle.
  2. Raise the vehicle.
  3. Connect the coolant heater cord to the coolant heater.
  4. Install new retaining straps to the coolant heater cord and the engine wiring harness.
  5. Lower the vehicle.
  6. Install the coolant heater cord retainer to the upper radiator support.

Cooling Fan Control 3.4L (LA1)

The engine cooling fans are controlled by the body control module (BCM) and the powertrain control module (PCM). The BCM sends a Class 2 message to the PCM requesting cooling fan operation. If there is a Class 2 communication malfunction between the BCM and the PCM. The PCM will operate the engine cooling fans independently of the BCM.

The engine cooling fan system consists of 2 electrical cooling fans and 3 fan relays. The relays are arranged in a series/parallel configuration that allows the PCM to operate both fans together at low or high speeds. The cooling fans and fan relays receive battery positive voltage from the engine wiring harness junction block. The ground path is provided at G101.

During low speed operation, the PCM supplies the ground path for the low speed fan relay through the low speed cooling fan relay control circuit. This energizes the FAN CONT #1 relay coil, closes the relay contacts, and supplies battery positive voltage from the FAN CONT #1 fuse through the cooling fan motor supply voltage circuit to the right cooling fan. The ground path for the right cooling fan is through the FAN CONT #2 relay and the left cooling fan. The result is a series circuit with both fans running at low speed.

During high speed operation the PCM supplies the ground path for the FAN CONT #1 relay through the low speed cooling fan relay control circuit. After a 3-second delay, the PCM supplies a ground path for the FAN CONT #2 relay and the FAN CONT #3 relay through the high speed cooling fan relay control circuit. This energizes the FAN CONT #2 relay coil, closes the relay contacts, and provides a ground path for the right cooling fan. At the same time the FAN CONT #3 relay coil is energized closing the relay contacts and provides battery positive voltage from the FAN CONT #2 fuse on the cooling fan motor supply voltage circuit to the left cooling fan. During high speed fan operation, both engine cooling fans have there own ground path. The result is a parallel circuit with both fans running at high speed.

The BCM will request low speed cooling fan operation from the PCM under the following conditions

  1. Engine coolant temperature exceeds approximately 103°C (217°F).
  2. When A/C is requested and the ambient temperature is more than 10°C (50°F).
  3. A/C refrigerant pressure exceeds 1310 kPa (190 psi).
  4. After the vehicle is shut off if the engine coolant temperature at key-off is more than 117°C (243°F) and system voltage is more than 12 volts. The fans will stay on for approximately 3 minutes.

The BCM will request high speed cooling fan operation from the PCM under the following conditions

  1. Engine coolant temperature reaches 110°C (230°F).
  2. A/C refrigerant pressure exceeds 1655 kPa (240 psi).
  3. When certain DTCs set.

Cooling Fan Control 3.8L (L36)

The engine cooling fans are controlled by the body control module (BCM) and the powertrain control module (PCM). The BCM sends a Class 2 message to the PCM requesting cooling fan operation. If there is a Class 2 communication malfunction between the BCM and the PCM. The PCM will operate the engine cooling fans independently of the BCM.

The engine cooling fan system consists of 2 electrical cooling fans and 3 fan relays. The relays are arranged in a series/parallel configuration that allows the PCM to operate both fans together at low or high speeds. The cooling fans and fan relays receive battery positive voltage from the engine wiring harness junction block. The ground path is provided at G101.

During low speed operation, the PCM supplies the ground path for the low speed fan relay through the low speed cooling fan relay control circuit. This energizes the FAN CONT #1 relay coil, closes the relay contacts, and supplies battery positive voltage from the FAN CONT #1 fuse through the cooling fan motor supply voltage circuit to the right cooling fan. The ground path for the right cooling fan is through the FAN CONT #2 relay and the left cooling fan. The result is a series circuit with both fans running at low speed.

During high speed operation the PCM supplies the ground path for the FAN CONT #1 relay through the low speed cooling fan relay control circuit. After a 3-second delay, the PCM supplies a ground path for the FAN CONT #2 relay and the FAN CONT #3 relay through the high speed cooling fan relay control circuit. This energizes the FAN CONT #2 relay coil, closes the relay contacts, and provides a ground path for the right cooling fan. At the same time the FAN CONT #3 relay coil is energized closing the relay contacts and provides battery positive voltage from the FAN CONT #2 fuse on the cooling fan motor supply voltage circuit to the left cooling fan. During high speed fan operation, both engine cooling fans have there own ground path. The result is a parallel circuit with both fans running at high speed.

The BCM will request low speed cooling fan operation from the PCM under the following conditions

  1. Engine coolant temperature exceeds approximately 100°C (212°F).
  2. When A/C is requested and the ambient temperature is more than 10°C (50°F).
  3. A/C refrigerant pressure exceeds 1310 kPa (190 psi).
  4. After the vehicle is shut off if the engine coolant temperature at key-off is more than 117°C (243°F) and system voltage is more than 12 volts. The fans will stay on for approximately 4 minutes.

The BCM will request high speed cooling fan operation from the PCM under the following conditions

  1. Engine coolant temperature reaches 105°C (221°F).
  2. A/C refrigerant pressure exceeds 1655 kPa (240 psi).
  3. When certain DTCs set.

Engine Coolant Indicator(s)

TEMP

  1. The IPC illuminates the TEMP indicator when the PCM determines that the coolant temperature is greater than 128°C (262°F). The IPC receives a discrete input from the PCM requesting illumination.
  2. The IPC performs the displays test at the start of each ignition cycle. The IPC illuminates the TEMP indicator.

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.

The cooling system's 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 system cools slowly or not at all. This allows the engine to warm quickly.

Cooling Cycle

Coolant is drawn from the radiator outlet and into the water pump inlet by the water pump. Some coolant will then be pumped from the water pump, to the heater core, then back to the water pump. This provides the passenger compartment with heat and defrost.

Coolant is also pumped through 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 is then forced 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.

Coolant is also directed to the throttle body. There it circulates through passages in the casting. During initial warm-up, the coolant assists in warming the throttle body. During normal operating temperatures, the coolant assists in keeping the throttle body cool.

From the cylinder heads, the coolant is then forced to the thermostat. The flow of coolant will either be stopped at the thermostat until the engine is warmed, or it will flow through the thermostat and into the radiator where it is cooled and the coolant cycle is completed.

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 clean drinkable 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 crossflow tube and fin design. This is a series of tubes that extend side to side from the inlet tank to the outlet tank. Fins are placed around the outside of the tubes to improve heat transfer from the coolant to the atmosphere. The inlet and outlet tanks are molded with a high temperature, nylon reinforced plastic. A high temperature rubber gasket seals the tank flange edge. 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 which is located in the bottom of the left hand tank. The drain cock includes the drain cock and drain cock seal.

The radiator removes heat from the coolant passing through it. The fins on the core absorb heat from the coolant passing through the tubes. As air passes between the fins, it absorbs heat and cools the coolant.

During vehicle use, the coolant heats and expands. The coolant that is displaced by this expansion flows into the surge tank. As the coolant circulates, air is allowed to exit. This is an advantage to the cooling system. Coolant without bubbles absorbs heat much better than coolant with bubbles.

Pressure Cap

The pressure cap is a cap that seals and pressurizes 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 of predetermined strength, which protects the radiator by relieving pressure if it exceeds 15 psi. 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 to collapse.

The pressure cap allows pressure in the cooling system to build up. As the pressure builds, the boiling point of the coolant goes up as well. Therefore, the 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 moves from the radiator to the cooler, passing air. The pressure in the cooling system can get too high, however. When the pressure exceeds the strength of the spring, it raises the pressure valve so that the excess pressure can escape. 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 cooling system. This equalizes the pressure in the cooling system with atmospheric pressure, preventing the radiator 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, is allowed 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.

Air Baffles and Seals

The cooling system uses deflectors, air baffles and air seals to increase system cooling. Deflectors are installed under the vehicle to redirect airflow beneath the vehicle to flow through the radiator and increase cooling. Air baffles are also used to direct airflow into the radiator and increase cooling. Air seals prevent air from bypassing the radiator and A/C condenser. Air seals also prevent recirculation of the 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 a flat plate mounted on the pump shaft with a series of flat or curved blades or vanes. 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. These sealed bearings never need to be lubricated. With a sealed bearing, grease cannot leak out, and dirt and water cannot get in.

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. It's purpose is to regulate the operating temperature of the engine. It utilizes a temperature sensitive wax-pellet element. The element connects to a valve through a piston. When the element is heated, it expands and exerts pressure against a rubber diaphragm. 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 91°C (195°F), the thermostat valve remains closed. This prevents circulation of the coolant to the radiator and allows the engine to warm up quickly. After the coolant temperature reaches 91°C (195°F), 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, even 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.

Engine Oil Cooler

The engine oil cooler is a heat exchanger. It is located inside the left side end tank of the radiator. The engine oil temperature is controlled by the temperature of the engine coolant that surrounds the oil cooler in the radiator.

The engine oil pump, pumps the oil through the engine oil cooler line to the oil cooler. The oil then flows through the cooler where the engine coolant absorbs heat from the oil. The oil is then pumped through the oil cooler return line, to the oil filter, to the engine block oil system.

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 that surrounds the oil cooler as the transmission fluid passes down through the cooler.

The transmission oil pump, pumps the fluid through the transmission oil cooler feed line to the oil cooler. The fluid then flows down through the cooler while the engine coolant absorbs heat from the fluid. The fluid is then pumped through the transmission oil cooler return line, to the transmission.

Special Tools

Special Tools Illustration Tool Number/ Description J 23688 Coolant and Battery Fluid Tester J 24460-01 Cooling System Pressure Tester J 24731 Tempil Stick J 38185 Hose Clamp Pliers J 42971 Quick Connect Release Tool

Scheme 3

Scheme 3: Special Tools

Scheme 4

Scheme 4

Scheme 5

Scheme 5

See also:
Scan Tool Does Not Power Up
Testing for Intermittent Conditions and Poor Connections
Circuit Testing
Wiring Repairs
Connector Repairs
Checking Aftermarket Accessories
Instrument Panel Cluster (IPC) Replacement
Drive Belt Tensioner Replacement
Drive Belt Tensioner Replacement
Heater Core Replacement
Engine Will Not Crank - Crankshaft Will Not Rotate
Coolant in Combustion Chamber
Coolant in Engine Oil
Coolant in Combustion Chamber
Coolant in Engine Oil
Lower Engine Noise, Regardless of Engine Speed
Lower Engine Noise, Regardless of Engine Speed
Cylinder Leakage Test
Lifting and Jacking the Vehicle
Fastener Notice
Brace Replacement - Cross Vehicle
Battery Negative Cable Disconnect/Connect Procedure
Exhaust Crossover Pipe Replacement (3.4L)
Power Steering Pump Replacement (3.4L)
Diagnostic System Check - Engine Cooling
Symptoms - Engine Cooling
Diagnostic Trouble Code (DTC) List
Cooling System Connector End Views
Engine Coolant Temperature Indicator Always On
Cooling Fan Always On
Cooling Fan Inoperative
Coolant Heater Inoperative
Engine Overheating
Loss of Coolant
Thermostat Diagnosis (Overheating)
Thermostat Diagnosis (Slow to heat)
Engine Fails To Reach Normal Operating Temperature
Special Tools
Flushing
Cooling System Leak Testing
Pressure Cap Testing