Engine Cooling - Evolution Mitsubishi Lancer Evolution VIII

GENERAL DESCRIPTION

The cooling system is designed to keep every part of the engine at appropriate temperature in whatever condition the engine may be operated. The cooling method is of the water-cooled, pressure forced circulation type in which the water pump pressurizes coolant and circulates it throughout the engine. If the engine coolant temperature exceeds the prescribed temperature, the thermostat opens to circulate the coolant through the radiator as well so that the heat absorbed by the coolant may be radiated into the air. The water pump is of the centrifugal type and is driven by the drive belt from the crankshaft. The radiator is the corrugated fin, down flow type. The cooling fan is controlled by the fan control module and engine control module depend on driving conditions.

Scheme 142

Scheme 143

INTRODUCTION

The system cools the engine so that it does not overheat and maintains the engine at an optimum temperature. The system components are the radiator, water pump, thermostat, cooling fan. Possible faults include low coolant, contamination, belt loosening and component damage.

TROUBLESHOOTING STRATEGY

Use these steps to plan your diagnostic strategy. If you follow them carefully, you will be sure to find most of the engine cooling faults.

1. Gather information from the customer.
2. Verify that the condition described by the customer exists.
3. Find and repair the malfunction by following the «SYMPTOM CHART»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/cooling-system-mechanical/#engine-cooling-evolution) .
4. Verify that the malfunction is eliminated.

Scheme 144

Scheme 145

1. STEP 1. Check for coolant leaks. WARNING: When pressure testing the cooling system, slowly release cooling system pressure to avoid getting burned by hot coolant. CAUTION: Be sure to completely clean away any moisture from the places checked. When the tester is removed, be careful not to spill any coolant. When installing and removing the tester and when testing, be careful not to deform the filler neck of the radiator. Check that the coolant level is up to the filler neck. Install a radiator tester and apply 160 kPa (23 psi) pressure, and then check for leakage from the radiator hose or connections. Q: Is leakage present from the radiator hose or connections? YES: Repair or replace the appropriate part, then go to Step 2. NO: There is no action to be taken.
2. STEP 2. Retest the system. Q: It there still coolant leakage? YES: Return to Step 1 . NO: The procedure is complete.

Scheme 146

1. STEP 1. Remove the radiator cap and check for coolant contamination. Q: Is the coolant contaminated with rust and oil? YES: Replace it. Refer to «ENGINE COOLANT REPLACEMENT»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/cooling-system-mechanical/#engine-cooling-evolution__engine-coolant-replacement) . NO: There is no action to be taken. Go to Step 2.
2. STEP 2. Check the radiator cap valve opening pressure. NOTE: Be sure that the cap is clean before testing. Rust or other foreign material on the cap seal will cause an improper reading. Use a cap adapter to attach the cap to the tester. Increase the pressure until the gauge indicator stops moving. Minimum limit: 83 kPa (12 psi) Standard value: 93-123 kPa (14-18 psi) Q: Does the reading remain at or above the minimum limit? YES: Go to Step 3. NO: Replace the radiator cap. Then go to Step 5 .
3. STEP 3. Check thermostat operation. Refer to «THERMOSTAT CHECK»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/cooling-system-mechanical/#engine-cooling-evolution) . Q: Does the thermostat operate correctly? YES: Go to Step 4. NO: Replace the thermostat, then go to Step 5.
4. STEP 4. Check the drive belt for slippage or damage. Refer to «8. DRIVE BELT (FOR GENERATOR, WATER PUMP AND POWER STEERING OIL PUMP (CHECK CONDITION)»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/oem-general-information/#general-evolution) . Q: Is the drive belt loose or damaged? YES: Replace the drive belt, then go to Step 5. NO: There is no action to be taken.
5. STEP 5. Retest the system. Check the engine coolant temperature. Q: Is the engine coolant temperature abnormally high? YES: Return to Step 2 . NO: The procedure is complete.

Scheme 147

Scheme 148

CIRCUIT OPERATION

1. The fan control module is powered from fusible link number 2.
2. The engine control module (ECM) judges the required revolution speed of cooling fan motor using the input signals transmitted from A/C switch, vehicle speed sensor and engine coolant temperature sensor. The ECM activates the fan control module to drive the cooling fan motor.

TECHNICAL DESCRIPTION

1. The cause could be a malfunction of the fan control module power supply or ground circuit.
2. The cause could also be a malfunction of the fan control module or the ECM.

TROUBLESHOOTING HINTS

1. Malfunction of fusible link
2. Malfunction of fan control relay
3. Malfunction of cooling fan motor
4. Malfunction of fan control module
5. Malfunction of ECM
6. Damaged wiring harness or connector

DIAGNOSIS

Required Special Tool

1. MB991223: Harness Set

Scheme 149

Scheme 150

Scheme 151

Scheme 152

Scheme 153

Scheme 154

Scheme 155

Scheme 156

Scheme 157

Scheme 158

Scheme 159

Scheme 160

Scheme 161

Scheme 162

Scheme 163

Scheme 164

Scheme 165

Scheme 166

Scheme 167

1. STEP 1. Check the circuit at fan control module connector A-17 terminal 3. Disconnect fan control module connector A-17, and measure at the harness side connector. Measure the voltage between terminal number 3 and ground. When the ignition switch is turned to the "ON" position, voltage should measure battery positive voltage. Q: Is the voltage battery positive voltage when the ignition switch is turned to the "ON" position? YES: Go to Step 7 . NO: Go to Step 2.
2. STEP 2. Check the fan control relay. Refer to «FAN CONTROL RELAY CONTINUITY CHECK»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/cooling-system-mechanical/#engine-cooling-evolution) . Q: Is the fan control relay in good condition? YES: Go to Step 3. NO: Replace it, then go to Step 1 .
3. STEP 3. Check for harness damage between fusible link number 2 and fan control relay connector A-09X terminal 4. Q: Are the harness wires between fusible link number 2 and fan control relay connector A-09X damaged? YES: Repair or replace them, then go to Step 13 . NO: Go to Step 4.
4. STEP 4. Check for harness damage between fan control relay connector A-09X terminal 2 and fan control module connector A-17 terminal 3. Q: Are the harness wires between fan control relay connector A-09X terminal 2 and fan control module connector A-17 terminal 3 damaged? YES: Repair or replace them, then go to Step 13 . NO: Go to Step 5.
5. STEP 5. Check for harness damage between joint connector (6) C-105 and fan control relay connector A-09X. NOTE: After inspecting intermediate connector A-13 terminal 3 and joint connector (6) C-105 terminal 28, 33 inspect the wires. If intermediate connector A-13 and joint connector (6) C-105 are damaged, repair or replace them. Refer to «HARNESS CONNECTOR INSPECTION»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/oem-general-information/#general-evolution) . Q: Are the harness wires between joint connector (6) C-105 terminal 28 and fan control relay connector A-09X terminal 1 damaged? YES: Repair or replace them, then go to Step 13 . NO: Go to Step 6.
6. STEP 6. Check for harness damage between fan control relay connector A-09X terminal 3 and ground. Q: Are the harness wires between fan control relay connector A-09X terminal 3 and ground damaged? YES: Repair or replace them, then go to Step 13 . NO: Go to Step 7.
7. STEP 7. Check the cooling fan motor. Refer to «COOLING FAN MOTOR CHECK»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/cooling-system-mechanical/#engine-cooling-evolution) . Q: Is the cooling fan motor in good condition? YES: Go to Step 8. NO: Replace it, then go to Step 13 .
8. STEP 8. Check the circuit at fan control module connector A-17 terminal 1. Disconnect fan control module connector A-17, and measure at the harness side connector. Measure the resistance between terminal number 1 and ground. The resistance should measure less than 2 ohms. Q: Is the resistance less than 2 ohms? YES: Go to Step 10 . NO: Go to Step 9.
9. STEP 9. Check the harness wire between fan control module connector A-17 and ground. Q: Are the harness wires between fan control module connector A-17 and ground damaged? YES: Repair or replace them, then go to Step 13 . NO: Go to Step 10.
10. STEP 10. Measure the output circuit voltage at ECM connector C-121 terminal 21 by backprobing. Do not disconnect ECM connector C-121. Start the engine and allow it to idle. Turn the A/C switch to the "ON" position. Measure the voltage between terminal number 21 and ground by backprobing. The voltage should measure 0.7 volt or more when the cooling fan is operating. Q: Is the voltage 0.7 volt or more when the cooling fan is operating? YES: Go to Step 12 . NO: Go to Step 11.
11. STEP 11. Check the harness wire between ECM connector C-121 and fan control module connector A-17. NOTE: If intermediate connector A-13 terminal 2 is damaged, repair or replace it. Refer to «HARNESS CONNECTOR INSPECTION»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/oem-general-information/#general-evolution) . Q: Are the harness wires between ECM connector C-121 terminal 21 and fan control module connector A-17 terminal 2 damaged? YES: Repair or replace them, then go to Step 13 . NO: Go to Step 12.
12. STEP 12. Check the fan control module at ECM connector C-121. Do not disconnect ECM connector C-121. Pull out terminal number 21. Turn the ignition switch to the "ON" position. Q: Does the cooling fan motor operate? YES: Replace the ECM. Then go to Step 13. NO: Replace the fan control module. Then go to Step 13.
13. STEP 13. Check the symptoms. Q: Does the cooling fan operate correctly? YES: The procedure is complete. NO: Return to Step 1 .

INSPECTION PROCEDURE 4: COOLING FAN DOES NOT CHANGE SPEED OR DOES NOT STOP

Note. If the engine coolant temperature reaches 110°C (230°F) or higher, the cooling fan control runs the cooling fan for up to 5 minutes even after the ignition switch is turned to the "LOCK" (OFF) position [the fan stops its rotation when the engine coolant temperature decreases to 110°C (230°F) or lower.]

COOLING FAN DRIVE CIRCUIT

(Scheme 147)

1. The fan control module is powered from fusible link number 2.
2. The ECM judges the required revolution speed of cooling fan motor using the input signals transmitted from A/C switch, vehicle speed sensor and engine coolant temperature sensor. The ECM activates the fan control module to drive the cooling fan motor.

1. The fan control module has variable control of the cooling fan motor speed using signals transmitted from the ECM.

1. Malfunction of fan control relay
2. Malfunction of fan control module
3. Malfunction of ECM

Required Special Tool

1. MB991223: Harness Set

Scheme 168

Scheme 169

Scheme 170

Scheme 171

Scheme 172

Scheme 173

Scheme 174

Scheme 175

Scheme 176

Scheme 177

Scheme 178

1. STEP 1. Check the fan control relay. Refer to «FAN CONTROL RELAY CONTINUITY CHECK»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/cooling-system-mechanical/#engine-cooling-evolution) . Q: Is the fan control relay in good condition? YES: Go to Step 2. NO: Replace the part, then go to Step 8 .
2. STEP 2. Check the harness wire between fan control relay connector A-09X terminal 2 and fan control module connector A-17 terminal 3. Q: Are the harness wire between fan control relay connector A-09X and fan control module connector A-17 damaged? YES: Repair or replace the part, then go to Step 6 . NO: Go to Step 3.
3. STEP 3. Measure the output circuit voltage at ECM connector C-121 terminal 21 by backprobing. Do not disconnect ECM connector C-121. Start the engine and allow it to idle. Measure the voltage between terminal number 21 and ground by backprobing. The voltage should measure less than 0.3 volt when the cooling fan is not operating. Q: Is the voltage less than 0.3 volt when the cooling fan is not operating? YES: Go to Step 6 . NO: Go to Step 4.
4. STEP 4. Measure the output circuit voltage at ECM connector C-121 terminal 21 by backprobing. Do not disconnect ECM connector C-121. Start the engine and allow it to idle. Turn the A/C switch to the "ON" position. Measure the voltage between terminal number 21 and ground by backprobing. The voltage should measure 0.7 volt or more when the cooling fan is operating. Q: Is the voltage 0.7 volt or more when the cooling fan is operating? YES: Go to Step 6 . NO: Go to Step 5.
5. STEP 5. Check the harness wire between ECM connector C-121 and fan control module connector A-17. NOTE: If intermediate connector A-13 terminal 2 is damaged, repair or replace it. Refer to «HARNESS CONNECTOR INSPECTION»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/oem-general-information/#general-evolution) . Q: Are the harness wires between ECM connector C-121 terminal 21 and fan control module connector A-17 terminal 2 damaged? YES: Repair or replace them, then go to Step 8 . NO: Go to Step 6.
6. STEP 6. Check the fan control module at ECM connector C-121. Do not disconnect ECM connector C-121. Pull out terminal number 21. Turn the ignition switch to the "ON" position. Q: Does the cooling fan motor operate? YES: Replace the ECM. Then go to Step 8 . NO: Go to Step 7.
7. STEP 7. Check the fan control module at ECM connector C-121. Disconnect ECM connector C-121. Pull out terminal number 21. Connect terminal number 21 to the body ground. Turn the ignition switch to the "ON" position. Q: Does the cooling fan motor stop running? YES: Replace the ECM. Then go to Step 8. NO: Replace the fan control module. Then go to Step 8.
8. STEP 8. Check the symptoms. Q: Does the cooling fan operate correctly? YES: The procedure is complete. NO: Return to Step 1 .

ENGINE COOLANT LEAK CHECK

Scheme 179

1. Check that the coolant level is up to the filler neck. Install a radiator tester and apply 160 kPa (23 psi) pressure, and then check for leakage from the radiator hose or connections.
2. If there is leakage, repair or replace the appropriate part.

RADIATOR CAP PRESSURE CHECK

Note. Be sure that the cap is clean before testing. Rust, or other foreign material on the cap seal will cause an improper reading.

Scheme 180

1. Use a cap adapter to attach the cap to the tester.
2. Increase the pressure until the indicator of the gauge stops moving. Minimum limit: 83 kPa (12 psi) Standard value: 93-123 kPa (14-18 psi)
3. Replace the radiator cap if the reading does not remain at or above the minimum limit.

ENGINE COOLANT REPLACEMENT

Required Special Tool

1. MB991871: LLC Changer

Scheme 181

Scheme 182

1. Remove the under cover. WARNING: When removing the radiator cap, use care to avoid contact with hot coolant or steam. Place a shop towel over the cap and turn the cap counterclockwise a little to let the pressure escape through the vinyl tube. After reliving the steam pressure, remove the cap by slowly turning it counterclockwise.
2. Drain the water from the radiator, heater core and engine after unplugging the radiator drain plug and removing the radiator cap.
3. Drain the water in the water jacket by unplugging the drain plug of the cylinder block.
4. Remove the reserve tank and drain the coolant.
5. Drain the cooling water then clean the path of the cooling water by injecting water into the radiator from the radiator cap area.
6. Apply the designated sealant to the screw area of the cylinder block drain plug, and then tighten to the standard torque. Specified sealant: 3M ™ AAD Part No. 8731 or equivalent Tightening torque: 44+/-5 N.m (33+/-3 ft-lb)
7. Securely tighten the drain plug of the radiator.
8. Assemble the reserve tank. CAUTION: Do not use alcohol or methanol anti-freeze or any engine coolants mixed with alcohol or methanol anti-freeze. The use of an improper antifreeze can cause corrosion of the aluminum components.
9. By referring to the section on coolant, select an appropriate concentration for safe operating temperature within the range of 30 to 60%. Use special tool MB991871 to refill the coolant. A convenient mixture is a 50% water and 50% antifreeze solution [freezing point: -31°C (-32.8°F)]. Recommended antifreeze: Mitsubishi Genuine Coolant or equivalent Quantity: 6.0 dm 3 (6.3 quarts) NOTE: For how to use special tool MB991871, refer to its manufacturer's instructions.
10. Reinstall the radiator cap.
11. Start the engine and let it warm up until the thermostat opens.
12. Repeatedly revving the engine up to 3,000 r/min several times, then stop the engine.
13. Remove the radiator cap after the engine has become cold, and pour in coolant up to the brim. Reinstall the cap. CAUTION: Do not overfill the reserve tank.
14. Add coolant to the reserve tank between the "FULL" and "LOW" mark if necessary.
15. Install the under cover.

ENGINE COOLANT CONCENTRATION TEST

Refer to RECOMMENDED LUBRICANTS AND LUBRICANT CAPACITIES .

FAN CONTROL MODULE CHECK

Required Special Tool

1. MB991222: Probe

Scheme 183

Scheme 184

1. Remove the center under cover.
2. Disconnect the fan control module connector.
3. Turn the ignition switch to the "ON" position, and measure the voltage between the harness-side connector terminals. Standard value: Battery positive voltage
4. Turn the ignition switch to the "LOCK" (OFF) position, and connect the fan control module connector.
5. Insert special tool MB991222 at the back of the cooling fan motor connector.
6. Connect special tool MB991222 to the circuit tester.
7. Ensure that the A/C switch is off, and start the engine and run it at idle.
8. Measure the voltage between the cooling fan motor connector terminals. Standard value: 1V or less
9. Turn the A/C switch to the "ON" position. WARNING: Stay clear of the fan when the fan starts running.
10. Measure the voltage between the cooling fan motor connector terminals while the fan is running. The voltage should repeat the values 1) and 2) below. Standard value: 1) 8.2+/-2.6 V 2) Battery positive voltage +/- 2.6 V
11. If the voltage does not repeatedly change as indicated, replace the fan control module.
12. Install the center under cover.

Scheme 185

Scheme 186

Scheme 187

1. Remove the center undercover.
2. Remove the cooling fan motor connector. WARNING: Stay clear of the fan when the fan starts running.
3. Check to see that the fan motor of the radiator turns when applying battery power between the connector terminals of the cooling fan motor. Also check to see that there is no abnormal sound coming from the cooling fan motor at this time.
4. If the cooling fan motor is defective, replace it.
5. Install the center undercover.

Scheme 188

<< A >> RADIATOR UPPER HOSE/RADIATOR LOWER HOSE DISCONNECTION

Make mating marks on the radiator hose and the hose clamp. Disconnect the radiator hose.

Scheme 189

<< B >> AIR PIPE B MOUNTING BOLT REMOVAL

After removing the bolt, position air pipe B out of the way so that the pipe does not interfere with the radiator assembly or the cooling fan motor, the fan and shroud assembly.

Scheme 190

Scheme 191

1. Insert each hose as far as the projection of the water inlet pipe, water outlet fitting or radiator.
2. Align the mating marks on the radiator hose and hose clamp, and then connect the radiator hose.

Scheme 192

<< A >> RADIATOR UPPER HOSE DISCONNECTION

Make mating marks on the radiator hose and the hose clamp. Disconnect the radiator hose.

Scheme 193

>> A << THERMOSTAT INSTALLATION

Install the thermostat being careful not to fold over or scratch the rubber ring.

Scheme 194

1. Remove sealant from the water outlet fitting and cylinder head surfaces.
2. Apply a bead of the sealant to the cylinder head mating surface of the water outlet fitting as shown. Specified sealant: 3M ™ AAD Part No. 8672, 3M ™ AAD Part No. 8679/8678 or equivalent NOTE: Install the water outlet fitting within 15 minutes after applying liquid gasket.
3. Install the water outlet fitting to the cylinder head. CAUTION: Then wait at least one hour. Never start the engine or let engine oil or coolant touch the adhesion surface during that time.
4. Tighten the water outlet fitting mounting bolts to the specified torque. Tightening torque: 10+/-1 N.m (84+/-13 in-lb)

Scheme 195

1. Insert each hose as far as the projection of the water outlet fitting.
2. Align the mating marks on the radiator hose and hose clamp, and then connect the radiator hose.

Scheme 196

Scheme 197

1. Immerse the thermostat in water, and heat the water while stirring. Check the thermostat valve opening temperature. Standard value: Valve opening temperature: 80+/-1.5°C (176+/-3°F)
2. Check that the amount of valve lift is at the standard value when the water is at the full-opening temperature. NOTE: Measure the valve height when the thermostat is fully closed, and use this measurement to compare the valve height when the thermostat is fully open. Standard value: Full-opening temperature: 93°C (199°F) Amount of valve lift: 9.5 mm (0.37 inch) or more

REMOVAL AND INSTALLATION

Scheme 198

>> A << O-RING INSTALLATION

Fit an O-ring into the O-ring groove located at the end of the water inlet pipe and apply water to the O-ring or the inside of the mounting surface of the water pump for insertion.

Scheme 199

Scheme 200

Make mating marks on the radiator hose and the hose clamp. Disconnect the radiator hose.

Scheme 201

Fit an O-ring into the groove of the water inlet pipe and apply water to the circumference of the O-ring or the inside of the mounting surface of the pipe for insertion.

Scheme 202

>> B << WATER INLET PIPE INSTALLATION

After installing the water outlet fitting and thermostat case assembly, tighten the mounting bolt of the water inlet pipe to the specified torque.

1. Tightening torque
2. M6: 5.0+/-1.0 N.m (44+/-9 in-lb)
3. M8: 13+/-2 N.m (111+/-22 in-lb)

Scheme 203

1. Insert each hose as far as the projection of the water inlet pipe or water outlet fitting.
2. Align the mating marks on the radiator hose and hose clamp, and then connect the radiator hose.

>> D << WATER OUTLET FITTING AND THERMOSTAT CASE ASSEMBLY INSTALLATION

1. Remove sealant from the thermostat case and cylinder head surfaces.
2. Apply a bead of the sealant to the cylinder head mating surface of the thermostat case as shown. Specified sealant: 3M ™ AAD Part No. 8672, 3M ™ AAD Part No. 8679/8678 or equivalent NOTE: Install the water outlet fitting and thermostat case assembly within 15 minutes after applying liquid gasket.
3. Install the water outlet fitting and thermostat case assembly to the cylinder head. CAUTION: Then wait at least one hour. Never start the engine or let engine oil or coolant touch the adhesion surface during that time.
4. Tighten the thermostat case mounting bolts to the specified torque. Tightening torque: 23+/-4 N.m (17+/-3 ft-lb)

WATER PIPE AND HOSE CHECK

Check the water pipe and hose for cracks, damage and clogs. Replace them if necessary.

Scheme 204

FASTENER TIGHTENING SPECIFICATIONS

FASTENER TIGHTENING SPECIFICATIONS

Scheme 205

Scheme 206

Scheme 207

See also:
• 8. DRIVE BELT (FOR GENERATOR, WATER PUMP AND POWER STEERING OIL PUMP (CHECK CONDITION)
• SYMPTOM CHART
• ENGINE COOLANT REPLACEMENT