Honda Civic. Manual — part 386

1. Remove the radiator cap (A). Wet the seal with engine coolant, then install it

on a commercially available pressure tester (B).

Fig. 2: Testing Radiator Cap
Courtesy of AMERICAN HONDA MOTOR CO., INC.

2. Apply a pressure of 93-123 kPa (0.95-1.25 kgf/cm

2

, 14-18 psi).

3. Check for a drop in pressure.
4. If the pressure drops, replace the cap.

RADIATOR TEST

1. Wait until the engine is cool, then carefully remove the radiator cap, and fill

the radiator with engine coolant to the top of the filler neck.

2. Attach a commercially available pressure tester (A) to the radiator, and apply a

pressure of 93-123 kPa (0.95-1.25 kgf/cm

2

, 14-18 psi).

Fig. 3: Testing Radiator
Courtesy of AMERICAN HONDA MOTOR CO., INC.

2008 Honda Civic GX

2006-08 ENGINE Cooling System (R18A1) - Civic (Except Hybrid)

3. Inspect for engine coolant leaks, and a drop in pressure.
4. Remove the tester, then reinstall the radiator cap.
5. Check for engine oil in the coolant and/or coolant in the engine oil.

FAN MOTOR TEST

1. Disconnect the 2P connectors from the radiator fan motor (A) and condenser

fan motor (B).

Fig. 4: Identifying Radiator Fan Motor And Condenser Fan Motor
Courtesy of AMERICAN HONDA MOTOR CO., INC.

2. Test each motor by connecting battery power to the No. 2 terminal and ground

to the No. 1 terminal.

3. If either motor fails to run, or does not run smoothly, replace it (see

RADIATOR AND FAN REPLACEMENT ).

THERMOSTAT TEST

Replace the thermostat if it is open at room temperature.

To test a closed thermostat:

1. Suspend the thermostat (A) in a container of water. Do not let the thermometer

(B) touch the bottom of the hot container.

2008 Honda Civic GX

2006-08 ENGINE Cooling System (R18A1) - Civic (Except Hybrid)

Fig. 5: Checking Temperature When Thermostat Opens
Courtesy of AMERICAN HONDA MOTOR CO., INC.

2. Heat the water and check the temperature with a thermometer. Check the

temperature when the thermostat first opens, then check the temperature when
the thermostat is fully open.

3. Measure the lift height of the thermostat when it is fully open.

Standard Thermostat

Lift Height: Above 8.0 mm (0.31 in.)

Starts Opening: 176-183 °F (80-84 °C)

Fully Open: 203 °F (95 °C)

WATER PUMP INSPECTION

1. Loosen the water pump pulley mounting bolts.

2008 Honda Civic GX

2006-08 ENGINE Cooling System (R18A1) - Civic (Except Hybrid)

Fig. 6: Identifying Water Pump Pulley Mounting Bolts
Courtesy of AMERICAN HONDA MOTOR CO., INC.

2. Remove the drive belt (see DRIVE BELT INSPECTION ).
3. Remove the water pump pulley.

Fig. 7: Identifying Torque Specifications Of Water Pump Pulley Bolts
Courtesy of AMERICAN HONDA MOTOR CO., INC.

4. Turn the water pump counterclockwise. Check that it turns freely. If doesn't

turn smoothly, replace the water pump (see WATER PUMP
REPLACEMENT ).

NOTE:

When you check the water pump, you may see a small

2008 Honda Civic GX

2006-08 ENGINE Cooling System (R18A1) - Civic (Except Hybrid)