HONDA CIVIC 2003 7.G Workshop Manual

Engine Cooling
Cooling System
Component Location Index ......................................... 10-2
Radiator Cap Test ..................... .......... 10-3
RadiatorTest ............. 10-3
Fan Motor Test .......... l0-4
Thermostat Test ...................... ........... 10-4
Water Pump Inspection ..................... 10-5
Water Pump Replacement ................. 10-5
Coolant Check .............. ....................... 10-6
Coolant Replacement ......................... 10-6
Thermostat Replacement .................. 10-8
Water Passage Installation ................ 10-9
Water Outlet Installation .................... 10-9
Radiator and Fan Replacement ................................... 10-10
Fan Controls
Component Location Index ......................................... 10-11
Symptom Troubleshooting Index ............................... 10-12
Circuit Diagram ......... 10-13
Radiator Fan CircuitTroubleshooting ........................ 10-14
Radiator Fan Switch Circuit Troubleshooting
(Open) ............ ........ 10-16
Radiator Fan Switch Circuit Troubleshooting
(Short) ............ ........ 10-16
Radiator Fan Switch Test ................... 10-17
Radiator Fan Switch Reolacement .............................. 10-17

Cooling System
Component Location Index
WATER PUMPInspection, page 10-5Replacement. page 10-5
RESERVETANK
RADIATORCAP
RAOIATOR FAN SWITCHTest, page 10-17Replacement, page 10'17
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WATER OUTLET,Installation, page'10-g
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CONNECTING PIPE
WATER PASSAGEInstallation, page 10-9
THERMOSTATTest, page 10 4Replacement, page 10 8
RADIATORReplacement, page 10-'l0
RADIATOR FANASSEMgLYReplacement, page 10-10Fan MotorTest, page 10 4A/C CONDENSERFAN ASSEMBLYReplacement, page 10 10Fan Motor Test, page '10-4
10-2
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Radiator Cap Test
1. Remove the radiator cap {A), wet its seal with
engine coolant, then install it on the pressure tester(B) (commercially available).
Apply a pressure of 93 '123 kPa {0.95 1.25
kgf/cm', l4 18 psi).
Check for a drop in pressure.
lf the pressure drops, replace the cap.
3.
4.
Radiator Test
Wait untilthe engine is cool, then carefully remove
the radiator cap and fill the radiator with engine
coolant to the top of the filler neck.
Attach the pressure tester (A) (commercially
available) to the radiator.
1.
3.
4.
Apply a pressure ot 93 '123 kPa (0.95 1 .25
kgf/cm', '14 18 psi).
Inspect for engine coolant leaks and a drop in
pressu re.
Remove the tester, and reinstall the radiator cap.
10-3

Cooling System
Fan Motor Test
1. Disconnect the 2P connectors from the radiator fan
motor and condenser fan motor.
Test the motor by connecting battery power to the
B terminal and ground to the A terminal.
lf the motor fails to run or does not run smoothly,
reptace rL
10-4
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Thermostat Test
Replace the thermostat if it is open at room
remperalure.
To test a closed thermostatl
1. Suspend the thermostat (A) in a container of water.
Do not let the thermometer {B) touch the bottom of
the hot container.
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2.
3.
Heat the water, and check the temDerature with a
thermometer. Check the temperature at which the
thermostat first opens, and at which it is fully open.
Measure the lift height of the thermostat when it is
fullv ooen.
STANDARD THERMOSTAT
Lift height; above 8.0 mm (0.31 in.)
Starts opening: 169 176"F(76 80"C)
Fully open: 194"F {90'Cl
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1.
2.
Water Pump Inspection
Remove the drive belt (see page 4-26),
Turn the water pump pulley counterclockwise.
Check that it turns freely.
Check for signs of seal leakage. A small amount of"weeping" from the bleed holes (A) is normal.
Water Pump Replacement
1. Remove the drive belt (see page 4-26).
2. Drain the engine coolant {see page 10-6).
3. Remove the crankshaft pulley (see page 6-11).
4. Remove the six bolts securing the water pump,
then remove the water pump (A).
6x1.0mm12 N m {1.2 kgt m,8.7 rbf.ft)
Inspect and clean the O-ring groove and mating
surface with the water passage.
Installthe water pump with new O rings in the
reverse order of removal.
7. Clean up any spilled engine coolant.
8. Installthe crankshaft pulley (see page 6-12).
L Refill the radiator with engine coolant, and bleed
air from the cooling system with the heater valve
open {see page 10-6}.
10-5

Cooling System
1 . Look at the coolant level in the reserve tank. Make
sure it is between the MAX mark (A) and MIN mark(B),
Goolant Check
lf the coolant level in the reserve tank is at or below
the MIN mark, add coolant to bring it up to the l\4AX
mark, and inspect the cooling system for leaks.
10-6
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Coolant Replacement
1.
\
Start the engine. Set the heater temperature control
dial to maximum heat. then turn off the ignition
switch. Make sure the engine and radiator are cool
to the touch.
Remove the radiator cap.
Remove the splash shield (see step 23 on page 5-5).
Loosen the drain plug (A), and drain the coolant.
Remove the reserve tank drain cap (A), and drain
the coolant.
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1.
After the coolant has drained, tighten the radiator
drain plug securely. and installthe reserve tank
drain cap securely.
Fill the reserve tank to the MAX mark (A) with
Honda All Season Antifreeze/Coolant Tvpe 2
(P/N O1999-9001).
8. Pour Honda All Season Antifreeze/Coolant Type 2
into the radiator up to the base of the filler neck.
NOTE:. Always use Honda All Season Antifreeze/Coolant
Type 2 {P/N 01999-9001). Using a non-Honda
coolant can result in corrosion, causing the
cooling system to malfunction or fail.. Honda All Season Antifreeze/Coolant Type 2 is a
mixture of 50% antifreeze and 507o water. Pre-
mixing is not required.
Engine Coolant Refill Capacity including the
reserve tank capacity of 0.53 4 (0.56 US gtl :
5.0 0 (s.3 US qt)
Installthe radiator cap loosely.
Start the engine, and let it run until it warms up (the
radiator fan comes on at least twice).
Turn off the engine. Check the level in the radiator,
and add Honda All Season Antifreeze/Coolant Type
2 if needed.
Put the radiator cap on tightly, then run the engine
again and check for leaks.
lnstall the splash shield (see step 22 on page 5-12).
10.
11.
L
tJ.
10-7

Gooling System
Thermostat Replacement
1. Drain the engine coolant (see page 10-6).
2. Remove the splash shield (see step 23 on page 5-5).
3. Remove the lower hose, then remove the thermostat.
6x 1.0 mm9.8 N.m(1.0 kgf.m,7.2lbf ft)
a
u
i*
-
LOWER HOSE
4. Installthe thermostat with a new O-ring, then installthe lower hose.
5. Installthe splash shield (see step 22 on page 5-12).
6. Refillthe radiator with engine coolant, and bleed air from the cooling system with the heater valve open (see page
10_6).
THERMOSTAT
10-8
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Water Passage Installation
1.Clean and dry the water passage mating surfaces.
Apply liquid gasket P/N 08718-0009, evenly to the
cylinder block mating surface ofthewater passage
and to the inner threads of the bolt holes.
NOTE: Do not installthe parts if 5 minutes or more
have elapsed since applying liquid gasket. Instead,
reapply liquid gasket after removing old residue.
3. Installthe water passage (A)with a new O-ring (B).
10 x 1.25 mm44 N m {4.5 kgt m.33 lbf.ft}
4. After assembly, wait at least 30 minutes before
filling the engine with oil.
.t':.:
Water Outlet lnstallation
Installthe water outlet (A)with a new O-ring {B),
12 N m (1.2 kgt m,8,7lbf ft)
10-9

Cooling System
Radiator and Fans Replacement
1. Drain the engine coolant (see page 10-6).
2. Remove the front bumper {see page 20,85).
3. Remove the bulkhead.
4. Remove the upper radiator hose and lower radiator hose.
DRAIN PLUG
UPPER BADIATOR HOSE
BAOIATOA FANASSEMBLY
{
O.RINGRADIATOR CAP
BADIATOB
LOWERCUSHION
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RADIATOR FANswtTcH24Nm{2.1t kgl m. 17lbl hl
LOWER FADIATORHOSE
RESERVETANK
A/C CONDENSERFAN ASSEMBLY
9.8 N m {1.0 kgf m,7.2 lbf ft)CONNECTORSRADIATOB FAN SWITCHCONNECTOB
5. Disconnect the fan motor connectors and radiator fan switch connector, then pull the radiator up and out.
6. Remove the fan shroud assemblies and other parts from the radiator.
7. Installthe radiator in the reverse order of removal. Make sure the upper and lower cushions are set securelV.
8. Install the bulkhead in the reverse order of removal. Apply body paint to the bulkhead mounting bolts.
9. Fill the radiator with engine coolant and bleed the air (see page 10-6).
10-10
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