2003 HONDA CIVIC engine

Intake Manifold and Exhaust System
Intake Manifold Removal and Installation (cont'dl
5. Be prepared to catch and clean up spilled coolant.
Remove the water bypass hoses, then plug the
water bypass hoses.
6. Relievefuel pressure (see page 11-'144).
7. Remove the fuel line (seepagell-149).
8. Remove the positive crankcase ventilation (PCV)
hose (A), harness holder mounting bolt (B) and
harness clamp mounting bolt (C).
9-4
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9.Remove the engine wire harness connectors and
wire harness clamps from the intake manifold.
. Four injector connectors. ldle air control (lAC) valve connector. Throttle position (TP) sensor connector. fvlanifold absolute pressure {lvlAP) sensor
connector. Evaporative emission (EVAP)canister purge
valve connector
Remove the bolt securing the intake manifold and
bracket.
'1 0.
11.Remove allthe intake manifold mounting bolts/
nuts.
Remove the two stud bolts (A), then remove the
intake manifold (B).
1'>

lntake Manifold and Exhaust System
Intake Manifold Removal and Installation (cont'd)
9. lnstallthe air cleaner housing cover (A), and
connect the IAT sensor connector (B).
BC
Installthe breather hose (C).
lnstallthe EVAP canister hose (A), brake booster
vacuum hose (B), and vacuum hoses {C).
10.
11.
9-6
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12. Installthe intake manifold cover.
6x1.0mm12 N.ml.1.2k91.m,8.7 tbf.ftl
Clean up any spilled engine coolant.
After installation, check that all tubes, hoses, and
connectors are installed correctly.
Inspect for fuel leaks. Turn the ignition switch ON
(ll) (do not operate the starter) so that the fuel pump
runs for about 2 seconds and pressurizes the fuel
line. Repeat this operation two or three times, then
check for fuel leakage at any point in the fuel line.
Refill the radiator with engine coolant, and bleed
air from the cooling system with the heater valve
open (see page 10-6).
to.
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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

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

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.
\

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*
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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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