CO

ENGINE COOLING SYSTEM

Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harness connec-tors. Precautions for Liquid Gasket EBS00DWG REMOVAL OF LIQUID GASKET After removing the mounting bolts and nuts, separate the mating surface using a seal cutter and remove the sealant. CAUTION: Be careful not to damage the mating surfaces.

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B ENGINE

SECTION

ENGINE COOLING SYSTEM C

CONTENTS

QR25DE

WATER PUMP ......................................................... 16 F

Removal and Installation ....................................... 16

PRECAUTIONS ......................................................... 3

REMOVAL .......................................................... 16

Precautions for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT PRE-TEN-

INSPECTION AFTER REMOVAL ...................... 17 G INSTALLATION .................................................. 17

SIONER" ................................................................. 3

INSPECTION AFTER INSTALLATION ............... 17

Precautions for Liquid Gasket ................................. 3 REMOVAL OF LIQUID GASKET ......................... 3

THERMOSTAT AND THERMOSTAT HOUSING ..... 18 Removal and Installation ....................................... 18

LIQUID GASKET APPLICATION PROCEDURE..... 3

REMOVAL .......................................................... 18

PREPARATION .......................................................... 5

INSPECTION AFTER REMOVAL ...................... 19

Special Service Tools .............................................. 5

INSTALLATION .................................................. 19 I

Commercial Service Tools ....................................... 5 WATER CONTROL VALVE ...................................... 20

OVERHEATING CAUSE ANALYSIS ......................... 6

Removal and Installation ....................................... 20

Troubleshooting Chart ............................................. 6

REMOVAL .......................................................... 20 J

COOLING SYSTEM ................................................... 7

INSPECTION AFTER REMOVAL ...................... 21

Cooling Circuit ......................................................... 7

INSTALLATION .................................................. 21

ENGINE COOLANT ................................................... 8 System Check ......................................................... 8

SERVICE DATA AND SPECIFICATIONS (SDS) ..... 22 Capacity ................................................................. 22

CHECKING COOLING SYSTEM HOSES ........... 8

Thermostat ............................................................ 22

CHECKING RESERVOIR LEVEL ........................ 8

Water Control Valve ............................................... 22

CHECKING COOLING SYSTEM FOR LEAKS..... 8

Radiator ................................................................. 22 L

CHECKING RADIATOR CAP ............................... 8

CHECKING RADIATOR ....................................... 9 Refilling Engine Coolant .......................................... 9

VQ35DE
M

RADIATOR ............................................................... 10 PRECAUTIONS ....................................................... 23

Removal and Installation ....................................... 10

Precautions for Supplemental Restraint System

REMOVAL .......................................................... 10

(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-

INSTALLATION .................................................. 10

SIONER" ................................................................ 23

Disassembly and Assembly ...................................11

Precautions for Liquid Gasket ............................... 23

PREPARATION ..................................................11

REMOVAL OF LIQUID GASKET SEALING ....... 23

DISASSEMBLY ...................................................11

LIQUID GASKET APPLICATION PROCEDURE... 23

ASSEMBLY ........................................................ 12 PREPARATION ........................................................ 25

INSPECTION ..................................................... 14

Special Service Tools ............................................ 25

COOLING FAN ........................................................ 15

Commercial Service Tools ..................................... 25

DISASSEMBLY .................................................. 15 OVERHEATING CAUSE ANALYSIS ....................... 26

ASSEMBLY ........................................................ 15

Troubleshooting Chart ........................................... 26

COOLING SYSTEM ................................................. 28

Cooling Circuit ....................................................... 28

Revision: May 2004

CO-1

2003 Altima

ENGINE COOLANT ................................................. 29 System Check ....................................................... 29 CHECKING COOLING SYSTEM HOSES .......... 29 CHECKING RESERVOIR LEVEL ...................... 29 CHECKING COOLING SYSTEM FOR LEAKS ... 29 CHECKING RADIATOR CAP ............................. 29 CHECKING RADIATOR ..................................... 30
RADIATOR ............................................................... 31 Removal and Installation ....................................... 31 REMOVAL .......................................................... 31 INSTALLATION ................................................... 31 Disassembly and Assembly ................................... 32 PREPARATION .................................................. 32 DISASSEMBLY .................................................. 32 ASSEMBLY ........................................................ 33 INSPECTION ...................................................... 35
COOLING FAN ........................................................ 36 DISASSEMBLY .................................................. 36 ASSEMBLY ........................................................ 36

WATER PUMP ..........................................................37 Removal and Installation ........................................37 REMOVAL ...........................................................37 INSPECTION AFTER REMOVAL .......................39 INSTALLATION ...................................................39
THERMOSTAT AND THERMOSTAT HOUSING ......42 Removal and Installation ........................................42 REMOVAL ...........................................................42 INSPECTION AFTER REMOVAL .......................42 INSTALLATION ...................................................43
WATER OUTLET AND WATER PIPING ..................44 Removal and Installation ........................................44 REMOVAL ...........................................................44 INSTALLATION ...................................................44
SERVICE DATA AND SPECIFICATIONS (SDS) .....45 Capacity .................................................................45 Thermostat .............................................................45 Radiator .................................................................45

Revision: May 2004

CO-2

2003 Altima

PRECAUTIONS

[QR25DE]

PRECAUTIONS

PFP:00001

Precautions for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT A

BELT PRE-TENSIONER"

EBS00EZ7

The Supplemental Restraint System such as "AIR BAG" and "SEAT BELT PRE-TENSIONER", used along CO

with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain

types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS

system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted.

Information necessary to service the system safely is included in the SRS and SB section of this Service Man-

ual.

WARNING:

q To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death

in the event of a collision which would result in air bag inflation, all maintenance must be per-

formed by an authorized NISSAN/INFINITI dealer.

q Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-

sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air

Bag Module, see the SRS section.

q Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this

Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harness connec-

tors.

Precautions for Liquid Gasket

EBS00DWG

REMOVAL OF LIQUID GASKET

q After removing the mounting bolts and nuts, separate the mating

surface using a seal cutter and remove the sealant.

CAUTION:

Be careful not to damage the mating surfaces.

q In areas where the cutter is difficult to use, use a plastic hammer to lightly tap the areas where the sealant is applied.

CAUTION: If for some unavoidable reason a tool such as a flat-blade screwdriver is used, be careful not to damage the mating surfaces.

PBIC0002E

LIQUID GASKET APPLICATION PROCEDURE 1. Using a scraper, remove the old sealant adhering to the mating
surfaces.
q Remove the sealant completely from the groove of mating surface, mounting bolts, and bolt holes.
2. Thoroughly clean the sealant mating surface removing all of the adhering moisture, grease and foreign material.
3. Attach the sealant tube to the tube presser. Use Genuine RTV Silicone Sealant or equivalent. Refer to GI-43, "RECOMMENDED CHEMICAL PRODUCTS AND SEALANTS" .

L M
PBIC0003E

Revision: May 2004

CO-3

2003 Altima

PRECAUTIONS
4. Apply the sealant without breaks to the specified location with the specified dimensions.
q If there is a groove for the sealant application, apply the sealant to the groove.
q As for the bolt holes, normally apply the sealant inside the holes. If specified, it should be applied outside the holes. Make sure to read the instructions in this manual.
q Within five minutes of sealant application, install the mating component.
q If the sealant protrudes, wipe it off immediately. q Do not retighten the nuts and bolts after installation. q After 30 minutes or more have passed from the installation, fill
the engine with the proper oil and coolant. Refer to MA-12, "RECOMMENDED FLUIDS AND LUBRICANTS" . CAUTION: If there are instructions in this manual, observe them.

[QR25DE]
EMA0622D SEM159F

Revision: May 2004

CO-4

2003 Altima

PREPARATION

[QR25DE]

PREPARATION Special Service Tools

PFP:00002
A
EBS00DWH

The actual shape of the Kent-Moore tools may differ from those tools illustrated here.

Tool number (Kent-Moore No.) Tool name

Description

WS39930000 ( --- ) Tube presser

Pressing the tube of liquid gasket

EG17650301 (J33984-A) Radiator cap tester adapter
KV99103510 ( --) Radiator plate pliers A

S-NT052 S-NT564

E
Adapting radiator cap tester to radiator filler

neck:

a: 28 (1.10) dia.

b: 31.4 (1.236) dia.

c: 41.3 (1.626) dia.

Unit: mm (in)

Installing radiator upper and lower tanks

KV99103520 ( -- ) Radiator plate pliers B
Commercial Service Tools
Tool name Power tool

S-NT224 S-NT225

I
Removing radiator upper and lower tanks
J

Description Loosening bolts and nuts

EBS00DWI

PBIC0190E

Revision: May 2004

CO-5

2003 Altima

OVERHEATING CAUSE ANALYSIS
OVERHEATING CAUSE ANALYSIS Troubleshooting Chart

[QR25DE]
PFP:00012
EBS00DWJ

Cooling system parts malfunction
Except cooling system parts malfunction

Poor heat transfer

Symptom Water pump malfunction Thermostat stuck closed
Damaged fins

Reduced air flow
Damaged radiator shroud Improper coolant mixture ratio Poor coolant quality

Clogged radiator cooling tube Cooling fan does not operate High resistance to fan rotation Damaged fan blades
--
--
--

Insufficient coolant

Coolant leaks

Overflowing reservoir tank

Overload on engine

Blocked or restricted air flow

Blocked radiator grille Blocked bumper Blocked radiator Blocked condenser Installed large fog lamp

Check items

Worn or loose drive belt

Coolant circulation

Dust contamination or rock

clogging

Mechanical damage

Excess foreign material (rust, dirt, sand, etc.)

Engine cooling fans

-- -- Periodic maintenance Cooling hose Water pump Radiator cap
Radiator
Reservoir tank Exhaust gas leaks into cooling system
Abusive driving
Powertrain system malfunction Installed improper size wheels and tires Dragging brakes Improper ignition timing Installed car brassiere

--
--
-- Loose clamp Cracked hose Poor sealing Loose Poor sealing O-ring for damage, deterioration or improper fitting Cracked radiator tank Cracked radiator core Cracked reservoir tank Cylinder head deterioration Cylinder head gasket deterioration High engine rpm under no load Driving in low gear for extended time Driving at extremely high speed
--

Mud contamination or

paper clogging

Revision: May 2004

CO-6

2003 Altima

COOLING SYSTEM Cooling Circuit

COOLING SYSTEM

[QR25DE]
PFP:21020
A
EBS00DWK
CO
C
D
E
F
G
H
I
WBIA0143E
J
K
L
M

Revision: May 2004

CO-7

PBIC0280E
2003 Altima

ENGINE COOLANT

[QR25DE]

ENGINE COOLANT

PFP:KQ100

System Check

EBS00EZ8

WARNING: Never remove the radiator cap when the engine is hot. Serious burns could occur from high pressure fluid escaping from the radiator. Wrap a thick cloth around the cap. Slowly push down and turn it a quarter turn to allow built-up pressure to escape. Carefully remove the cap by pushing down and turning it all the way.

CHECKING COOLING SYSTEM HOSES Check hoses for the following: q Improper attachment q Leaks q Cracks q Damage q Loose connections q Chafing q Deterioration

CHECKING RESERVOIR LEVEL q Check if the reservoir tank coolant level is within MIN to MAX
when the engine is cool.
q Adjust coolant level if it is too much or too little.

CHECKING COOLING SYSTEM FOR LEAKS To check for leakage, apply pressure to the cooling system with a tester.
Testing pressure : 157 kPa (1.6 kg/cm2 , 23 psi)
WARNING: Never remove the radiator cap when the engine is hot. Serious burns could occur from high pressure coolant escaping from the radiator. CAUTION: Higher pressure than specified may cause radiator damage.
CHECKING RADIATOR CAP 1. Pull the negative pressure valve to open it and check that it
closes completely when released. q Check that there is no dirt or damage on the valve seat of the
radiator cap negative-pressure valve. q Check that there are no abnormalities in the opening and
closing conditions of the negative-pressure valve.

Revision: May 2004

CO-8

SMA412B
SLC756A
SMA967B
2003 Altima

ENGINE COOLANT

[QR25DE]

2. Check radiator cap, apply pressure to cap using Tool.

Radiator cap relief pressure

Standard : 78 - 98 kPa (0.8 - 1.0 kg/cm2 , 11 - 14 psi)

Limit

: 59 kPa (0.6 kg/cm2 , 14 psi)

q When connecting the radiator cap to the Tool, apply water or coolant to the cap seal surface.
q Replace the cap if the there is an abnormality in the negativepressure valve, or if the open-valve pressure is outside of the standard values.
CHECKING RADIATOR

C
SLC755A
D

Check radiator for mud or clogging. If necessary, clean radiator as follows.

q Be careful not to bend or damage the radiator fins.

q When radiator is cleaned without removal, remove all surrounding parts such as cooling fan, radiator

shroud and horns. Then tape the harness and connectors to prevent water from entering.

1. Apply water by hose to the back side of the radiator core vertically downward.

2. Apply water again to all radiator core surfaces once per minute.

3. Stop washing when clear water flows off of the radiator.

4. Blow air into the back side of radiator core vertically downward.

q Use compressed air lower than 490 kPa (5 kg/cm2 , 71 psi) and keep distance more than 300 mm (11.8

in).

5. Blow air again into all the radiator core surfaces once per minute until no water sprays out.

6. Check for leakage.

Refilling Engine Coolant

EBS00EZ9

Changing the engine coolant is part of the required maintenance of the engine. Refer to MA-15, "Changing Engine Coolant" .
J

Revision: May 2004

CO-9

2003 Altima

RADIATOR Removal and Installation

RADIATOR

[QR25DE]
PFP:21400
EBS00T4I

1. Radiator 4. A/T fluid cooler hose (if equipped) 7. Reservoir tank 10. Radiator core connection

2. Radiator upper clip 5. Radiator hose (lower) 8. Radiator hose (upper) 11. Radiator drain plug

3. Mounting rubber 6. Radiator fan assembly 9. Radiator cap

WBIA0282E

WARNING: Never remove the radiator cap when the engine is hot. Serious burns could occur from high pressure coolant escaping from the radiator. Wrap a thick cloth around the cap. Slowly turn it a quarter of a turn to release built-up pressure. Carefully remove radiator cap by turning it all the way.

REMOVAL 1. Drain the coolant from the radiator. Refer to MA-15, "Changing Engine Coolant".
CAUTION: Perform when engine is cold. 2. Remove fresh air duct. Refer to EM-16, "Removal and Installation". 3. Disconnect radiator upper and lower hoses. 4. Remove the A/T fluid cooler hoses, if equipped. q Plug hoses to avoid leakage of A/T fluid. 5. Disconnect the reservoir tank hose.

Revision: May 2004

CO-10

2003 Altima

RADIATOR
6. Remove the radiator upper clips by pulling the tabs outside to release the lock, as shown. CAUTION: To prevent damage, do not pull lock tabs excessively.
7. Remove radiator cooling fan assembly to radiator bolts. 8. Remove the radiator assembly.
CAUTION: Do not damage or scratch air conditioner condenser and radiator core when removing.
INSTALLATION Installation is in the reverse order of removal, paying attention to the following. q Fill the radiator with coolant. Refer to MA-15, "Changing Engine Coolant" .
Installation of Radiator Upper Clip q Install radiator upper clip on radiator core connection with the
following procedure: 1. Install the rubber on mounting pin of radiator core. 2. Align the radiator upper clip with the radiator core connection,
then insert the radiator upper clip straight into the radiator core connections until a click is heard. 3. After connecting the radiator upper clip, use the following method to make sure it is fully connected. q Visually confirm that the two radiator upper clips are con-
nected to the radiator core connections. q Move the radiator upper clip and the radiator forward and
backward to make sure they are securely connected.
Disassembly and Assembly

[QR25DE]
A
CO
C
PBIC1216E
D
E
F
G
H
PBIC1241E
I
EBS00T4J
J
K
L
M

SLC882AB

Revision: May 2004

CO-11

2003 Altima

RADIATOR
PREPARATION 1. Attach the spacer to the tip of the Tool.
Spacer specification: 1.5 mm (0.059 in) thick x 18 mm (0.71 in) wide x 8.5 mm (0.335 in) long. 2. Make sure that when Tool is closed dimension H is approx. 7.6 mm (0.299 in). 3. Adjust dimension H with the spacer, if necessary.
DISASSEMBLY 1. Remove the tank using Tool.
Tool number : KV99103520 ( -- )
q Grip the crimped edge and bend it upwards so that Tool slips off. CAUTION: Do not bend excessively.
q In areas where the Tool cannot be used, use a suitable tool to bend the edge up. CAUTION: Be careful not to damage tank.
2. Remove sealing rubber.
3. Make sure the edge stands straight up, using a suitable tool. 4. Remove oil cooler from tank (if equipped).

Revision: May 2004

CO-12

[QR25DE]
SLC655CB
SLC903-A SLC893 SLC930 SLC931
2003 Altima

RADIATOR
ASSEMBLY 1. Install the oil cooler (if equipped).
NOTE: Pay attention to direction of conical washer.
2. Clean the contact portion of the tank.
3. Install sealing rubber by pushing it in with your fingers. CAUTION: Be careful not to twist sealing rubber gasket.
4. Crimp tank in specified sequence using Tool. Tool number : KV99103510 ( -- )

Revision: May 2004

CO-13

[QR25DE]
A CO
C D
SLC894
E F G
SLC932
H I J K
SLC917A
L M
SLC904-A
SLC896
2003 Altima

RADIATOR
q In the locations where Tool cannot be used use a suitable tool.
5. Make sure that the rim is completely crimped down. Standard height "H" : 8.0 8.4 mm (0.315 0.331 in)
6. Confirm that there is no leakage. Refer to CO-14, "INSPECTION".
INSPECTION 1. Apply pressure using Tool.
Tool number : EG17650301 (J-33984-A) Specified pressure value : 157 kPa (1.6 kg/cm2 , 23
psi) WARNING: To prevent the risk of the hose coming undone while under pressure, securely fasten it down with a hose clamp. CAUTION: Attach a hose to the oil cooler as well (if equipped). 2. Place radiator in water filled tank and check for leakage.

Revision: May 2004

CO-14

[QR25DE]
SLC897 SLC554A SLC933-A SLC934
2003 Altima

COOLING FAN

[QR25DE]

COOLING FAN Removal and Installation

PFP:21140
A
EBS00T4K

WARNING: Never remove the radiator cap when the engine is hot. Serious burns could occur form high pressure CO coolant escaping from the radiator

REMOVAL

1. Drain engine coolant from radiator. Refer to MA-15, "Changing Engine Coolant".

CAUTION: Perform when engine is cold.

2. Remove air cleaner duct assembly. Refer to EM-16, "Removal and Installation".

3. Disconnect radiator upper hose.

4. Disconnect fan motor connectors.

5. Remove radiator cooling fan assembly.

INSTALLATION

Install in the reverse order of removal.

q Cooling fan is controlled by ECM. For details, refer to EC-435, "DTC P1217 ENGINE OVER TEMPERATURE".

Disassembly and Assembly of Radiator Fan

G
EBS00T4L

1. Fan blade

2. Fan shroud

DISASSEMBLY 1. Remove fan blade. 2. Remove fan motor from fan shroud.

ASSEMBLY Assembly is in the reverse order of disassembly.

Revision: May 2004

CO-15

3. Fan motor

WBIA0362E

2003 Altima

WATER PUMP Removal and Installation

WATER PUMP

[QR25DE]
PFP:21020
EBS00DWR

KBIA0154E

1. Water pump 4. Water pipe

2. Gasket

3. Water pump housing

WARNING: Never remove the radiator cap when the engine is hot. Serious burns could occur from high pressure coolant escaping from the radiator.

REMOVAL 1. Drain coolant. Refer to MA-15, "Changing Engine Coolant" .
CAUTION: Perform when the engine is cold. 2. Remove the following parts: q Undercover, using power tools. q Alternator, water pump and air compressor drive belt. q Engine cover and coolant reservoir. q IPDM E/R (set aside). Refer to PG-24, "Removal and Installation of IPDM E/R" . q Front passenger side wheel and tire, and splash shield. q Engine ground. 3. Remove the water pump. NOTE: If necessary, the alternator and exhaust manifold catalytic convertor assembly must be removed to remove the water pipe. CAUTION: q Handle the water pump vane so that it does not contact any other parts. q Water pump cannot be disassembled and should be replaced as an assembly.

Revision: May 2004

CO-16

2003 Altima

WATER PUMP
INSPECTION AFTER REMOVAL q Visually check that there is no significant dirt or rusting on the
water pump body and vane. q Check that there is no looseness in the vane shaft, and that it
turns smoothly when rotated by hand. q If the water pump does not perform properly, replace the water
pump assembly.

[QR25DE]
A CO
C

D
KBIA0155E

INSTALLATION

q Installation is in the reverse order of removal.

q When inserting water pipe end to cylinder block, apply a neutral detergent to O-ring. Then insert it imme-

diately.

INSPECTION AFTER INSTALLATION

q After installing the water pump, check for leaks using the radiator cap tester. Refer to CO-14, "INSPECTION" .

Revision: May 2004

CO-17

2003 Altima

THERMOSTAT AND THERMOSTAT HOUSING
THERMOSTAT AND THERMOSTAT HOUSING Removal and Installation

[QR25DE]
PFP:21200
EBS00DWS

WBIA0010E

1. Thermostat 4. Engine coolant outlet 7. Heater pipe

2. Engine coolant inlet

3. Water control valve

5. Heater hose

6. Engine coolant temperature sensor

8. Electric throttle control actuator inlet 9. Electric throttle control actuator out-

hose

let hose

WARNING: Never remove the radiator cap when the engine is hot. Serious burns could occur from high pressure coolant escaping from the radiator.

REMOVAL CAUTION: Perform when the engine is cold. 1. Drain engine coolant. Refer to MA-15, "Changing Engine Coolant" . 2. Remove radiator lower hose from the engine coolant inlet side. 3. Remove engine coolant inlet and thermostat.

Revision: May 2004

CO-18

2003 Altima

THERMOSTAT AND THERMOSTAT HOUSING

[QR25DE]

INSPECTION AFTER REMOVAL
q Place a thread so that it is caught in the valves of the thermostat. Immerse fully in a container filled with water. Heat while stirring.
q The valve opening temperature is the temperature at which the valve opens and the falls from the thread.
q Continue heating. Check the full-open lift amount.
NOTE: The full-open lift amount standard temperature for the thermostat is the reference value.
q After checking the full-open lift amount, lower the water temperature and check the valve closing temperature.

A CO
C D
SLC252B

Thermostat

Standard Values

Valve opening temperature Valve lift

80.5 83.5°C (177 182°F)

More than 8 mm / 95°C (0.315 in / 203°F)

Valve closing temperature

77°C (171°F) or higher

INSTALLATION

Installation is in the reverse order of removal.

Install the engine coolant temperature sensor. Use Genuine RTV Silicone Sealant or equivalent. Refer to GI-43, "RECOMMENDED CHEMICAL

PRODUCTS AND SEALANTS" .

q Install the thermostat with the whole circumference of the flange

part fitting securely inside the rubber ring.

q Install the thermostat with the jiggle valve facing upwards. The

position deviation may be within the range of ±10°.

q If necessary, to install the heater pipe, first apply a mild deter-

gent to the O-ring and then quickly insert the pipe into the hous-

ing.

PBIC0157E

Revision: May 2004

CO-19

2003 Altima

WATER CONTROL VALVE
WATER CONTROL VALVE Removal and Installation

[QR25DE]
PFP:21230
EBS00DWT

WBIA0010E

1. Thermostat 4. Engine coolant outlet 7. Heater pipe

2. Engine coolant inlet

3. Water control valve

5. Heater hose

6. Engine coolant temperature sensor

8. Electric throttle control actuator inlet 9. Electric throttle control actuator out-

hose

let hose

WARNING: Never remove the radiator cap when the engine is hot. Serious burns could occur from high pressure coolant escaping from the radiator.

REMOVAL CAUTION: Perform when the engine cold. 1. Drain the engine coolant. Refer to MA-15, "Changing Engine Coolant" . 2. Remove the upper radiator hose, heater pipe, electric throttle control actuator inlet hose, and heater hose. 3. Remove the engine coolant outlet. 4. Remove the water control valve.

Revision: May 2004

CO-20

2003 Altima

WATER CONTROL VALVE

[QR25DE]

INSPECTION AFTER REMOVAL
q Place a thread so that it is caught in the valve of the water control valve. Immerse fully in a container filled with water. Heat while stirring.
q The valve opening temperature is the temperature at which the valve opens and the falls from the thread.
q Continue heating. Check the full-open lift amount.
NOTE: The full-open lift amount standard temperature for the water control valve is the reference value.
q After checking the full-open lift amount, lower the water temperature and check the valve closing temperature.

A CO
C D
SLC252B

Standard values

Water Control Valve

Standard Value

Valve opening temperature

93.5° - 96.5°C (200° - 206°F)

Full-open lift amount Valve closing temperature

More than 8 mm / 108°C (0.315 in / 226° F)

90°C (194° F) or higher

INSTALLATION

Installation is in the reverse order of removal.

q Install the engine coolant temperature sensor.

Use Genuine RTV Silicone Sealant or equivalent. Refer to GI-43, "RECOMMENDED CHEMICAL

PRODUCTS AND SEALANTS" .

q Install the water control valve with the whole circumference of the flange part fitting securely inside the
rubber ring. q Install the water control valve with the up-mark facing up and the frame center part facing upwards. The I
position deviation may be within the range of ±10°.

Revision: May 2004

CO-21

2003 Altima

SERVICE DATA AND SPECIFICATIONS (SDS)
SERVICE DATA AND SPECIFICATIONS (SDS) Capacity

[QR25DE]
PFP:00030
EBS00DWU

Coolant capacity (With reservoir tank at MAX level) Reservoir tank coolant capacity (at MAX level)
Thermostat

6.9 (7 1/4 qt.) 0.7 (3/4 qt.)

EBS00DWV

Valve opening temperature Valve lift
Water Control Valve

80.5 - 83.5°C (177 - 182°F) More than 8 mm / 95°C (0.315 in / 203°F)

EBS00DWW

Valve opening temperature Valve lift
Radiator
Cap relief pressure Leakage test pressure

Standard Limit

93.5-96.5°C (200-206°F) More than 8 mm / 108°C (0.315 in / 226°F)
EBS00DWX
Unit: kPa (kg / cm2 , psi) 78 - 98 (0.8 - 1.0, 11 - 14)
59 (0.6, 9) 157 (1.6, 23)

Revision: May 2004

CO-22

2003 Altima

PRECAUTIONS

[VQ35DE]

PRECAUTIONS

PFP:00001

Precautions for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT A

BELT PRE-TENSIONER"

EBS00EZA

The Supplemental Restraint System such as "AIR BAG" and "SEAT BELT PRE-TENSIONER", used along CO

with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain

types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS

Information necessary to service the system safely is included in the SRS and SB section of this Service Man-

ual.

WARNING:

q To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death

in the event of a collision which would result in air bag inflation, all maintenance must be per-

formed by an authorized NISSAN/INFINITI dealer.

q Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-

sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air

Bag Module, see the SRS section.

q Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this

Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harness connec-

tors.

Precautions for Liquid Gasket

EBS00DWZ

REMOVAL OF LIQUID GASKET SEALING

q After removing the mounting bolts and nuts, separate the mating

surface using a seal cutter and remove the sealant.

CAUTION:

Be careful not to damage the mating surfaces.

q In areas where the cutter is difficult to use, use a plastic hammer to lightly tap the area where the sealant is applied.

CAUTION: If for some unavoidable reason a tool such as a flat-bladed screwdriver is used, be careful not to damage the mating surfaces.

PBIC0002E

LIQUID GASKET APPLICATION PROCEDURE 1. Using a scraper, remove the old sealant adhering to the mating
surfaces.
q Remove the sealant completely from the groove of the mating surfaces, mounting bolts, and bolt holes.
2. Thoroughly clean the mating surfaces and remove all adhering moisture, grease and foreign material.
3. Attach the sealant tube to the tube presser. Use Genuine RTV Silicone Sealant or equivalent. Refer to GI-43, "RECOMMENDED CHEMICAL PRODUCTS AND SEALANTS" .

L M
PBIC0003E

Revision: May 2004

CO-23

2003 Altima

PRECAUTIONS
4. Apply the sealant without breaks to the specified location with the specified dimensions.
q If there is a groove for the sealant application, apply the sealant to the groove.
q As for the bolt holes, normally apply the sealant inside the holes. If specified in the procedure, it should also be applied outside the holes.
q Within five minutes of sealant application, install the mating component.
q If the sealant protrudes, wipe it off immediately. q Do not retighten after the installation. q After 30 minutes or more have passed from the installation, fill
the engine with the specified oil and coolant. Refer to MA-12, "RECOMMENDED FLUIDS AND LUBRICANTS" .

[VQ35DE]
EMA0622D SEM159F

Revision: May 2004

CO-24

2003 Altima

PREPARATION

[VQ35DE]

PREPARATION

Special Service Tools

The actual shapes of Kent-Moore tools may from those of special service tools illustrated here.

Tool number (Kent-Moore No.) Tool name

Description

PFP:00002
A
EBS00DX0
CO

WS39930000

(

)

Tube pressure

Pressing the tube of liquid gasket
C

EG17650301 (J33984-A) Radiator cap tester adapter

KV99103510

(

)

Radiator plate pliers A

S-NT052 S-NT564

Adapting radiator cap tester to radiator cap

and radiator filler neck

a: 28 (1.10) dia.

b: 31.4 (1.236) dia.

c: 41.3 (1.626) dia.

Unit: mm (in)

G
Installing radiator upper and lower tanks

KV99103520

(

)

Radiator plate pliers B

S-NT224

I
Removing radiator upper and lower tanks
J

Commercial Service Tools
Tool name Power tool

S-NT225

Description Loosening bolts and nuts

EBS00DX1

PBIC0190E

Revision: May 2004

CO-25

2003 Altima

OVERHEATING CAUSE ANALYSIS
OVERHEATING CAUSE ANALYSIS Troubleshooting Chart

[VQ35DE]
PFP:00012
EBS00DX2

Cooling system parts malfunction

Poor heat transfer

Symptom Water pump malfunction Thermostat stuck closed
Damaged fins

Reduced air flow
Damaged radiator shroud Improper coolant mixture ratio Poor coolant quality

Clogged radiator cooling tube Cooling fan does not operate High resistance to fan rotation Damaged fan blades
--
--
--

Insufficient coolant

Coolant leaks

Overflowing reservoir tank

Check items

Worn or loose drive belt

Dust contamination or

paper clogging

Physical damage

Excess foreign material (rust, dirt, sand, etc.)

Fan assembly

-- -- Coolant viscosity Cooling hose Water pump Radiator cap
Radiator
Reservoir tank Exhaust gas leaks into cooling system

Revision: May 2004

CO-26

2003 Altima

OVERHEATING CAUSE ANALYSIS

[VQ35DE]

Symptom

Overload on engine

Except cooling system parts malfunction
Blocked or restricted air flow

Blocked bumper
Blocked radiator grille
Blocked radiator Blocked condenser Installed large fog lamp

Check items
A
High engine rpm under no
load

Abusive driving

Driving in low gear for

extended time

Driving at extremely high

speed

Powertrain system mal-

function

Installed improper size wheels and tires

Dragging brakes

Improper ignition timing
E
--

Installed car brassiere

Mud contamination or paper clogging
--

F
--

G
Blocked air flow

Revision: May 2004

CO-27

2003 Altima

COOLING SYSTEM Cooling Circuit

COOLING SYSTEM

[VQ35DE]
PFP:21020
EBS00DX3

WBIA0144E

Revision: May 2004

CO-28

2003 Altima

ENGINE COOLANT

[VQ35DE]

ENGINE COOLANT System Check

PFP:KQ100
A
EBS00EZB

WARNING:
Never remove the radiator cap when the engine is hot. Serious burns could occur from high pressure CO fluid escaping from the radiator.
Wrap a thick cloth around the cap. Slowly push down and turn it a quarter turn to allow built-up pres-
sure to escape. Carefully remove the cap by pushing down and turning it all the way. C
CHECKING COOLING SYSTEM HOSES

Check hoses for the following:

q Improper attachment

q Leaks

q Cracks

q Damage

q Loose connections

q Chafing F
q Deterioration

CHECKING RESERVOIR LEVEL

q Check if the reservoir tank coolant level is within MIN to MAX

when the engine is cool.

q Adjust coolant level if it is too much or too little.

SMA412B

SLC756A

Revision: May 2004

CO-29

SMA967B
2003 Altima

ENGINE COOLANT

2. Check radiator cap, apply pressure to cap using Tool.

Radiator cap relief pressure

Standard : 78 - 98 kPa (0.8 - 1.0 kg/cm2 , 11 - 14 psi)

Limit

: 59 kPa (0.6 kg/cm

[VQ35DE]

SLC755A
CHECKING RADIATOR Check radiator for mud or clogging. If necessary, clean radiator as follows. q Be careful not to bend or damage the radiator fins. q When radiator is cleaned without removal, remove all surrounding parts such as cooling fan, radiator
shroud and horns. Then tape the harness and connectors to prevent water from entering. 1. Apply water by hose to the back side of the radiator core vertically downward. 2. Apply water again to all radiator core surfaces once per minute. 3. Stop washing when clear water flows off of the radiator. 4. Blow air into the back side of radiator core vertically downward.
q Use compressed air lower than 490 kPa (5 kg/cm2 , 71 psi) and keep distance more than 300 mm (11.8 in).
5. Blow air again into all the radiator core surfaces once per minute until no water sprays out. 6. Check for leakage.

Revision: May 2004

CO-30

2003 Altima

RADIATOR Removal and Installation

RADIATOR

[VQ35DE]
PFP:21400
A
EBS00T4Q
CO

1. Radiator 4. A/T fluid cooler hose (if equipped) 7. Reservoir tank 10. Radiator core connection

2. Radiator upper clip 5. Radiator hose (lower) 8. Radiator hose (upper) 11. Radiator drain plug

3. Mounting rubber

WBIA0282E
J

6. Radiator fan assembly

9. Radiator cap
K

WARNING: Never remove the radiator cap when the engine is hot. Serious burns could occur from high pressure coolant escaping from the radiator. Wrap a thick cloth around the cap. Slowly turn it a quarter of a turn L to release built-up pressure. Carefully remove radiator cap by turning it all the way.

REMOVAL

1. Drain the coolant from the radiator. Refer to MA-23, "Changing Engine Coolant".

CAUTION: Perform when engine is cold.

2. Remove fresh air duct. Refer to EM-119, "Removal and Installation".

3. Disconnect radiator upper and lower hoses.

4. Remove the A/T fluid cooler hoses, if equipped.

q Plug hoses to avoid leakage of A/T fluid.

5. Disconnect the reservoir tank hose.

Revision: May 2004

CO-31

2003 Altima

RADIATOR
6. Remove the radiator upper clips by pulling the tabs outside to release the lock, as shown. CAUTION: To prevent damage, do not pull lock tabs excessively.
7. Remove radiator cooling fan assembly to radiator bolts. 8. Remove the radiator assembly.
CAUTION: Do not damage or scratch air conditioner condenser and radiator core when removing.
INSTALLATION Installation is in the reverse order of removal, paying attention to the following. q Fill the radiator with coolant. Refer to MA-23, "Changing Engine Coolant".
Installation of Radiator Upper Clip q Install radiator upper clip on radiator core connection with the
following procedure: 1. Install the rubber on mounting pin of radiator core. 2. Align the radiator upper clip with the radiator core connection,
then insert the radiator upper clip straight into the radiator core connections until a click is heard. 3. After connecting the radiator upper clip, use the following method to make sure it is fully connected. q Visually confirm that the two radiator upper clips are con-
nected to the radiator core connections. q Move the radiator upper clip and the radiator forward and
backward to make sure they are securely connected.
Disassembly and Assembly

[VQ35DE]
PBIC1216E
PBIC1241E EBS00T4R

Revision: May 2004

CO-32

SLC882AB
2003 Altima

Revision: May 2004

CO-33

[VQ35DE]
A

D
SLC655CB
E

SLC903-A

K
SLC893
L

SLC930

SLC931
2003 Altima

Revision: May 2004

CO-34

[VQ35DE]
SLC894 SLC932 SLC917A SLC904-A SLC896
2003 Altima

RADIATOR
q In the locations where Tool cannot be used use a suitable tool.
5. Make sure that the rim is completely crimped down. Standard height "H" : 8.0 8.4 mm (0.315 0.331 in)
6. Confirm that there is no leakage. Refer to CO-35, "INSPECTION".
INSPECTION 1. Apply pressure using Tool.
Tool number : EG17650301 (J-33984-A) Specified pressure value : 157 kPa (1.6 kg/cm2 , 23
psi) WARNING: To prevent the risk of the hose coming undone while under pressure, securely fasten it down with a hose clamp. CAUTION: Attach a hose to the oil cooler as well (if equipped). 2. Place radiator in water filled tank and check for leakage.

[VQ35DE]
A CO
C
SLC897
D E F G
SLC554A
H I J K
SLC933-A
L M
SLC934

Revision: May 2004

CO-35

2003 Altima

COOLING FAN

[VQ35DE]

COOLING FAN

PFP:21140

Removal and Installation

EBS00T4S

WARNING: Never remove the radiator cap when the engine is hot. Serious burns could occur form high pressure coolant escaping from the radiator

REMOVAL 1. Drain engine coolant from radiator. Refer to MA-23, "Changing Engine Coolant".
CAUTION: Perform when engine is cold. 2. Remove air cleaner duct assembly. Refer to EM-119, "Removal and Installation". 3. Disconnect radiator upper hose. 4. Disconnect fan motor connectors. 5. Remove radiator cooling fan assembly.

INSTALLATION Install in the reverse order of removal.
q Cooling fan is controlled by ECM. For details, refer to EC-1104, "DTC P1217 ENGINE OVER TEMPERATURE".

Disassembly and Assembly of Radiator Fan

EBS00T4T

1. Fan blade

2. Fan shroud

DISASSEMBLY 1. Remove fan blade. 2. Remove fan motor from fan shroud.

ASSEMBLY Assembly is in the reverse order of disassembly.

Revision: May 2004

CO-36

3. Fan motor

WBIA0362E

2003 Altima

WATER PUMP Removal and Installation

WATER PUMP

[VQ35DE]
PFP:21020
A
EBS00DX9
CO

G
WBIA0067E

CAUTION:

q When removing water pump assembly, be careful not to get coolant on drive belt.

q Water pump cannot be disassembled and should be replaced as a unit.

q After installing water pump, connect hose and clamp securely, then check for leaks using radiator cap tester. I
REMOVAL

1. Remove undercover, using power tools.

2. Drain coolant from radiator. Refer to MA-23, "Changing Engine Coolant" .

CAUTION:

Perform when the engine is cold.

3. Remove engine coolant reservoir tank. Refer to CO-31, "Removal and Installation" .

4. Reposition IPDM/ER aside. Refer to PG-24, "Removal and Installation of IPDM E/R" .

5. Remove RH wheel and tire and the splash shield.

6. Remove drive belts.

7. Remove idler pulley, then the power steering and generator adjusting bars.

8. Support engine and remove the front engine insulator and bracket. Refer to EM-202, "Removal and Instal-

lation" .

9. Remove water drain plug on water pump side of cylinder block.

10. Remove chain tensioner cover and water pump cover.

11. Remove the chain tensioner assembly.

a. Pull the lever down and release the plunger stopper tab.

PBIC0846E

Revision: May 2004

CO-37

2003 Altima

WATER PUMP
b. Insert the stopper pin into the tensioner body hole to hold the lever and keep the stopper tab released. NOTE: An allen wrench [(2.5 mm (0.98 in)] is used for a stopper pin as an example.

[VQ35DE]

SLC444B
c. Insert the plunger into the tensioner body by pressing the timing chain slack guide. d. Keep the slack guide pressed and hold the plunger in by pushing the stopper pin deeper through the lever
and into the tensioner body hole e. Make a gap between water pump gear and timing chain, by turn-
ing the crankshaft pulley approximately 20° clockwise.

12. Remove chain tensioner. CAUTION: Be careful not to drop mounting bolts inside chain case.
13. Remove the three water pump mounting bolts. Make a gap between water pump gear and timing chain, by turning crankshaft pulley counterclockwise until timing chain loosens on water pump sprocket.

PBIC0848E PBIC0849E PBIC0850E

Revision: May 2004

CO-38

2003 Altima

WATER PUMP
14. Screw M8 bolts [pitch: 1.25 mm (0.49 in) length: approx. 50 mm (1.97 in)] into water pumps upper and lower mounting bolt holes until they reach the timing chain case. Then, alternately tighten each bolt for a half turn, and pull out the water pump. q Pull straight out while preventing vane from contacting socket in installation area. q Remove water pump without causing sprocket to contact timing chain.
15. Remove M8 bolts and O-rings from water pump.
INSPECTION AFTER REMOVAL 1. Check for badly rusted or corroded water pump body assembly. 2. Check for rough operation due to excessive end play.

[VQ35DE]
A
CO
C
JLC357B
D
E

INSTALLATION 1. Install new O-rings to water pump. 2. Apply engine oil and coolant to the O-rings as shown.
q Locate the O-ring with white paint mark to engine front side.

G
SLC943A
H
I
J

3. Install the water pump.
CAUTION: Do not allow cylinder block to interfere with the O-rings when installing the water pump.
q Check that timing chain and water pump sprocket are engaged.
q Insert water pump by tightening mounting bolts alternately and evenly.

Water pump mounting bolts

8.5 10.7 N·m (0.86 1.10 kg-m, 75 95 in-lb)

PBIC0855E
L M
SLC031B

4. Remove dust and foreign material completely from backside of chain tensioner and from installation area of rear timing chain case.

Revision: May 2004

CO-39

2003 Altima

WATER PUMP
5. Turn the crankshaft pulley approximately 20° clockwise so that the timing chain on the timing chain tensioner side is loose. NOTE: When installing the timing chain tensioner, engine oil should be applied to the oil hole and tensioner.

6. Install the timing chain tensioner.

Timing chain tensioner 7.0 9.3 N·m (0.71 0.95 kg-m,

mounting bolts

62 82 in-lb)

7. Remove the stopper pin.

[VQ35DE]
PBIC0848E

8. Install chain tensioner and water pump cover. a. Before installing, remove all traces of sealant from mating sur-
face of water pump cover and chain tensioner cover using a scraper. Also remove traces of sealant from the mating surface of the front cover.
b. Apply a continuous bead of RTV Silicone Sealant or equivalent, to mating surface of chain tensioner cover and water pump cover. Refer to GI-43, "RECOMMENDED CHEMICAL PRODUCTS AND SEALANTS" .

SLC448B SLC446B

SLC447B

9. Install water drain plug on water pump side of cylinder block. Refer to MA-23, "Changing Engine Coolant" .
10. Install idler pulley.

Idler pulley bolts : 25 - 31 N·m (2.5 - 3.2 kg-m, 18 - 23 ft-lb)

11. Installation of remaining components is in the reverse order of removal.

Revision: May 2004

CO-40

2003 Altima

WATER PUMP

[VQ35DE]

q Refill engine coolant. Refer to MA-23, "REFILLING ENGINE COOLANT" . q After starting engine, let idle for three minutes, then rev engine up to 3,000 rpm under no load to purge A
air from the high-pressure chamber of the chain tensioner. The engine may produce a rattling noise. This indicates that air still remains in the chamber and is not a matter of concern.
CO

Revision: May 2004

CO-41

2003 Altima

THERMOSTAT AND THERMOSTAT HOUSING
THERMOSTAT AND THERMOSTAT HOUSING Removal and Installation

[VQ35DE]
PFP:21200
EBS00DXA

REMOVAL 1. Remove undercover using power tool. 2. Drain coolant from radiator. Refer to MA-23, "Changing Engine Coolant" .
CAUTION: Perform when engine is cool. 3. Remove drive belts. 4. Remove water drain plug on water pump side of the engine. 5. Disconnect lower radiator hose. 6. Remove engine coolant inlet and thermostat assembly. q Do not disassemble engine coolant inlet and thermostat.
Replace them as a unit, if necessary.

WBIA0068E

INSPECTION AFTER REMOVAL 1. Check valve seating condition at ordinary room temperatures. It should seat tightly. 2. Check valve opening temperature and maximum valve lift.

Thermostat

Standard Values

Valve opening temperature

82°C (180°F)

Valve lift

8.6 mm / 95°C (0.339 in / 203°F)

3. Then check if valve closes at 5°C (9°F) below valve opening temperature.

Revision: May 2004

CO-42

SLC962AA
SLC949A
2003 Altima

THERMOSTAT AND THERMOSTAT HOUSING
INSTALLATION 1. Install thermostat with jiggle valve facing upward.
q After installation, run engine for a few minutes, and check for leaks.
q Be careful not to spill coolant over engine compartment. Use a rag to absorb coolant.
2. Installation is in the reverse order of removal.

[VQ35DE]
A CO
C D
SLC948A
E F G H I J K L M

Revision: May 2004

CO-43

2003 Altima

WATER OUTLET AND WATER PIPING
WATER OUTLET AND WATER PIPING Removal and Installation

[VQ35DE]
PFP:11060
EBS00GJI

1. Water outlet

2. Gasket

4. Heater pipe

5. Water connector

7. Engine coolant temperature sensor 8. Washer

3. O-ring 6. Water bypass pipe

WBIA0281E

REMOVAL 1. Remove undercover. 2. Drain coolant from drain plugs on radiator and both sides of cylinder block. Refer to MA-23, "DRAINING
ENGINE COOLANT" . CAUTION: Perform when the engine is cold. 3. Remove engine cover using power tool. 4. Remove air duct and air cleaner case assembly. Refer to EM-119, "Removal and Installation" . 5. Remove radiator upper hose and heater hose. 6. Remove connector(s) from heater pipe. 7. Disconnect engine coolant temperature sensor electrical connector on water outlet. 8. Remove water outlet, heater pipe, water connector, and water bypass pipe mounting nuts and bolts.
INSTALLATION 1. Install in the reverse order of removal.
q Securely insert each hose, and install a clamp at a position where it does not interfere with the pipe bulge.
q When inserting a water pipe into water connector, apply neutral detergent to O-ring. q Refill engine coolant. Refer to MA-23, "REFILLING ENGINE COOLANT" .

Revision: May 2004

CO-44

2003 Altima

SERVICE DATA AND SPECIFICATIONS (SDS)
SERVICE DATA AND SPECIFICATIONS (SDS) Capacity

[VQ35DE]
PFP:00100
A
EBS00DXB

Coolant capacity (With reservoir tank at MAX level) Reservoir tank coolant capacity (at MAX level)
Thermostat
Valve opening temperature Valve lift
Radiator

Cap relief pressure Leakage test pressure

Standard Limit

7.5 (7 7/8 qt.)
CO
0.7 (3/4 qt.)

82°C (180°F)

EBS00DXC
C

8.6 mm / 95°C (0.339 in / 203°F)

D
EBS00DXD
Unit: kPa (kg/cm2 , psi)

78 98 (0.8 1.0, 11 14)

59 (0.6, 9)

157 (1.6, 23)
F

Revision: May 2004

CO-45

2003 Altima

SERVICE DATA AND SPECIFICATIONS (SDS)

[VQ35DE]

Revision: May 2004

CO-46

2003 Altima

Acrobat Distiller 4.05 for Windows FrameMaker SGML 5.5.6p145