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Nissan Pathfinder (2010 year). Manual - part 126

CO-6

< PREPARATION >

[VQ40DE]

PREPARATION

Tool name

Description

Power tool

Loosening bolts and nuts

Radiator cap tester

Checking radiator and radiator cap

Coolant system tester adapter

Adapting radiator cap tester to reservoir filler
neck

Coolant system tester adapter

Adapting radiator cap tester to reservoir cap

PBIC0190E

PBIC1982E

WBIA0408E

WBIA0409E

2010 Pathfinder

COOLING SYSTEM

CO-7

< FUNCTION DIAGNOSIS >

[VQ40DE]

FUNCTION DIAGNOSIS

COOLING SYSTEM

Cooling Circuit

INFOID:0000000005260553

WBIA0641E

Cylinder block (RH)

Oil cooler

Cylinder head (RH)

Water pump

Radiator

Water inlet

Thermostat

Cylinder head (LH)

Heater pump

10. Cylinder block (LH)

2010 Pathfinder

CO-8

< FUNCTION DIAGNOSIS >

[VQ40DE]

COOLING SYSTEM

Schematic

INFOID:0000000005260554

WBIA0565E

2010 Pathfinder

OVERHEATING CAUSE ANALYSIS

CO-9

< FUNCTION DIAGNOSIS >

[VQ40DE]

OVERHEATING CAUSE ANALYSIS

Troubleshooting Chart

INFOID:0000000005260555

Symptom

Check items

Cooling sys-
tem parts
malfunction

Poor heat transfer

Water pump malfunction

Worn or loose drive belt

—

Thermostat stuck closed

—

Damaged fins

Dust contamination or pa-
per clogging

Physical damage

Clogged radiator cooling
tube

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

Reduced air flow

Cooling fan does not oper-
ate

Fan assembly

—

High resistance to fan rota-
tion

Damaged fan blades

Damaged radiator shroud

—

Improper engine coolant
mixture ratio

—

Poor engine coolant quality

—

Engine coolant viscosity

—

Insufficient engine coolant

Engine coolant leaks

Cooling hose

Loose clamp

Cracked hose

Heater pump

Physical damage

Water pump

Poor sealing

Radiator cap

Loose

Poor sealing

Radiator

O-ring for damage, deterio-
ration or improper fitting

Cracked radiator tank

Cracked radiator core

Reservoir tank

Cracked reservoir tank

Overflowing reservoir tank

Exhaust gas leaks into cool-
ing system

Cylinder head deterioration

Cylinder head gasket deteri-
oration

2010 Pathfinder

CO-10

< FUNCTION DIAGNOSIS >

[VQ40DE]

OVERHEATING CAUSE ANALYSIS

Except cool-
ing system
parts mal-
function

—

Overload on engine

Abusive driving

High engine rpm under no
load

Driving in low gear for ex-
tended time

Driving at extremely high
speed

Powertrain system malfunc-
tion

—

Installed improper size
wheels and tires

Dragging brakes

Improper ignition timing

Blocked or restricted air
flow

Blocked bumper

—

Blocked radiator grille

Installed car brassiere

Mud contamination or paper
clogging

Blocked radiator

—

Blocked condenser

Blocked air flow

Installed large fog lamp

Symptom

Check items

2010 Pathfinder

ENGINE COOLANT

CO-11

< ON-VEHICLE MAINTENANCE >

[VQ40DE]

ON-VEHICLE MAINTENANCE

ENGINE COOLANT

System Inspection

INFOID:0000000005260556

WARNING:

• Never remove the radiator/reservoir cap when the engine is hot. Serious burns could occur from

high pressure fluid escaping from the radiator or reservoir.

• 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.

CHECKING COOLING SYSTEM HOSES

Check hoses for the following:

• Improper attachment

• Leaks

• Cracks

• Damage

• Loose connections

• Chafing

• Deterioration

CHECKING RESERVOIR LEVEL

• Check if the engine coolant reservoir tank level is within MIN to

MAX when the engine is cool.

• Adjust engine coolant level as necessary.

CHECKING COOLING SYSTEM FOR LEAKS

WARNING:

Never remove the radiator/reservoir cap when the engine is hot. Serious burns could occur from high

pressure coolant escaping from the radiator or reservoir.

• To check for leakage, apply pressure to the cooling system at the

reservoir filler neck using suitable tool and Tool.

CAUTION:

Higher pressure than specified may cause radiator damage.

NOTE:

In case that engine coolant decreases, replenish cooling system

with engine coolant.

• If any concerns are found, repair or replace damaged parts.

CHECKING RESERVOIR CAP

SMA412B

Tool number

: EG17650301 (J-33984-A)

Testing pressure : 137 kPa (1.4 kg/cm

, 20 psi)

WBIA0568E

2010 Pathfinder

CO-12

< ON-VEHICLE MAINTENANCE >

[VQ40DE]

ENGINE COOLANT

• Check reservoir cap relief pressure using suitable tool and Tool.

NOTE:

Apply engine coolant to the cap seal.

• Replace the reservoir cap if there is any damage in the negative-

pressure valve, or if the open-valve pressure is outside of the limit.

CHECKING RADIATOR CAP

Inspect the radiator cap.

NOTE:

Thoroughly wipe out the radiator filler neck to remove any waxy residue or foreign material.

• Replace the cap if the metal plunger cannot be seen around the edge of the black rubber gasket.

• Replace the cap if deposits of waxy residue or other foreign material are on the black rubber gasket or the

metal retainer.

CHECKING RADIATOR

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

CAUTION:

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

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

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

1. Apply water by hose to the back side of the radiator core, with the hose pointed vertically downward.
2. Apply water again to all radiator core surfaces once per minute.
3. Stop washing if any stains no longer flow out from the radiator.
4. Blow air into the back side of radiator core, with the air hose pointed vertically downward.

• Use compressed air lower than 490 kPa (5 kg/cm

, 71 psi) and keep distance more than 30 cm (11.8 in).

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

Changing Engine Coolant

INFOID:0000000005260557

WARNING:

• To avoid being scalded, never change the coolant when the engine is hot.

• Wrap a thick cloth around the cap to carefully remove the cap. First, turn the cap a quarter of a turn

to release any built-up pressure, then push down and turn the cap all the way to remove it.

DRAINING ENGINE COOLANT

1. Turn ignition switch ON and set temperature control lever all the way to HOT position or the highest tem-

perature position. Wait 10 seconds and turn ignition switch OFF.

2. Remove the engine front undercover using power tool.
3. Open the radiator drain plug at the bottom of the radiator, and

remove the reservoir cap. This is the only step required when

partially draining the cooling system (radiator only).

CAUTION:

Do not allow the coolant to contact the drive belts.

Tool number

: EG17650301 (J-33984-A)

Standard: 98 – 118 kPa (1.0 – 1.2 kg/cm

, 14 – 17 psi)

WBIA0570E

LLIA0070E

2010 Pathfinder

ENGINE COOLANT

CO-13

< ON-VEHICLE MAINTENANCE >

[VQ40DE]

4. When draining all of the coolant in the system for engine

removal or repair, it is necessary to drain the cylinder block.

Remove the cylinder block drain plugs (A), (B), (C), (D) and

block heater if equipped, to drain the cylinder block as shown.

NOTE:

For Canada, the (D) cylinder block drain plug as shown, is not a

cylinder block drain plug but a block heater.

5. Remove the reservoir tank to drain the engine coolant, then clean the reservoir tank before installing it.
6. Check the drained coolant for contaminants such as rust, corrosion or discoloration.

If the coolant is contaminated, flush the engine cooling system. Refer to

CO-12, "Changing Engine Cool-

ant"

REFILLING ENGINE COOLANT

1. Close the radiator drain plug. Install the reservoir tank, cylinder

block drain plugs (A), (B), (C), (D) and block heater if equipped,

if removed for a total system drain or for engine removal or

repair.

• The radiator must be completely empty of coolant and water.

• Apply sealant to the threads of the cylinder block drain plugs

(A), (B), (C), (D). Use Genuine High Performance Thread

Sealant or equivalent. Refer to