Infiniti QX56 (Z62). Manual — part 236

CO-4

< SYSTEM DESCRIPTION >

DESCRIPTION

SYSTEM DESCRIPTION

DESCRIPTION

Engine Cooling System

INFOID:0000000006289654

JPBIA4247GB

DESCRIPTION

CO-5

< SYSTEM DESCRIPTION >

C

D

E

F

G

H

I

J

K

L

M

A

CO

N

P

O

Engine Cooling System Schematic

INFOID:0000000006289655

JPBIA4248GB

CO-6

< SYMPTOM DIAGNOSIS >

OVERHEATING CAUSE ANALYSIS

SYMPTOM DIAGNOSIS

OVERHEATING CAUSE ANALYSIS

Troubleshooting Chart

INFOID:0000000006289656

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 density

—

Insufficient engine coolant

Engine coolant leakage

Cooling hose

Loose clamp

Cracked hose

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 leakage into
cooling system

Cylinder head deterioration

Cylinder head gasket deteri-
oration

OVERHEATING CAUSE ANALYSIS

CO-7

< SYMPTOM DIAGNOSIS >

C

D

E

F

G

H

I

J

K

L

M

A

CO

N

P

O

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