2006 INFINITI QX56 check engine

CO-6Revision: November 2009
OVERHEATING CAUSE ANALYSIS
2006 QX56
OVERHEATING CAUSE ANALYSISPFP:00012
Troubleshooting ChartEBS00RE6
SymptomCheck 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
paper clogging
Physical damage
Clogged radiator cooling
tube Excess foreign material
(rust, dirt, sand, etc.)
Water cut valve malfunction Excess foreign material
(rust, dirt, sand, etc.), phys-
ical damage
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 leaks 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 leaks into
cooling systemCylinder head deterioration
Cylinder head gasket dete-
rioration

OVERHEATING CAUSE ANALYSISCO-7
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Revision: November 2009 2006 QX56
Except cool-
ing system
parts mal-
function—
Overload on engine Abusive driving
High engine rpm under no
load
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
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

CO-10Revision: November 2009
ENGINE COOLANT
2006 QX56
ENGINE COOLANTPFP:KQ100
InspectionEBS00RE9
LEVEL CHECK

Check if the engine coolant reservoir tank level is within MIN to
MAX level when engine is cool.

Adjust engine coolant level as necessary.
CHECKING COOLING SYSTEM FOR LEAKS
WARNING:
Never remove the radiator or reservoir cap when the engine is hot. Serious burns could occur from
high-pressure engine 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

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 nega-
tive-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.
Changing Engine CoolantEBS00REA
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.
SMA412B
Tool number : EG17650301 (J-33984-A)
Leakage test pressure : 137 kPa (1.4 kg/cm, 20 psi)
WBIA0612E
Tool number : EG17650301 (J-33984-A)
Standard: 95 - 125 kPa (0.97 - 1.28 kg/cm
2 , 14 - 18 psi)
WBIA0611E

ENGINE COOLANTCO-11
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Revision: November 2009 2006 QX56
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 radiator filler cap. This is the only step required
when partially draining the cooling system (radiator only).
CAUTION:
Do not to allow the coolant to contact the drive belts.
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 RH cylinder block drain plug to drain the right bank
and the oil cooler hose to drain the left bank as shown.
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, "
FLUSHING COOLING
SYSTEM" .
REFILLING ENGINE COOLANT
1. Close the radiator drain plug. Install the reservoir tank, cylinder block drain plug, and the oil cooler hose, 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 plug. Use Genuine High Performance Thread
Sealant or equivalent. Refer to GI-46, "
Recommended Chemical Products and Sealants" .
2. Set the vehicle heater controls to the full HOT and heater ON position. Turn the vehicle ignition ON with the engine OFF as necessary to activate the heater mode.
3. Remove the vented reservoir cap and replace it with a non-vented reservoir cap before filling the cooling system.
WBIA0391E
PBIC0146E
WBIA0392E
Radiator drain plug : Refer to CO-14, "RADIATOR" .
RH cylinder block drain plug : Refer to EM-78, "
CYLINDER BLOCK" .

CO-12Revision: November 2009
ENGINE COOLANT
2006 QX56
4. Install the Tool by installing the radiator cap adapter onto theradiator neck opening. Then attach the gauge body assembly
with the refill tube and the venturi assembly to the radiator cap
adapter.
5. Insert the refill hose into the coolant mixture container that is placed at floor level. Make sure the ball valve is in the closed
position.

Use Genuine NISSAN Long Life Anti-freeze coolant or equiv-
alent, mixed 50/50 with distilled water or demineralized water.
Refer to MA-12, "
ANTI-FREEZE COOLANT MIXTURE
RATIO" .
6. Install an air hose to the venturi assembly, the air pressure must be within specification.
CAUTION:
The compressed air supply must be equipped with an air
dryer.
7. The vacuum gauge will begin to rise and there will be an audible hissing noise. During this process open the ball valve on the refill hose slightly. Coolant will be visible ris-
ing in the refill hose. Once the refill hose is full of coolant, close the ball valve. This will purge any air
trapped in the refill hose.
8. Continue to draw the vacuum until the gauge reaches 28 inches of vacuum. The gauge may not reach 28 inches in high altitude
locations, refer to the vacuum specifications based on the alti-
tude above sea level.
9. When the vacuum gauge has reached the specified amount, disconnect the air hose and wait 20 seconds to see if the system loses any vacuum. If the vacuum level drops, perform any necessary repairs to the
system and repeat steps 6 - 8 to bring the vacuum to the specified amount. Recheck for any leaks.
10. Place the coolant container (with the refill hose inserted) at the same level as the top of the radiator. Then open the ball valve on the refill hose so the coolant will be drawn up to fill the cooling system. The cooling
system is full when the vacuum gauge reads zero.
CAUTION:
Do not allow the coolant container to get too low when filling, to avoid air from being drawn into
the cooling system.
11. Remove the Tool from the radiator neck opening and install the radiator cap.
12. Remove the non-vented reservoir cap.
13. Fill the cooling system reservoir tank to the specified level. Run the engine to warm up the cooling system and top up the system as necessary before installing the vented reservoir cap.
FLUSHING COOLING SYSTEM
1. Drain the water from the engine cooling system. Refer to CO-11, "DRAINING ENGINE COOLANT" .
2. Fill the radiator and the reservoir tank (to the “MAX ” line), with water. Reinstall the radiator cap and leave
the vented reservoir cap off.
3. Run the engine until it reaches normal operating temperature. Cooling system capacity
(with reservoir)
: Refer to
MA-11, "
Fluids
and Lubricants" .
Compressed air
supply pressure : 5.7 - 8.5 kPa (5.6 - 8.4 kg/cm
2 ,
80 - 120 psi)
LLIA0058E
Altitude above sea level Vacuum gauge reading
0 - 100 m (328 ft) : 28 inches of vacuum
300 m (984 ft) : 27 inches of vacuum
500 m (1,641 ft) : 26 inches of vacuum
1,000 m (3,281 ft) : 24 - 25 inches of vacuum
LLIA0057E

CO-16Revision: November 2009
RADIATOR
2006 QX56
10. Lift up and remove the radiator.CAUTION:
Do not damage or scratch air conditioner condenser and
radiator core when removing.
INSTALLATION
Installation is in the reverse order of removal.
INSPECTION AFTER INSTALLATION

Check for leaks of engine coolant. Refer to CO-10, "CHECKING COOLING SYSTEM FOR LEAKS" .

Start and warm up the engine. Visually check for leaks of the engine coolant and A/T fluid.
Checking RadiatorEBS00REC
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, radi-
ator 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 vertically downward.
2. Apply water again to all radiator core surfaces.
3. Stop washing when dirt and debris no longer flow out from the radiator.
4. Blow air into the back side of radiator core vertically downward.

Use compressed air lower than 490 kPa (5 kg/cm2 , 71 psi) and keep distance more than 30 cm (11.8
in).
5. Blow air again into all the radiator core surfaces until no water sprays out.
PBIC1536E

ENGINE COOLING FANCO-17
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Revision: November 2009 2006 QX56
ENGINE COOLING FANPFP:21140
Removal and Installation (Crankshaft Driven Type)EBS00RED
REMOVAL
1. Remove the air duct and resonator assembly. Refer to EM-15, "Removal and Installation" .
2. Remove the engine front undercover using power tool.
3. Remove the lower radiator shroud. Refer to CO-14, "
Removal and Installation" .
4. Remove the drive belt. Refer to EM-13, "
Removal and Installation" .
5. Remove the cooling fan.
INSPECTION AFTER REMOVAL
Fan Coupling
Inspect fan coupling for oil leakage and bimetal conditions.
Fan Bracket

Visually check that there is no significant looseness in the fan
bracket shaft, and that it turns smoothly by hand.

If there are any unusual concerns, replace the cooling fan pulley.
INSTALLATION
Installation is in the reverse order of removal.

Install cooling fan with its front mark “F” facing front of engine. Refer to CO-17, "Removal and Installation
(Crankshaft Driven Type)" .
INSPECTION AFTER INSTALLATION

Check for leaks of the engine coolant. Refer to CO-10, "CHECKING COOLING SYSTEM FOR LEAKS" .
1. Cooling fan2. Fan coupling3. Fan bracket
4. Cooling fan pulley
WBIA0632E
SLC072
WBIA0418E

WATER PUMPCO-19
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Revision: November 2009 2006 QX56
WAT E R P U MPPFP:21020
Removal and InstallationEBS00REF
CAUTION:

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

Water pump cannot be disassembled and should be replaced as a unit.
REMOVAL
1. Drain engine coolant so that no engine coolant comes out from water pump fitting hole. Refer to CO-11,
"DRAINING ENGINE COOLANT" .
CAUTION:
Perform when the engine is cold.
2. Remove the engine front undercover using power tool.
3. Remove the air duct and resonator assembly. Refer to EM-15, "
Removal and Installation" .
4. Remove the drive belt. Refer to EM-13, "
Removal and Installation" .
5. Remove the water pump pulley.
6. Remove the water pump.

Engine coolant will leak from the cylinder block, so have a receptacle ready below.
CAUTION:
Handle water pump vane so that it does not contact any other parts.
INSPECTION AFTER REMOVAL

Visually check that there is no significant dirt or rust on the water
pump body and vane.

Make sure there is no looseness in the vane shaft, and that it
turns smoothly when rotated by hand.

Replace the water pump, if necessary.
INSTALLATION
Installation is in the reverse order of removal.
KBIA2543E
1. Gasket 2. Water pump3. Water pump pulley
KBIA2552E