Infiniti QX56 (Z62). Manual - part 237

CO-8

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ENGINE COOLANT

PERIODIC MAINTENANCE

ENGINE COOLANT

Inspection

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LEVEL 

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

to “MAX” when the engine is cool.

• Adjust the engine coolant level if necessary.

WARNING:

Never remove reservoir tank cap when engine is hot.

LEAKAGE

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

radiator cap tester and radiator cap tester adapter (commercial
service tool) (A).

WARNING:

Never remove radiator cap and reservoir tank cap when
engine is hot. Serious burns could occur from high-pressure
engine coolant escaping from water inlet.

CAUTION:

Higher test pressure than specified may cause radiator dam-
age.
NOTE:
In a case that engine coolant decreases, fill radiator with engine coolant.

• If anything is found, repair or replace damaged parts.

Draining

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WARNING:

• Never remove radiator cap and reservoir tank cap when engine is hot. Serious burns could occur

from high-pressure engine coolant escaping from radiator.

• Wrap a thick cloth around the caps. Slowly turn them a quarter of a turn to release built-up pressure.

Carefully remove the caps by turning it all the way.

1.

Open radiator drain plug (1) at the bottom of radiator, and then
remove radiator cap and reservoir tank cap. 

When draining all of engine coolant in the system, open water drain plug on cylinder block. Refer
to 

EM-103, "Setting"

.

2.

Remove reservoir tank if necessary, and drain engine coolant and clean reservoir tank before installing. 

A

:  MAX

B

:  MIN

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Testing pressure

: Refer to 

CO-23, "Radiator"

.

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: Front under cover

: Vehicle front

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ENGINE COOLANT

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3.

Check drained engine coolant for contaminants such as rust, corrosion or discoloration.
If contaminated, flush the engine cooling system. Refer to 

CO-10, "Flushing"

.

Refilling

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1.

Install reservoir tank if removed, and radiator drain plug.

CAUTION:

Be sure to clean drain plug and install with new O-ring. Refer to 

CO-13, "Exploded View"

.

If water drain plug on cylinder block is removed, close and tighten it. Refer to 

EM-107, "Disassem-

bly and Assembly"

.

2.

Check that each hose clamp is firmly tightened.

3.

Remove air relief plug (1) on heater hose.

4.

Fill radiator, and reservoir tank, to specified level.
• Pour engine coolant through engine coolant filler neck

slowly of less than 3  (2-5/8 lmp qt) a minute to allow air
in system to escape.

• Use Genuine NISSAN Long Life Antifreeze/Coolant or

equivalent mixed with water (distilled or demineralized).
Refer to 

MA-10, "Fluids and Lubricants"

.

5.

When engine coolant overflows air relief hole on heater hose, install air relief plug with clamp. Then refill
radiator with engine coolant.

6.

Install radiator cap.

7.

Install reservoir tank cap.

8.

Warm up engine until opening thermostat less than 3,000 rpm. 
• Check thermostat opening condition by touching radiator hose (lower) to see a flow of warm water.

CAUTION:

: 1.96 N·m (0.2 kg-m, 17 in-lb)

2.

Engine cover

: Vehicle front

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Engine coolant capacity

: Refer to 

CO-23, 

"Periodical Maintenance S
pecification"

.

(With reservoir tank at 
“MAX” level)

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Reservoir tank engine 
coolant capacity

:Refer to 

CO-23, 

"Periodical Maintenance Sp
ecification"

.

(At “MAX” level)

A

: MAX 

B

:  MIN

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CO-10

< PERIODIC MAINTENANCE >

ENGINE COOLANT

Watch water temperature gauge so as not to overheat engine.

9.

Stop the engine and cool down to less than approximately 50

°

C (122

°

F).

• Cool down using fan to reduce the time.
• If necessary, refill radiator up to filler neck with engine coolant.

10. Refill reservoir tank to “MAX” level line with engine coolant if necessary.
11. Repeat steps 6 through 10 two or more times with reservoir tank cap installed until engine coolant level no

longer drops. 

12. Check cooling system for leakage with engine running.

13. Warm up the engine, and check for sound of engine coolant flow while running engine from idle up to

3,000 rpm with heater temperature controller set at several position between “COOL” and “WARM”.
• Sound may be noticeable at heater unit.

14. Repeat step 13 three times.
15. If sound is heard, bleed air from cooling system by repeating step 4, and steps from 6 to 14 until engine

coolant level no longer drops. 

Flushing

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1.

Install reservoir tank if removed, and radiator drain plug.

CAUTION:

Be sure to clean drain plug and install with new O-ring. Refer to 

CO-13, "Exploded View"

.

If water drain plug on cylinder block is removed, close and tighten it. Refer to 

EM-107, "Disassem-

bly and Assembly"

.

2.

Remove air relief plug (1) on heater hose.

3.

Fill radiator and reservoir tank with water until water spills from the air relief holes, then close air relief
plugs with clamp. Fill radiator and reservoir tank with water and reinstall caps.

4.

Run the engine and warm it up to normal operating temperature.

5.

Rev the engine two or three times under no-load.

6.

Stop the engine and wait until it cools down.

7.

Drain water from the system. Refer to 

CO-8, "Draining"

.

8.

Repeat steps 1 through 7 until clear water begins to drain from radiator.

: 1.96 N·m (0.2 kg-m, 17 in-lb)

2.

Engine cover

: Vehicle front

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RADIATOR

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RADIATOR

RESERVOIR TANK CAP

RESERVOIR TANK CAP : Inspection

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• Check valve seat of reservoir tank cap. 
- Check if valve seat (A) is swollen to the extent that the edge of the

metal plunger (B) cannot be seen when watching it vertically from
the top.

- Check if valve seat has no soil and damage.

• Pull negative-pressure valve to open it, and check that it close

completely when released.

- Check that there is no dirt or damage on the valve seat of reservoir

tank cap negative-pressure valve. 

- Check that there are no unusualness in the opening and closing

conditions of negative-pressure valve.

• Check reservoir tank cap relief pressure.
- When connecting reservoir tank cap to the radiator cap tester

(commercial service tool) and the radiator cap tester adapter (com-
mercial service tool) (A), apply engine coolant to the cap seal sur-
face. 

• Replace reservoir tank cap if there is an unusualness related to the above three.

CAUTION:

When installing reservoir tank cap, thoroughly wipe out the water inlet filler neck to remove any waxy
residue or foreign material.

RADIATOR

RADIATOR : Inspection

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Check radiator for mud or clogging. If necessary, clean radiator as per the following:
• Be careful not to bend or damage radiator fins.
• When radiator is cleaned without removal, remove all surrounding parts such as radiator cooling fan shroud.

Then tape 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.

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SMA967B

Standard and limit

: Refer to 

CO-23, "Radiator"

.

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