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Infiniti QX56 (JA60). Manual - part 479

EM-70

< ON-VEHICLE REPAIR >

CYLINDER HEAD

• After cooling down the engine, again check oil/fluid levels including engine oil and engine coolant. Refill to

specified level if necessary.

• Summary of the inspection items:

*Transmission/transaxle/CVT fluid, power steering fluid, brake fluid, etc.

Exploded View

INFOID:0000000005149009

Disassembly and Assembly

INFOID:0000000005149010

DISASSEMBLY

1. Remove the spark plug. Refer to

EM-16, "Removal and Installation"

2. Remove the valve lifter.

• Identify the installation positions, and store them without mixing them up.

Item

Before starting engine

Engine running

After engine stopped

Engine coolant

Level

Leakage

Level

Engine oil

Level

Leakage

Level

Other oils and fluids*

Level

Leakage

Level

Fuel

Leakage

Exhaust gas

—

Leakage

—

Spark plug

Valve lifter

Valve collet

Valve spring retainer

Valve spring

Valve spring seat

Valve oil seal

Valve guide

Valve seat

10.

Valve (INT)

11. Valve (EXH)

12.

Cylinder head (LH bank)

13.

Spark plug tube

14. Cylinder head (RH bank)

WBIA0470E

CYLINDER HEAD

EM-71

< ON-VEHICLE REPAIR >

3. Remove the valve collet using Tools.

CAUTION:

When working, take care not to damage valve lifter holes.

4. Remove the valve spring retainer, valve spring and valve spring

seat.

5. Inspect the valve guide clearance. Refer to

EM-72, "Inspection After Disassembly"

6. Push the valve stem to the combustion chamber side, and remove the valve.

• Identify the installation positions, and store them without mixing them up.

7. Remove the valve oil seal using Tool.

8. Replace the valve seat if necessary. Refer to

EM-72, "Inspection After Disassembly"

9. Replace the valve guide if necessary. Refer to

EM-72, "Inspection After Disassembly"

10. Remove the spark plug tube, as necessary.

• Remove the spark plug tube out of the cylinder head using suitable tool.

CAUTION:

• Do not damage the cylinder head.

• Do not remove the spark plug tube unless absolutely necessary. Once removed, the spark plug

tube will be deformed and cannot be reused.

ASSEMBLY

1. Install the valve guide if necessary. Refer to

EM-72, "Inspection After Disassembly"

2. Install the valve seat if necessary. Refer to

EM-72, "Inspection After Disassembly"

3. Install the valve oil seal using Tool.

• Apply new engine oil on the new valve oil seal joint and seal

lip.

• Install the valve oil seal to the specified height "H".

4. Install the valves in their original position.
5. Install the valve spring seats.

Tool number

: KV10116200 (J-26336-A)
: KV10115900 (J-26336-20)
: KV10109220 ( — )

Tool number

: KV10107902 (J-38959)

WBIA0578E

WBIA0478E

Tool number

: KV10115600 (J-38958)

Height "H" (without valve spring installed)

Intake and exhaust

: 14.300 - 14.900 mm (0.5630 -
0.5870 in)

WBIA0490E

EM-72

< ON-VEHICLE REPAIR >

CYLINDER HEAD

6. Install the valve springs.

• Install the narrow pitch end (paint mark side) to the cylinder

head side.

7. Install the valve spring retainers.

8. Install the valve collet using Tools.

CAUTION:

When working, take care not to damage valve lifter holes.

9. Install the valve lifters.

• Install the removed parts in their original locations.

• If installing new lifters, select the correct size lifter for proper valve clearance. Refer to

EM-18, "Valve

Clearance"

10. Install the spark plug tube if necessary, following the procedure below.
a. Remove any old liquid gasket adhering to the cylinder-head spark plug tube hole.
b. Apply liquid gasket to area within approximately 12 mm (0.47 in) from the edge of the spark plug tube

press-fit side.

Use Genuine RTV Silicone Sealant or equivalent. Refer to

GI-15, "Recommended Chemical Prod-

ucts and Sealants"

Press-fit the spark plug tube to the specified height “H” using

suitable tool.

CAUTION:

• When press-fitting, take care not to deform the spark plug

tube.

• After press-fitting, wipe off any liquid gasket protruding

onto the cylinder-head upper face.

11. Install the spark plugs.

Inspection After Disassembly

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CYLINDER HEAD DISTORTION

1. Remove any oil, scale, gasket, sealant and carbon deposits from the cylinder head surface.

CAUTION:

Do not allow any debris to enter the oil or coolant passages.

SEM085D

Tool number

: KV10116200 (J-26336-A)
: KV10115900 (J-26336-20)
: KV10109220 ( — )

WBIA0578E

Standard press-fit height “H”

:38.400 - 39.400 mm
(1.512 - 1.551 in)

KBIA1248E

CYLINDER HEAD

EM-73

< ON-VEHICLE REPAIR >

2. Measure the bottom surface of the cylinder head for distortion in

six directions as shown, using suitable tools.

• If measurement exceeds the limit, replace the cylinder head.

VALVE DIMENSIONS

• Check the dimensions of each valve. Refer to

EM-108, "Standard

and Limit"

• If the dimensions are out of the standard, replace the valve.

VALVE GUIDE CLEARANCE

Valve Stem Diameter

Measure the diameter of the valve stem using suitable tool.

Valve Guide Inside Diameter

Measure the inside diameter of the valve guide using suitable tool.

Valve Guide Clearance

• (Valve guide clearance) = (Valve guide inside diameter) – (Valve stem diameter).

• If the calculated value exceeds the limit, replace valve and/or valve guide. When the valve guide must be

replaced, follow the valve guide replacement procedure.

Standard

: 0.03 mm (0.0012 in)

Limit

: 0.1 mm (0.004 in)

PBIC0075E

SEM188A

Standard

Intake

: 5.965 - 5.980 mm (0.2348 - 0.2354 in)

Exhaust

: 5.955 - 5.970 mm (0.2344 - 0.2350 in)

SEM938C

Standard

Intake and Exhaust

: 6.000 - 6.018 mm (0.2362 - 0.2369 in)

Valve guide clearance:
Standard

Intake

: 0.020 - 0.053 mm (0.0008 - 0.0021 in)

Exhaust : 0.030 - 0.063 mm (0.0012 - 0.0025 in)

Limit

Intake

: 0.08 mm (0.0031 in)

Exhaust : 0.09 mm (0.0035 in)

Content .. 477 478 479 480 ..