Content .. 365 366 367 368 ..

Nissan Pathfinder (2008 year). Manual - part 367

CYLINDER HEAD

EM-99

< ON-VEHICLE REPAIR >

[VQ40DE]

Valve Stem Diameter

Measure the diameter of valve stem with micrometer.

Valve Guide Inner Diameter

Measure the inner diameter of valve guide with inside micrometer.

Valve Guide Clearance

(Valve guide clearance) = (Valve guide inner diameter) – (Valve stem diameter).

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

replaced, follow the "VALVE GUIDE REPLACEMENT" procedure.

VALVE GUIDE REPLACEMENT

When valve guide is removed, replace with oversized [0.2 mm (0.008 in)] valve guide.

To remove valve guide, heat cylinder head to 110

to 130

(230

to 266

F) by soaking in heated oil.

Drive out valve guide with a press [under a 20 kN (2 ton, 2.2 US
ton, 2.0 Imp ton) pressure] or hammer and valve guide drift
(commercial service tool).

CAUTION:

Cylinder head contains heat. When working, wear protec-
tive equipment to avoid getting burned.

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 (0.003 in)

Exhaust

: 0.09 mm (0.004 in)

SEM008A

SEM931C

EM-100

< ON-VEHICLE REPAIR >

[VQ40DE]

CYLINDER HEAD

Ream cylinder head valve guide hole; using suitable reamer.

Heat cylinder head to 110

to 130

C (230

to 266

F) by soaking

in heated oil.

Press valve guide from camshaft side to the dimensions as
shown using suitable tool.

CAUTION:

Cylinder head contains heat. When working, wear protec-
tive equipment to avoid getting burned.

Apply reamer finish to valve guide using suitable reamer.

VALVE SEAT CONTACT

Valve guide hole diameter (for service parts):

Intake and exhaust

: 10.175 - 10.196 mm (0.4006 - 0.4014 in)

SEM932C

SEM008A

Projection “L”

Intake and exhaust

: 12.6 - 12.8 mm (0.496 - 0.504 in)

SEM950E

Standard:

Intake and exhaust

: 6.000 - 6.018 mm (0.2362 - 0.2369 in)

SEM932C

CYLINDER HEAD

EM-101

< ON-VEHICLE REPAIR >

[VQ40DE]

• After confirming that the dimensions of valve guides and valves are

within the specifications, perform this procedure.

• Apply prussian blue (or white lead) onto contacting surface of valve

seat to check the condition of the valve contact on the surface.

• Check if the contact area band is continuous all around the circum-

ference.

• If not, grind to adjust valve fitting and check again. If the contacting

surface still has “NG” conditions even after the re-check, replace
valve seat. Follow the "VALVE SEAT REPLACEMENT" procedure.

VALVE SEAT REPLACEMENT

When valve seat is removed, replace with oversized [0.5 mm (0.020 in)] valve seat.

Bore out old seat until it collapses. Boring should not continue beyond the bottom face of the seat recess
in cylinder head. Set the machine depth stop to ensure this. Refer to

EM-132, "Standard and Limit"

CAUTION:

Prevent to scratch cylinder head by excessive boring.

Ream cylinder head recess diameter for service valve seat.

• Be sure to ream in circles concentric to valve guide center.

This will enable valve to fit correctly.

Heat cylinder head to 110

to 130

C (230

to 266

F) by soaking

in heated oil.

Provide valve seats cooled well with dry ice. Force fit valve seat into cylinder head.

CAUTION:

• Avoid directly touching cold valve seats.
• Cylinder head contains heat. When working, wear protective equipment to avoid getting burned.

Finish seat to the specified dimensions using suitable tool. Refer
to

EM-132, "Standard and Limit"

CAUTION:

When using valve seat cutter, firmly grip cutter handle with
both hands. Then, press on the contacting surface all
around the circumference to cut in a single drive. Improper
pressure on with cutter or cutting many different times may
result in staged valve seat.

Using compound, grind to adjust valve fitting.

SBIA0322E

Oversize [0.5 mm (0.020 in)]

Intake

: 38.500 - 38.516 mm (1.5157 - 1.5164 in)

Exhaust

: 32.700 - 32.716 mm (1.2874 - 1.2880 in)

SEM795A

SEM008A

SEM934C

EM-102

< ON-VEHICLE REPAIR >

[VQ40DE]

CYLINDER HEAD

Check again for normal contact. Follow the "VALVE SEAT CONTACT" procedure.

VALVE SPRING SQUARENESS

• Set try square along the side of valve spring and rotate spring.

Measure the maximum clearance between the top face of spring
and try square.

• If it exceeds the limit, replace valve spring.

VALVE SPRING DIMENSIONS AND VALVE SPRING PRESSURE LOAD

• Check valve spring pressure at the specified spring height.

• If the installation load or load with valve open is out of the standard, replace valve spring.

Limit

: 2.1 mm (0.083 in)

PBIC0080E

Standard:

Intake and exhaust

Free height

: 47.07 mm (1.8531 in)

Installation height

: 37.00 mm (1.4567 in)

Installation load

: 166 - 188 N (16.9 - 19.2 kg, 37 - 42 lb)

Height during valve open

: 27.20 mm (1.0709 in)

Load with valve open

: 373 - 421 N (38.0 - 42.9 kg, 84 - 95 lb)

SEM113

ENGINE ASSEMBLY

EM-103

< REMOVAL AND INSTALLATION >

[VQ40DE]

REMOVAL AND INSTALLATION

ENGINE ASSEMBLY

Removal and Installation

INFOID:0000000001281996

WARNING:

• Situate vehicle on a flat and solid surface.
• Place chocks at front and back of rear wheels.
• For engines not equipped with engine slingers, attach proper slingers and bolts described in PARTS

CATALOG.

CAUTION:

• Always be careful to work safely, avoid forceful or uninstructed operations.

Rear engine mounting insulator 4WD

2. Rear engine mounting insulator 2WD

LH engine mounting bracket (upper)

LH heat shield plate

5. LH engine mounting insulator

LH engine mounting bracket (lower)

RH engine mounting bracket (lower)

8. RH engine mounting insulator

RH heat shield plate

10. RH engine mounting bracket (upper)

LBIA0432E

EM-104

< REMOVAL AND INSTALLATION >

[VQ40DE]

ENGINE ASSEMBLY

• Do not start working until exhaust system and engine coolant are cooled sufficiently.
• If items or work required are not covered by the engine section, follow the procedures in the applica-

ble sections.

• Always use the support point specified for lifting.
• Use either 2-point lift type or separate type lift. If board-on type is used for unavoidable reasons,

support at the rear axle jacking point with transmission jack or similar tool before starting work, in
preparation for the backward shift of center of gravity.

• For supporting points for lifting and jacking point at rear axle, refer to

GI-43, "Garage Jack and

Safety Stand"

REMOVAL

Preparation

Drain engine coolant. Refer to

CO-12, "Changing Engine Coolant"

Partially drain A/T fluid. Refer to

TM-182, "Changing the A/T Fluid (ATF)"

Release fuel pressure. Refer to

EC-481, "Fuel Pressure Check"

Remove the engine hood. Refer to

DLK-182, "Removal and Installation of Hood Assembly"

Remove engine room cover using power tools.

Remove the air duct and air cleaner case assembly. Refer to

EM-25, "Removal and Installation"

Disconnect vacuum hose between vehicle and engine and set it aside.

Remove the radiator assembly and hoses. Refer to

CO-16, "Removal and Installation"

Remove the drive belts. Refer to

EM-13, "Removal and Installation"

10. Remove the engine cooling fan. Refer to

CO-19, "Removal and Installation (Crankshaft driven type)"

11. Disconnect the engine room harness from the engine side and set it aside for easier work.
12. Disconnect the engine harness grounds.

13. Disconnect the reservoir tank for power steering from engine and move it aside for easier work.

14. Disconnect power steering oil pump from engine. Move it from its location and secure with a rope for eas-

ier work. Refer to

ST-24, "Removal and Installation"

15. Remove the A/C compressor bolts and set aside. Refer to

HA-40, "Removal and Installation for Compres-

sor"

16. Disconnect brake booster vacuum line.

17. Disconnect EVAP line.

18. Disconnect the fuel hose at the engine side connection. Refer to

EM-47, "Removal and Installation"

19. Disconnect the heater hoses at cowl, and install plugs to avoid leakage of engine coolant.

20. Remove the A/T oil level indicator and indicator tube.

21. Remove front final drive assembly (4WD models). Refer to

DLN-343, "Removal and Installation"

22. Remove three way catalyst. Refer to

EM-31, "Removal and Installation"

23. Install engine slingers into left bank and right bank.

24. Remove transmission. Refer to

TM-225, "2WD : Removal and

Installation"

(2WD models) or

TM-228, "4WD : Removal and

Installation"

(4WD models).

25. Lift with hoist and secure the engine in position.
26. Remove engine assembly from vehicle, avoiding interference

with vehicle body.

CAUTION:

• Before and during this lifting, always check if any har-

nesses are left connected.

27. Remove the parts that may restrict installation of engine to engine stand.

NOTE:
The procedure is described assuming that you use a engine holding the surface, to which transmission is
installed.

Remove drive plate.

Engine slinger torque:

28.0 N·m (2.9 kg-m, 21 ft-lb)

WBIA0624E

ENGINE ASSEMBLY

EM-105

< REMOVAL AND INSTALLATION >

[VQ40DE]

• Holding crankshaft pulley bolts, lock crankshaft to remove drive plate bolts.
• Loosen bolts diagonally.

CAUTION:

• Be careful not to damage drive plate. Especially avoid

deforming and damaging of signal plate teeth (circum-
ference position).

• Place the drive plate with signal plate surface facing

other than downward.

• Keep magnetic materials away from signal plate.

CAUTION:

Use an engine stand that has a load capacity [approximately 240kg (529 lb) or more] large enough
for supporting the engine weight.
• If the load capacity of the stand is not adequate, remove the following parts beforehand to

reduce the potential risk of overturning the stand.

- Remove fuel tube and fuel injector assembly. Refer to

EM-47, "Removal and Installation"

- Remove intake manifold. Refer to

EM-29, "Removal and Installation"

- Remove rocker cover. Refer to

EM-42, "Removal and Installation"

- Other removable brackets.

CAUTION:

Before removing the hanging chains, make sure the engine stand is stable and there is no risk of
overturning.

28. Remove generator. Refer to

CHG-21, "Removal and Installation"

29. Remove engine mounting insulator bracket (upper) with power tool.

INSTALLATION

Installation is in the reverse order of removal.

INSPECTION AFTER INSTALLATION

• Before starting engine, check the levels of engine coolant, engine oil and working fluid. If less than required

quantity, fill to the specified level.

• Use procedure below to check for fuel leakage.
• Turn ignition switch ON (with engine stopped). With fuel pressure applied to fuel piping, check for fuel leak-

age at connection points.

• Start engine. With engine speed increased, check again for fuel leakage at connection points.
• Run engine to check for unusual noise and vibration.
• Warm up engine thoroughly to make sure there is no leakage of engine coolant, engine oil, working fluid, fuel

and exhaust gas.

• Bleed air from passages in pipes and tubes of applicable lines, such as in cooling system.
• After cooling down engine, again check amounts of engine coolant, engine oil and working fluid. Refill to

specified level, if necessary.

• Summary of the inspection items:

*Transmission fluid, power steering fluid, brake fluid, etc.

KBIA2491E

Item

Before starting engine

Engine running

After engine stopped

Engine coolant

Level

Leakage

Level

Engine oil

Level

Leakage

Level

Working fluid

Level

Leakage

Level

Fuel

Leakage

Exhaust gas

—

Leakage

—

EM-106

< DISASSEMBLY AND ASSEMBLY >

[VQ40DE]

ENGINE UNIT

DISASSEMBLY AND ASSEMBLY

ENGINE UNIT

Disassembly and Assembly

INFOID:0000000001281997

Reinforcement plate

Drive plate

Rear oil seal

Sub harness

Knock sensor

Water connector

Cylinder block

Oil jet

Thrust bearing

10. Pilot converter

11. Main bearing

12. Crankshaft

13. Crankshaft key

14. Lower cylinder block

15. Lower cylinder block bolt

16. Connecting rod bolt

17. Connecting rod bearing cap

18. Connecting rod bearing

19. Connecting rod

20. Snap ring

21. Piston pin

22. Piston

23. Oil ring

24. Second ring

25. Top ring

WBIA0582E

Content .. 365 366 367 368 ..