2008 INFINITI QX56 Stop

EM-18
< ON-VEHICLE MAINTENANCE >
CAMSHAFT VALVE CLEARANCE
CAMSHAFT VALVE CLEARANCE
Valve ClearanceINFOID:0000000001538810
INSPECTION
NOTE:
Perform the following inspection after removal, installation or replacement of camshaft or valve-related parts,
or if there are unusual engine conditions due to changes in valve clearance over time (starting, idling, and/or
noise).
1. Warm up the engine. Then stop the engine.
2. Remove the engine room cover. Refer to EM-24, "
Removal and Installation".
3. Remove the air cleaner and air duct assembly. Refer to EM-25, "
Removal and Installation".
4. Remove the RH bank and LH bank rocker covers using power tool. Refer to EM-38, "
Removal and Instal-
lation".
5. Turn the crankshaft pulley in the normal direction (clockwise when viewed from engine front) to align TDC identification notch
(without paint mark) with timing indicator.
6. At this time, make sure both the intake and exhaust cam noses of No. 1 cylinder (top front on LH bank) face outside.
• If they do not face outside, turn crankshaft pulley once more.
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COMPRESSION PRESSUREEM-23
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COMPRESSION PRESSURE
Checking Compression PressureINFOID:0000000001538811
1. Warm up the engine thoroughly. Then stop the engine.
2. Release the fuel pressure. Refer to EC-494, "
Fuel Pressure Check".
CAUTION:
If CONSULT-III is not used to release fuel pressure leave the fuel pump fuse disconnected until
step 7.
3. Remove the spark plug from each cylinder. Refer to EM-16, "
Removal and Installation".
4. Connect the engine tachometer (not required in use of CONSULT-III).
5. Install the compression tester with Tool into the spark plug hole.
6. With the accelerator pedal fully depressed, turn the ignition switch to “START” for cranking. When the gauge pointer stabi-
lizes, read the compression pressure and engine rpm. Perform
these steps to check each cylinder.
Unit: kPa (kg/cm2, psi) /rpm
CAUTION:
Always use a fully charged battery to obtain specified engine speed.
• If the engine speed is out of the specified range, check the battery liquid for proper gravity. Check the engine speed again with normal battery gravity.
• If the compression pressure is below the minimum value, check the valve clearances and parts associ-
ated with the combustion chamber (valve, valve seat , piston, piston ring, cylinder bore, cylinder head,
cylinder head gasket). After checking, measure the compression pressure again.
• If some cylinders have low compression pressure, pour a small amount of engine oil into the spark plug hole of the cylinder to re-check it for compression.
- If the added engine oil improves the compression, t he piston rings may be worn out or damaged. Check
the piston rings and replace if necessary.
- If the compression pressure remains at a low level despite the addition of engine oil, the valves may be malfunctioning. Check the valves for damage. Replace the valve or valve seat accordingly.
• If two adjacent cylinders have respectively low compression pressure and their compression remains low even after the addition of engine oil, the gaskets may be leaking, or a valve in adjacent cylinders
may be damaged. Inspect and repair as required.
7. Install the components in the reverse order of removal.
8. Start the engine and confirm that it runs smoothly.
9. Perform trouble diagnosis. If DTC appears, erase it. Refer to EC-75, "
Description".
Tool number : EG15050500 (J-45402)
Standard
MinimumDeference limit be-
tween cylinders
1,520 (15.5, 220) / 200 1,324 (13.5, 192) / 200 98 (1.0, 14) / 200WBIA0605E
Revision: March 2010 2008 QX56

INTAKE MANIFOLDEM-29
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5. Install the quick connector cap on the quick connector joint (on
engine side only).
6. Install the fuel hose and tube to hose clamps.
7. Refill the engine coolant. Refer to CO-11, "
Changing Engine
Coolant".
INSPECTION AFTER INSTALLATION
• After installing fuel tubes, make sure there is no fuel leakage at connections in the following steps.
- Apply fuel pressure to fuel lines by turning ignition switch ON (with engine stopped). Then check for fuel leaks at connections.
- Start the engine and rev it up and check for fuel leaks at the connections.
• Perform procedures for “Throttle Valve Closed Position Learning” after finishing repairs. Refer to EC-18,
"Throttle Valve Closed Position Learning".
• If electric throttle control actuator is replaced, per form procedures for “Idle Air Volume Learning” after finish-
ing repairs. Refer to EC-18, "
Idle Air Volume Learning".
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EM-36
< ON-VEHICLE REPAIR >
OIL PAN AND OIL STRAINER
4. Install the oil pan drain plug.
5. Install engine assembly. Refer to EM-78, "
Removal and Installation".
• Do not fill the engine oil for at least 30 minutes after oil pan is installed.
INSPECTION AFTER INSTALLATION
1. Check engine oil level and add engine oil if necessary. Refer to LU-8, "Inspection".
2. Start the engine, and check for leaks of engine oil.
3. Stop engine and wait for 10 minutes.
4. Check engine oil level again.
Revision: March 2010 2008 QX56

EM-42
< ON-VEHICLE REPAIR >
FUEL INJECTOR AND FUEL TUBE
• Lubricate O-ring with new engine oil.
• Do not clean O-ring with solvent.
• Make sure that O-ring and its mating part are free of foreign material.
• When installing O-ring, be careful not to scratch it with tool or fingernails. Also be careful not to
twist or stretch O-ring. If O-ring was stretc hed while it was being attached, do not insert it
quickly into fuel tube.
• Insert O-ring straight into fuel tube. Do not angle or twist it.
3. Install fuel injector to fuel tube.
a. Insert clip into clip mounting groove on fuel injector. • Insert clip so that lug “A” of fuel injector matches notch “A” ofthe clip.
CAUTION:
• Do not reuse clip. Replace it with a new one.
• Be careful to keep clip from interfering with O-ring. Ifinterference occurs, replace O-ring.
b. Insert fuel injector into fuel tube with clip attached. • Insert it while matching it to the axial center.
• Insert fuel injector so that lug “B” of fuel tube matches notch
“B” of the clip.
• Make sure that fuel tube flange is securely fixed in flange fixing groove on clip.
c. Make sure that installation is complete by checking that fuel injector does not rotate or come off.
• Make sure that protrusions of fuel injectors are aligned withcutouts of clips after installation.
4. Install fuel tube and fuel injector assembly to intake manifold. CAUTION:
Be careful not to let tip of injector nozzle come in contact with other parts.
• Tighten fuel tube assembly bolts “a” to “b” in illustration and in
two steps.
5. Install fuel hose assembly. • Follow the precautions for fuel injector when handling O-ring.
• Insert connectors straight, making sure that the axis is lined up with fuel tube side to prevent O-ring from
being damaged.
• Tighten bolts evenly in several steps.
• Make sure that there is no gap between flange and fuel tube after tightening bolts.
6. Installation of the remaining components is in the reverse order of removal.
INSPECTION AFTER INSTALLATION
After installing fuel tubes, make sure there are no fuel leaks at connections using the following steps.
1. Apply fuel pressure to fuel lines by turning ignition switch ON (with engine stopped). Then check for fuel leaks at connections.
2. Start the engine and rev it up and check for fuel leaks at connections. NOTE:
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1st step : 12.8 N·m (1.3 kg-m, 9 ft-lb)
2nd step : 24.5 N·m (2.5 kg-m, 18 ft-lb)
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FUEL INJECTOR AND FUEL TUBEEM-43
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Use mirrors for checking on hidden points.
CAUTION:
Do not touch the engine imme
diately after stopping, as engine becomes extremely hot.
Revision: March 2010 2008 QX56

TIMING CHAINEM-47
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8. Remove the oil pump drive spacer.
• Hold and remove the flat space of the oil pump drive spacer bypulling it forward.
9. Remove the oil pump. Refer to LU-14, "
Removal and Installation".
10. Remove the chain tensioner on the LH bank using the following steps. NOTE:
To remove the timing chain and associated parts, start with those on the LH bank. The procedure for
removing parts on the RH bank is omitted because it is the same as that for the LH bank.
a. Squeeze the return-proof clip ends using suitable tool and push the plunger into the tensioner body.
b. Secure the plunger using stopper pin. • Stopper pin is made from hard wire approximately 1 mm (0.04in) in diameter.
c. Remove the bolts and chain tensioner.
WARNING:
Plunger, spring, an d spring seat pop out when (squeezing)
return-proof clip without holding plunger head. It may
cause serious injuries. Always hold plunger head when
removing.
NOTE:
• Stop the plunger in the fully extended position by using the
return-proof clip (1) if the stopper pin is removed.
• Push the plunger (2) into the tensioner body while squeezing
the return-proof clip (1). Secure it using stopper pin (3).
11. Remove the timing chain tension guide and timing chain slack guide.
12. Remove the timing chain and crankshaft sprocket.
13. Loosen the camshaft sprocket bolts as shown and remove the camshaft sprocket.
CAUTION:
To avoid interference between valves and pistons, do not
turn crankshaft or camshaft wh en timing chain is discon-
nected.
14. Repeat the same procedure to remove the RH timing chain and associated parts.
INSPECTION AFTER REMOVAL
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Revision: March 2010 2008 QX56

TIMING CHAINEM-49
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1. Make sure the crankshaft key and RH bank camshaft dowel pin
and LH bank camshaft dowel pin are facing in the direction
shown.
2. Install the camshaft sprockets. • Install the intake camshaft sprocket (A) and exhaust camshaftsprockets (B) by selectively us ing the groove of the dowel pin
according to the bank. (Common part used for both banks.)
• Lock the hexagonal part of the camshaft in the same way as for removal, and tighten the bolts.
• A = I : Intake
• B = V: Exhaust
3. Install the crankshaft sprockets for both banks. • Install LH bank crankshaft sprocket (B) and RH bank crank-shaft sprocket (C) so that their flange side (A) (the larger diam-
eter side without teeth) faces in the direction shown.
NOTE:
The same parts are used but facing directions are different.
4. Install the timing chains and associated parts. • Align the alignment mark on each sprocket and the timing chain for installation.
CAUTION:
• Before installing timing chain tensioner, it is possible to change the position of alignment mark
on timing chain and each sprocket . After the alignment marks are aligned, keep them aligned
by holding them by hand.
• Install the slack guides and tension guides onto the correct side by checking the identification mark on
the surface.
• Install the timing chain tensioner with the plunger locked in with the stopper pin.
CAUTION:
• Before and after the installation of the timing chain tensioner, make sure that the alignment
mark on the timing chain is not out of alignment.
• After installing the timing chain tensioner, remove the stopp er pin to release the tensioner.
Make sure the tensioner is released.
• To avoid chain-link skipping of the timing chain, do not move crankshaft or camshafts until the
front cover is installed.
5. In the same way as for the RH bank, install the timing chain and associated parts on the LH bank.
6. Install the oil pump.
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Revision: March 2010 2008 QX56