2011 INFINITI QX56 Fuel

EM-66
< REMOVAL AND INSTALLATION >
TIMING CHAIN
NOTE:
 The above figure shows the relationship between the matching mark on each timing chain and that on the
corresponding sprocket, with the components installed.
 Parts with an identification mark (R or L) should be installed on the corresponding bank according to the
mark.
- Intake camshaft sprocket, exhaust camshaft sprocket
- Tension guide
- Slack guide
 To install timing chain and related parts, start with those on bank 2. The procedure for installing parts on
bank 1 is omitted because it is the same as that for installation on bank 2.
1. High pressure fuel pump camshaft 2. Intake camshaft sprocket (bank 2) 3. Exhaust camshaft sprocket (bank 2)
4. Timing chain (bank 2) 5. Slack guide (bank 2) 6. Chain oil jet (bank 2)
7. Timing chain tensioner (bank 2) 8. Crankshaft sprocket (bank 2 side) 9. Crankshaft sprocket (bank 1 side)
10. Chain oil jet (bank 1) 11. Tension guide (bank 1) 12. Timing chain (bank 1)
13. Exhaust camshaft sprocket (bank 1) 14. Intake camshaft sprocket (bank 1) 15. Timing chain tensioner (bank 1)
16. Slack guide (bank 1) 17. Tension guide (bank 2) 18. Dowel pin
A: Matching mark (copper link) B: Matching mark (punched) C: Matching mark (outer groove)
D: Matching mark (white link) E. Matching mark (notched) F. Matching mark (yellow link)
G. Crankshaft key
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Revision: 2010 May2011 QX56

TIMING CHAINEM-67
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1. Check that crankshaft key (1) and dowel pin (A) of each cam-
shaft are located as shown in the figure.
NOTE:
Though camshaft does not stop at the position as shown in the
figure, for the placement of cam nose, it is generally accepted
camshaft is placed for the same direction of the figure.
2. Install camshaft sprockets (INT and EXH).  Install onto correct side by checking with identification mark(A) on surface.
Exhaust side: Secure the hexagonal portion of exhaust camshaft using a wrench to tighten mounting bolt. Refer toEM-74, "
Exploded View".
Intake side:
 Secure the hexagonal portion (located in between journal No.1and journal No. 2) of drive shaft (A) using a wrench (B) to
tighten mounting bolt. Refer to EM-74, "
Exploded View".
NOTE:
The figure shows an example of bank 2.
3. Install high pressure fuel pump camshaft.
4. Install timing chains as per the following:
a. Install crankshaft sprockets for both banks.  Install each crankshaft sprocket so that its flange side (thelarger diameter side without teeth) (A) faces in the direction
shown in the figure.
NOTE:
The same parts are used but facing directions are different.Camshaft dowel pin
: At cylinder head upper face side in each bank
Crankshaft key : Straight up
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: Engine front
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1 : Crankshaft sprocket (bank 1 side)
2 : Crankshaft sprocket (bank 2 side)
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Revision: 2010 May2011 QX56

TIMING CHAINEM-71
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 Bolt (A) of fuel pump connector protector (1) cannot be
installed after installing valve timing control cover. Therefore,
install fuel pump connector protector in advance, if it is being
removed.
a. Install new O-rings (1) on front cover.
b. Install new seal rings (1) in shaft grooves. CAUTION:
When replacing seal ring, replace all rings with new ones.
c. Apply a continuous bead of liquid gasket with tube presser (commercial service tool) to valve timing control covers as
shown in the figure.
Use Genuine RTV silicone seal ant or equivalent. Refer to
GI-22, "
Recommended Chemical Products and Sealants".
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A : Bank 1
B : Bank 2
c: φ3.4 - 4.4 mm (0.134 - 0.173 in)
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Revision: 2010 May2011 QX56

TIMING CHAINEM-73
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Check for cracks and any excessive
wear at link plates and roller
links of timing chain. Replace timing chain if necessary.
INSPECTION AFTER ASSEMBLY
Inspection for Leakage
The following are procedures for chec king fluid leakage, lubricant leakage. Before starting engine, check oil/fluid levels including engine coolant and engine oil. If any are less than the
required quantity, fill them to the specified level. Refer to MA-10, "
Fluids and Lubricants".
 Follow the procedure below to check for fuel leakage.
- Turn ignition switch to the “ON” position (with engi ne stopped). With fuel pressure applied to fuel piping,
check for fuel leakage 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.
NOTE:
If hydraulic pressure inside chain tensioner drops after removal/installation, slack in guide may generate a
pounding noise during and just after the engine start. However, this does not indicate a malfunction. The
noise will stop after hydraulic pressure rises.
 Warm up engine thoroughly to check that there is no leak age of fuel, or any oil/fluids including engine oil and
engine coolant.
 Bleed air from lines and hoses of applicable lines, such as in cooling system.
 After cooling down engine, again check oil/fluid levels including engine oil and engine coolant. Refill them to the specified level, if necessary.
Summary of the inspection items:
* Power steering fluid, brake fluid, etc. A: Crack
B: Wear
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Items Before starting engine Engine running After engine stopped
Engine coolant Level Leakage Level
Engine oil Level Leakage Level
Transmission /
transaxle fluid AT & CVT Models Leakage Level / Leakage Leakage
MT Models Level / Leakage Leakage Level / Leakage
Other oils and fluids* Level Leakage Level
Fuel Leakage Leakage Leakage
Revision: 2010 May2011 QX56

EM-84
< REMOVAL AND INSTALLATION >
CAMSHAFT
 Move control shaft (A) to the small stopper and large stopper tocheck that the control shaft functions smoothly.
CAUTION:
Turn VVEL ladder assembly upside down to prevent the drive
shaft from dropping off.
RINK CHECK FOR BACK-LASH (BONDING) Check that the link and the shaft of drive shaft and control shaft are
not fixed.
 Check this by moving drive shaft and control shaft in the axial and
rotation directions.
 If there is an unusualness related to the above three items, replace VVEL ladder assembly & cylinder head
assembly.
NOTE:
VVEL ladder assembly cannot be replaced as a singl e part, because it is machined together with cylinder
head assembly.
INSPECTION AFTER ASSEMBLY
Inspection of Camshaft Sprocket (INT) Oil Groove
CAUTION:
 Perform this inspection only when DTC P0011, P 0021 are detected in self-diagnostic results of CON-
SULT-III and it is directed according to inspection procedure of EC section. Refer to EC-177, "
DTC
Logic".
 Check when engine is cold to prevent burns from the splashing engine oil.
1. Check engine oil level. Refer to LU-7, "
Inspection".
2. Perform the following procedure to prevent the engine from being unintentionally started while checking.
a. Release the fuel pressure. Refer to EC-153, "
Work Procedure".
b. Disconnect ignition coil and injector harness connectors.
3. Remove valve timing control solenoid valve. Refer to EM-61, "
Exploded View".
4. Crank engine, and then check that engine oil comes out from valve timing control solenoid valve hole (A). End crank after
checking.
WARNING:
Be careful not to touch rotati ng parts (drive belt, idler pul-
ley, and crankshaft pulley, etc.).
CAUTION:
 Prevent splashing by using a shop cloth to prevent the worker from injury from en gine oil and to prevent engine
oil contamination.
 Prevent splashing by using a shop cloth to prevent engine oil from being splashed to engine and
vehicle. Especially, be careful not to apply engine oil to rubber parts of drive belt, engine mount-
ing insulator, etc. Wipe engine oil out immediately if it is splashed.
: Engine front
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1 : Valve timing control cover (bank 2)
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Revision: 2010 May2011 QX56

CAMSHAFTEM-85
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5. Perform the following inspection if engine oil does not
come out from valve timing control solenoid valve
oil hole of the valve timing control cover.
 Remove oil filter, and then clean it. Refer to EM-61, "
Exploded View".
 Clean oil groove between oil strainer and valve timing control solenoid valve. Refer to LU-5, "
Engine
Lubrication System" and LU-6, "Engine Lubrication System Schematic".
6. Remove components between valve timing control solenoid valve and camshaft sprocket, and then check each oil groove for clogging.
 Clean oil groove if necessary. Refer to LU-5, "
Engine Lubrication System" and LU-6, "Engine Lubrica-
tion System Schematic".
7. After inspection, install removed parts in the reverse order.
Inspection for Leakage
The following are procedures for chec king fluid leakage, lubricant leakage.
 Before starting engine, check oil/fluid levels including engine coolant and engine oil. If any are less than the
required quantity, fill them to the specified level. Refer to MA-10, "
Fluids and Lubricants".
 Follow the procedure below to check for fuel leakage.
- Turn ignition switch to the “ON” position (with engi ne stopped). With fuel pressure applied to fuel piping,
check for fuel leakage 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. NOTE:
If hydraulic pressure inside chain tensioner drops after removal/installation, slack in guide may generate a
pounding noise during and just after the engine start. However, this does not indicate a malfunction. The
noise will stop after hydraulic pressure rises.
 Warm up engine thoroughly to check that there is no leak age of fuel, or any oil/fluids including engine oil and
engine coolant.
 Bleed air from lines and hoses of applicable lines, such as in cooling system.
 After cooling down engine, again check oil/fluid levels including engine oil and engine coolant. Refill them to
the specified level, if necessary.
Summary of the inspection items:
* Power steering fluid, brake fluid, etc. Items Before starting engine Engine running After engine stopped
Engine coolant Level Leakage Level
Engine oil Level Leakage Level
Transmission /
transaxle fluid AT & CVT Models Leakage Level / Leakage Leakage
MT Models Level / Leakage Leakage Level / Leakage
Other oils and fluids* Level Leakage Level
Fuel Leakage Leakage Leakage
Revision: 2010 May2011 QX56

EM-94
< REMOVAL AND INSTALLATION >
CYLINDER HEAD
 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 (EXH). Refer to EM-86, "
Exploded View". (Exhaust
side)
- If not, replace VVEL ladder assembly & cylinder head assembly. Refer to EM-86, "
Exploded View". (Intake side)
NOTE:
Since the valve seat (INT) cannot be replaced by t he piece, VVEL ladder assembly & cylinder head assem-
bly replacement are required.
Valve Spring (with valve spring seat) Squareness
 Set a try square (A) along the side of valve spring (with valve
spring seat) and rotate spring. Measure the maximum clearance
between the top of spring and try square.
 If it exceeds the limit.
- Replace valve spring (with valve spring seat) (EXH). Refer to EM-
86, "Exploded View". (Exhaust side)
- Replace VVEL ladder assembly & cylinder head assembly. Refer
to EM-86, "
Exploded View". (Intake side)
NOTE:
Since the valve spring (with valve spring seat) (INT) c annot be replaced by the piece, VVEL ladder assembly
& cylinder head assembly replacement are required.
Valve Spring Dimensions and Valve Spring Pressure Load
 Check the valve spring (with valve spring seat) pressure at speci- fied spring height.
 If the installation load or load with valve open is out of the stan- dard.
- Replace valve spring (with valve spring seat) (EXH). Refer to EM-
86, "Exploded View". (Exhaust side)
- Replace VVEL ladder assembly & cylinder head assembly. Refer to EM-86, "
Exploded View". (Intake side)
NOTE:
Since the valve spring (with valve spring seat) (INT) c annot be replaced by the piece, VVEL ladder assembly
& cylinder head assembly replacement are required.
INSPECTION AFTER ASSEMBLY
Inspection for Leakage
The following are procedures for checking fluid leakage, lubricant leakage.
 Before starting engine, check oil/fluid levels includi ng engine coolant and engine oil. If any are less than the
required quantity, fill them to the specified level. Refer to MA-10, "
Fluids and Lubricants".
 Follow the procedure below to check for fuel leakage.
- Turn ignition switch to the “ON” position (with engi ne stopped). With fuel pressure applied to fuel piping,
check for fuel leakage at connection points.
- Start engine. With engine speed increased, che ck again for fuel leakage at connection points.
 Run engine to check for unusual noise and vibration. NOTE:
A: OK
B: NG
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B : Contact
Limit : Refer to EM-135, "CylinderHead".
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Standard
: Refer to EM-135, "
CylinderHead".
SEM113
Revision: 2010 May2011 QX56

CYLINDER HEADEM-95
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If hydraulic pressure inside chain tensioner drops after removal/installation, slack in guide may generate a
pounding noise during and just after the engine start. However, this does not indicate a malfunction. The
noise will stop after hydraulic pressure rises.
 Warm up engine thoroughly to check that there is no leak age of fuel, or any oil/fluids including engine oil and
engine coolant.
 Bleed air from lines and hoses of applicable lines, such as in cooling system.
 After cooling down engine, again check oil/fluid levels including engine oil and engine coolant. Refill them to
the specified level, if necessary.
Summary of the inspection items:
* Power steering fluid, brake fluid, etc. Items Before starting engine Engine running After engine stopped
Engine coolant Level Leakage Level
Engine oil Level Leakage Level
Transmission /
transaxle fluid AT & CVT Models Leakage Level / Leakage Leakage
MT Models Level / Leakage Leakage Level / Leakage
Other oils and fluids* Level Leakage Level
Fuel Leakage Leakage Leakage
Revision: 2010 May2011 QX56