Infiniti FX35 / FX45. Manual - part 646

CYLINDER HEAD

EM-101

< SERVICE INFORMATION >

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• If the engine speed is out of the specified range, check battery liquid for proper gravity. Check the

engine speed again with normal battery gravity. 

• If compression pressure is below minimum value, check valve clearances and parts associated with

combustion chamber (valve, valve seat, piston, piston ring, cylinder bore, cylinder head, cylinder head
gasket). After the checking, measure compression pressure again.

• If some cylinder has low compression pressure, pour 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, piston rings may be worn out or damaged. Check pis-

ton rings and replace if necessary.

- If the compression pressure remains at low level despite the addition of engine oil, valves may be mal-

functioning. Check valves for damage. Replace 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, cylinder head gaskets are leaking. In such a case, replace cyl-
inder head gaskets.

9.

After inspection is completed, install removed parts.

10. Start the engine, and make sure that the engine runs smoothly.

11. Perform trouble diagnosis. If DTC appears, erase it. Refer to 

EC-89, "Trouble Diagnosis Introduction"

.

Component

INFOID:0000000001325738

Removal and Installation

INFOID:0000000001325739

REMOVAL

1.

Remove camshaft. Refer to 

EM-83, "Component"

.

NOTE:
It is also possible to perform the following steps 2 and 3 just before removing camshaft.

2.

Temporarily fit front suspension member to support engine. Refer to 

FSU-16, "Removal and Installation"

.

CAUTION:

1.

Engine rear lower slinger 

2.

Cylinder head (left bank)

3.

Cylinder head bolt

4.

Cylinder head (right bank)

5.

Cylinder head gasket (right bank)

6.

Cylinder head gasket (left bank)

7.

Oil level gauge guide

SBIA0581E

EM-102

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CYLINDER HEAD

Temporary fitting means the status that engine is adequately stable though the hoist is released
from hanging.
NOTE:
At the time of the start of this procedure front suspension member is removed, and cylinder head is
hanged by hoist with the engine slinger installed.

3.

Release the hoist from hanging, then remove the engine slinger.

4.

Remove the following parts:
• Fuel tube and fuel injector assembly: Refer to 

EM-45, "Component"

.

• Intake manifold: Refer to 

EM-24, "Component"

.

• Exhaust manifold: Refer to 

EM-26, "Component"

.

• Water inlet and thermostat assembly: Refer to 

CO-27, "Component"

.

• Water outlet, water pipe and heater pipe: Refer to 

CO-29, "Component"

.

5.

Remove cylinder head bolts in reverse order as shown in the fig-
ure with cylinder head bolt wrench (commercial service tool) and
power tool to remove cylinder heads (right and left banks).

6.

Remove cylinder head gaskets.

INSPECTION AFTER REMOVAL

Cylinder Head Bolts Outer Diameter

• Cylinder head bolts are tightened by plastic zone tightening

method. Whenever the size difference between “d1” and “d2”
exceeds the limit, replace them with new one. 

• If reduction of outer diameter appears in a position other than “d2”,

use it as “d2” point.

Cylinder Head Distortion

NOTE:
When performing this inspection, cylinder block distortion should be also checking. Refer to 

EM-138, "Inspec-

tion After Disassembly"

.

1.

Using a scraper, wipe off oil, scale, gasket, sealant and carbon deposits from surface of cylinder head.

CAUTION:

Do not allow gasket fragments to enter engine oil or engine coolant passages.

PBIC2057E

Limit (“d1” – “d2”)

: 0.11 mm (0.0043 in)

PBIC2480E

CYLINDER HEAD

EM-103

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2.

At each of several locations on bottom surface of cylinder head,
measure the distortion in six directions.

• If it exceeds the limit, replace cylinder head.

INSTALLATION

1.

Install new cylinder head gaskets.

2.

Turn crankshaft until No. 1 piston is set at TDC.
• Crankshaft key should line up with the right bank cylinder cen-

ter line as shown in the figure.

3.

Install cylinder head follow the steps below to tighten cylinder
head bolts in numerical order as shown in the figure with cylin-
der head bolts wrench (commercial service tool).

CAUTION:

If cylinder head bolts re-used, check their outer diameters
before installation. Refer to "Cylinder Head Bolts Outer
Diameter".

a.

Apply new engine oil to threads and seat surfaces of cylinder
head bolts.

b.

Tighten all cylinder head bolts.

c.

Completely loosen all cylinder head bolts.

CAUTION:

In step “c”, loosen bolts in reverse order of that indicated in
the figure.

d.

Tighten all cylinder head bolts.

Limit

: 0.1 mm (0.004 in)

SEM861E

SEM532G

 : 98.1 N·m (10 kg-m, 72 ft-lb)

 : 0 N·m (0 kg-m, 0 ft-lb)

 : 39.2 N·m (4.0 kg-m, 29 ft-lb)

PBIC2057E

EM-104

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CYLINDER HEAD

e.

Turn all cylinder head bolts 90 degrees clockwise (angle tighten-
ing).

CAUTION:

Check the tightening angle by using the angle wrench
(SST). Avoid judgment by visual inspection without SST.
• Check tightening angle indicated on the angle wrench indica-

tor plate.

f.

Turn all cylinder head bolts 90 degrees clockwise again (angle
tightening).

4.

After installing cylinder head, measure distance between front
end faces of cylinder block and cylinder head (left and right
banks).

• If measured value is out of the standard, re-install cylinder

head.

5.

Install in the reverse order of removal after this step.

INSPECTION AFTER INSTALLATION

Inspection for Leaks

The following are procedures for checking fluids leak, lubricates leak and exhaust gases leak.

• Before starting engine, check oil/fluid levels including engine coolant and engine oil. If less than required

quantity, fill to the specified level. Refer to 

MA-9, "Fluids and Lubricants"

.

• 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 fuel, exhaust gases, or any oil/fluids includ-

ing 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 to the

specified level, if necessary.

Summary of the inspection items:

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

PBIC0888E

Standard

: 14.1 - 14.9 mm (0.555 - 0.587 in) 

EMQ0662D

Items

Before starting engine

Engine running

After engine stopped

Engine coolant

Level

Leakage

Level

Engine oil

Level

Leakage

Level

Other oils and fluid*

Level

Leakage

Level

Fuel

Leakage

Leakage

Leakage

Exhaust gases

—

Leakage

—