Infiniti FX35, FX50 (S51). Manual - part 931

EM-24

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CAMSHAFT VALVE CLEARANCE

• Thickness of new valve lifter can be identified by stamp marks

on the reverse side (inside the cylinder).
Stamp mark 788 indicates 7.88 mm (0.3102 in) in thickness.

Available thickness of valve lifter: 27 sizes with range 7.88 to 8.40 mm (0.3102 to 0.3307 in) in steps of
0.02 mm (0.0008 in) (when manufactured at factory). Refer to 

EM-143, "Camshaft"

.

6.

Install selected valve lifter.

7.

Install camshaft. Refer to 

EM-70, "Removal and Installation"

.

8.

Manually turn crankshaft pulley a few turns. 

9.

Check that the valve clearances for cold engine are within the specifications by referring to the specified
values. 

10. Install all removal parts in the reverse order of removal. 

11. Warm up the engine, and check for unusual noise and vibration.

A

:  Stamp

B

: Thickness of valve lifter

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COMPRESSION PRESSURE

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COMPRESSION PRESSURE

Inspection

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1.

Warm up engine thoroughly. Then, stop it.

2.

Release fuel pressure. Refer to 

EC-566, "Inspection"

.

3.

Disconnect fuel pump fuse (1) from IPDM E/R (2) to avoid fuel
injection during measurement.

4.

Remove engine cover with power tool. Refer to 

EM-27, "Exploded View"

.

5.

Remove ignition coil and spark plug from each cylinder. Refer to 

EM-50, "Exploded View"

.

6.

Connect engine tachometer (not required in use of CONSULT-III).

7.

Install compression gauge with an adapter (commercial service
tool) onto spark plug hole.

• Use the adapter hat has a smaller than 20 mm (0.79 in) (a) as

shown in the figure. Otherwise, it may be caught by cylinder
head during removal.

8.

With accelerator pedal fully depressed, turn ignition switch to “START” for cranking. When the gauge
pointer stabilizes, read the compression pressure and the engine rpm. Perform these steps to check each
cylinder.

CAUTION:

Always use a fully charged battery to obtain the specified engine speed.
• 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. Refer to 

PG-3, "How to Handle Battery"

.

• 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.

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a

: 20 mm (0.79 in)

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Compression pressure

: Refer to 

EM-142, "General Specification"

.

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COMPRESSION PRESSURE

• 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 check that the engine runs smoothly.

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

EC-134, "Description"

.

ENGINE COVER

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REMOVAL AND INSTALLATION

ENGINE COVER

Exploded View

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Removal and Installation

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REMOVAL

Loosen mounting bolts and nuts in the reverse order as shown in the
figure, and then remove engine cover.

CAUTION:

Never damage or scratch engine cover when installing or
removing.

INSTALLATION

Install engine cover, and then tighten mounting bolts and nuts in
numerical order as shown in the figure.

CAUTION:

Never damage or scratch engine cover when installing or
removing.

1

: Engine cover

Refer to 

GI-4, "Components"

 for symbols in the figure.

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