Infiniti FX35, FX50 (S51). Manual - part 968

EM-172

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[VK50VE]

CAMSHAFT VALVE CLEARANCE

Crankshaft pulley mounting bolt flange has an angle mark (B)
every 90 degrees (c). They can be used as a guide to rotation
angle.

• By referring to the figure, measure the valve clearances at

locations marked “

” as shown in the table below (locations

indicated in the figure).

• No. 6 cylinder at compression TDC

Perform adjustment or replacement if the measured value is out of the standard.
• If a valve clearance on the exhaust side is out of specification, adjust the valve clearance. Refer to

EM-

236, "Inspection"

• If a valve clearance on the intake side is out of specification, replace VVEL ladder assembly & cylinder

head assembly. Refer to

EM-227, "Exploded View"

CAUTION:

Never adjust valve clearance on the intake side.
NOTE:
Since the valve lifter (INT) cannot be replaced by the piece, VVEL ladder assembly & cylinder head
assembly replacement are required.

: Paint mark

JPBIA2066ZZ

: Engine front

Measuring position [bank 2 (A)]

No. 2

CYL.

No. 4

CYL.

No. 6

CYL.

No. 8

CYL.

No. 6 cylinder at com-

pression TDC

EXH

(B)

(C)

INT

(D)

JPBIA2069ZZ

COMPRESSION PRESSURE

EM-173

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[VK50VE]

COMPRESSION PRESSURE

Inspection

INFOID:0000000005245218

Warm up engine thoroughly. Then, stop it.

Release fuel pressure. Refer to

EC-1236, "Inspection"

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

Remove engine cover. Refer to

EM-174, "Exploded View"

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

EM-191, "Exploded View"

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

Measure compression pressure using compression gauge connected with flexible type adapter (commer-
cial service tool).

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:

• Measure a six-cylinder under the same conditions since a measurement depends on measure-

ment conditions (engine water temperature, etc.).

• 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 the minimum value, check valve clearances and parts associated with

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

• If a cylinder has low compression pressure, pour a small amount of engine oil into the spark plug hole of

the cylinder to recheck 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. Refer to

EM-256, "Disassembly and Assembly"

- 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. Refer to

EM-256, "Dis-

assembly and Assembly"

• 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. Refer to

EM-246, "Disassembly and Assembly"