Nissan X-Trail 32. Manual — part 1050
CYLINDER HEAD
EM-97
< UNIT DISASSEMBLY AND ASSEMBLY >
[MR20DD]
C
D
E
F
G
H
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A
EM
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c.
Press valve guide
from camshaft side to dimensions as
shown in the figure.
CAUTION:
Cylinder head contains heat, wear protective equipment to
avoid getting burned.
d.
Apply reamer finish to valve guide with a valve guide reamer
(commercial service tool) (A).
2.
When valve seat is removed, install it.
CAUTION:
Replace with oversize [0.5 mm (0.020 in)] valve seat.
a.
Ream cylinder head
recess diameter for service valve seat
.
• Be sure to ream in circles concentric to the valve guide center.
This will enable valve seat to fit correctly.
b.
Heat cylinder head to 110 to 130
°
C (230 to 266
°
F) by soaking in
heated oil
.
c.
Provide valve seats cooled well with dry ice. Press-fit valve seat into cylinder head.
CAUTION:
• Never touch cold valve seats directly.
• Cylinder head contains heat, wear protective equipment to avoid getting burned.
: Cylinder head
Projection (H)
: Refer to
.
PBIC3217J
Standard
: Refer to
.
JPBIA0185ZZ
For service parts: Oversize [0.5 mm (0.020 in)]
PBIC3218J
PBIC3214J
EM-98
< UNIT DISASSEMBLY AND ASSEMBLY >
[MR20DD]
CYLINDER HEAD
d.
Using valve seat cutter set (commercial service tool) (A) or valve
seat grinder, finish valve seat to the specified dimensions. For
dimensions, refer to
CAUTION:
When using valve seat cutter, firmly grip the cutter handle
with both hands. Then, press on the contacting surface all
around the circumference to cut in a single drive. Improper
pressure on with the cutter or cutting many different times
may result in stage valve seat.
e.
Using compound, grind to adjust valve fitting.
f.
Check again for normal contact. Refer to
3.
Install valve oil seal.
• Install with a valve oil seal drift [SST: KV10115600]
to match
dimension in the figure.
NOTE:
Dimension is height that measured before installing valve
spring (with valve spring seat).
4.
Install valve.
• Install larger diameter to intake side.
5.
Install valve spring (with valve spring seat).
• Install smaller pitch (valve spring seat side) to cylinder head
side .
• Confirm identification color
of valve spring.
6.
Install valve spring retainer.
7.
Install valve collet.
• Compress valve spring with the valve spring compressor [SST:
KV10116200] (A), the attachment [SST: KV10115900] (C), and
the adapter [SST: KV10109220] (B). Install valve collet with a
magnet hand.
CAUTION:
• Be careful not to damage valve lifter holes.
JSBIA2471ZZ
Height (H)
: 15.1 - 15.7 mm (0.594 - 0.618 in)
PBIC3211J
: Valve spring seat (Do not remove from valve spring.)
Intake
: White
Exhaust
: Orange
JPBIA4479ZZ
JPBIA0180ZZ
CYLINDER HEAD
EM-99
< UNIT DISASSEMBLY AND ASSEMBLY >
[MR20DD]
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• Fit the attachment [SST: KV10115900 (J-26336-20)]
in
thecenter of valve spring retainer
to press it.
• Tap valve stem edge lightly with a plastic hammer after instal-
lation to check its installed condition.
8.
Install valve lifter.
• Install it in the original position.
9.
Install spark plug with spark plug wrench (commercial service tool).
Inspection
INFOID:0000000010783728
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 a 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 checked. Refer to
.
1.
Wipe off engine oil and remove water scale (like deposit), gasket, sealant, carbon, etc. with a scraper.
CAUTION:
Never allow gasket debris to enter passages for engine oil or water.
2.
At each of several locations on bottom surface of cylinder head,
measure the distortion in six directions using straightedge (A)
and feeler gauge (B).
• If it exceeds the limit, replace cylinder head.
INSPECTION AFTER DISASSEMBLY
VALVE DIMENSIONS
• Check the dimensions of each valve. For the dimensions, refer to
• If dimensions are out of the standard, replace valve and check valve seat contact. Refer to "VALVE SEAT
CONTACT".
VALVE GUIDE CLEARANCE
JPBIA4477ZZ
Limit [(d1) – (d2)]: 0.15 mm (0.0059 in)
PBIC3994E
Limit: Refer to
JSBIA2474ZZ
EM-100
< UNIT DISASSEMBLY AND ASSEMBLY >
[MR20DD]
CYLINDER HEAD
Valve Stem Diameter
• Measure the diameter of valve stem with micrometer (B).
Valve Guide Inner Diameter
• Measure the inner diameter of valve guide with bore gauge (A).
Valve Guide Clearance
• (Valve guide clearance) = (Valve guide inner diameter) – (Valve
stem diameter)
• If the calculated value exceeds the limit, replace valve and/or valve guide. When valve guide must be
EM-94, "Disassembly and Assembly"
.
VALVE SEAT CONTACT
• After confirming that the dimensions of valve guides and valves are within the specifications, perform this
procedure.
• Apply prussian blue (or white lead) onto contacting surface of valve seat to check the condition of the valve
contact on the surface.
• 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 recheck, replace
valve seat. Refer to
EM-94, "Disassembly and Assembly"
VALVE SPRING SQUARENESS
• Set a try square (A) along the side of valve spring and rotate
spring. Measure the maximum clearance
between the top of
spring and try square.
• If it exceeds the limit, replace valve spring.
VALVE SPRING DIMENSIONS AND VALVE SPRING PRESSURE LOAD
• Check valve spring pressure with valve spring seat installed at the
specified spring height.
CAUTION:
Never remove valve spring seat from valve spring.
• If the installation load or load with valve open is out of the stan-
dard, replace valve spring (with valve spring seat).
Standard and Limit: Refer to
JSBIA2475ZZ
: OK
JPBIA0187ZZ
: Contact
C
: V-block
Limit
: Refer to
JSBIA4163ZZ
Standard
: Refer to
SEM113
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