1995 NISSAN ALMERA N15 Service Manual

OILSEAL REPLACEMENT

Install newvalve oilseals forNo.1 andNO.4 cylinders as
illustrated. Reinstallvalvesprings. (narrowpitchside
toward cylinder head)
Install valvespring retainers onintake valves andvalve
rotators onexhaust valves,andremount valveassembly.
Set NO.2 cylinder at
TOG.

Replace valveoilseals forNo.2 andNo.3 cylinders accord-
ing tosteps 2)and 3).
Install valvelifters inoriginal positions.
5.
Remove valveliftersandmark order No.oneach lifter.
6. Replace valveoilseal according tothe following procedure.

When replacing valveallseal, setthe corresponding pistonat
TOe. Failure todo socauses thevalve todrop intothecylin-
der.
1) Set NO.1 cylinder at
TOG.

2) Remove valvesprings andvalve oilseals forNO.1 andNo.
4 cylinders. Valvespring seatsshould notberemoved.

VALVE
OilSEAL

1. Remove bothtiming belts.
2. Remove camshaft sprockets andback covers.
3. Remove camshaft bracketsbyloosening bracketnutsfrom
center tooutside intwo orthree stages.
4. Remove camshaft oilseals andcamshaft.

3)

+0.3
15.2 -0.3
mm

(0598
+0.012
In)

4)

. -0.012

5)

6)
~ 7)
SEM512D
Engine
/'t

inside
Y
r-l'\.
Engine
LV outside CAMSHAFT
ANDCRANKSHAFT OilSEAL INSTALLING
DIRECTION ANDMANNER
• When installing camshaftandcrankshaft oilseals, becare-
ful toinstall themcorrectly, asshown inthe figure.
• Apply engine oiltooil seal lip,outer face,camshaft and
bracket. .
• Wipe offexcess allafter installing oilseal.
Oil seal lip Dust
seallip
SEM715A CAMSHAFT OilSEALS

1. Remove timingbelts,sprockets andback covers.
2. Pull outoilseal withasuitable tool.

EM-126

OILSEAL REPLACEMENT

3. Install newoilseals withasuitable tool.

Confirm turningdirection ofboth oilseals andcamshaft .

•

Rear
Front

SEM240D
CRANKSHAFT FRONTOILSEAL

1. Remove valvetiming beltandcrankshaft sprocket.
2. Remove oilseal withasuitable tool.
3. Apply engine oiltonew oilseal andinstall oilseal using a
suitable tool.

CRANKSHAFT REAROILSEAL

1. Remove transaxle assembly. (Referto"REMOVAL AND
INSTALLATION" in
MT
section.)
2. Remove flywheel.
3. Remove rearoilseal withasuitable tool.
4. Apply engine oiltonew oilseal andinstall oilseal using a
suitable tool.

EM-127

CYLINDERHEAD

SEC. 111-130-135

[O.J
87-107 (8.9 -10.9, 64-79)

/ Swirl chamber
(Combustion chamber)
Valve seat

[O.J
87•107 (8.9 -10.9, 64-79)

~ :N.m (kg-m, in-Ib)

[O.J :
N. m (kg-m, ft-Ib)

f] :
Lubricate withnewengine oil.
SEM226F

G)
Camshaft

@
Front oilseal

@
Collar

@
Grommet

@
Front backcover
@ Front camshaft sprocketplate

(J)
Front camshaft sprocket

@
Spring
@

Selective cylinderheadgasket

@)
Valve

@
Spring seat

@
Valve spring
@ Valve oilseal
@ Spring retainer (INT)/Valve
rotator (EXH)

@
Valve cotter
@

Hydraulic valvelifter
@ Rear backcover

@
Rear camshaft sprocket

@
Grommet

@)
Collar
@ Rocker covergasket

@
Cam bracket
@ Rear oilseal

For hydraulic valvelifter
• Before starting engine,makesurethatvalve doesnothitpiston whenrotating crankshaft byhand.
• When bleeding airout from hydraulic valvelifter,runengine atmore than2,400 rpmfor20minutes
or more.

EM-128

SEM373D
SEM682D SEM864
CYLINDER
HEAD

Removal

1. Drain coolant anddisconnect frontexhaust pipefrom man-
ifold.

2. Remove
waterhoses, airduct andintake manifold.

3. Remove
heatshield andexhaust manifold.

4. Remove
rocker
cover
andinjection tubes.

5. Remove
bothtiming belts.
Set NO.1 cylinder atTDC onitscompression stroke.Refer

to
"TIMING BELT"(EM-120).

After timing beltshavebeen removed, donot rotate crankshaft
and/or camshaft separately asvalves willhitpiston heads.
6. Remove
cylinderheadinnumerical orderasshown inthe
figure.

Disassembly
1. Remove frontcamshaft sprocketplate,frontandrear
sprockets usingspecial
service
toolorasuitable tool,and
front back
cover.
2. Remove
camshaft bracketsinorder fromoutside toinside.
• Loosen camshaft bracketnutsintwo orthree stages.

3. Remove
camshaft andoilseals.
•

SEM715B 4.
Remove valve
lifters.

For hydraulic valvelifter
• Do not sethydraulic valvelifters asillustrated asair will
enter valve liftercausing malfunction.
• Donot disassemble hydraulicvalvelifters.
• Attach tagstovalve lifters toprevent mixingthemup.
• Valve liftersmustbeput inengine oilafter removal.

5. Remove
valve
component partsusing special
service
tool
or asuitable tool.

• Keep eachvalve anditscomponents togetherandmark
them sothey canbereassembled intheir original positions.
EM-129

Warpageofsurface:
Less than0.1mm (0.004 in)

SEM595A

_ Mic~rmeter

..;- @f

l ~

--I\"
Y

'~~':-- +x

'~o
rA1-
Center

[gJ
Bottom
Valve guide Valve

SEM244D CYLINDER
HEAD
Disassembly (Cont'd)

6. Remove valveoilseals usingspecial tool.

Inspection
CYLINDER HEADDISTORTION

1. Visually checkforcracks anddeformation.
2. Check cylinder headfordistortion.

Head surface flatness:
Less than0.1mm (O.004 in)

If beyond thespecified limit,replace orresurface cylinder
head.

Resurfacing limit:
The resurfacing limitofthe cylinder headisrelated tothe
amount ofresurfacing ofthe cylinder block.
When:
"A"
isthe amount ofresurfacing neededforthe cylinder head
and
"8"
isthe amount ofresurfacing neededforthe cylinder
block, themaximum limitisdetermined by
A + 8= 0.1 mm (O.004 in)

After resurfacing cylinderhead,check thatcamshaft rotates
freely byhand. Ifresistance isfelt, thecylinder headmustbe
replaced.

Nominal heightofcylinder head:
137.9. 138.1mm(5.429 .5.437 in)
VALVE GUIDECLEARANCE

1. Measure deflection acrossthecylinder headasillustrated.

Valve deflection limit(dial gauge reading):
0.1 mm (0.004 in)

2. Ifexceeding thelimit, check valve-to-guide clearance.
a) Measure valvestemdiameter andvalve guide innerdiam-
eter asillustrated.
b) Check thatclearance iswithin thespecification .

Valve stemtovalve guide clearance limit:
0.1 mm (O.004 in)

c) Ifexceeding thelimit, replace valveorvalve guide.

EM-130

NGNG

SEM722BA CYLINDER
HEAD
[]Q]

Inspection (Cont'd)
VALVE GUIDEREPLACEMENT

1. Heat cylinder headinoil to150 to160°C (302to320°F).
2. Drive outvalve guide usingapress orhammer andasuit-
able tool.
3. Ream cylinder headvalve guide bore.

Reaming bore(service part):
11.185.11.196 mm(0.4404 .0.4408 in)

4. Heat cylinder headto150 to160°C (302to320°F) andpress
service valveguide ontocylinder head.
5. Ream valveguide.

Final size:
7.000 .7.015 mm(0.2756 .0.2762 in)
VALVE SEATS

1. Check valveandvalve seatforcontact.
Coat thevalve facewithprussian redlead.
If
contact is
wrong, correct valveseat.Ifthe valve redlead appears 360°
around face,thevalve stemandface areconcentric. Ifnot,
repair orreplace valve.
2. Check valveseats forpitting atcontact surface. Resurface
or replace ifexcessively worn.
Correct valveseatsurface.

When repairing valveseat,check valveandvalve guide for
wear beforehand. Ifworn, replace them.Thencorrect valve
seat.
EM-131
•

I

Recess
I
diameter

W: Refer toSOS.
I

SEM795A
SEMB76
SEM877
SEM635AA CYLINDER
HEAD
[£Q]

Inspection (Cont'd)
VALVE SEATREPLACEMENT

1. Bore outoldseat untilitcollapses.
Set machine depthstopsothat boring cannot contact bot-
tom face ofseat recess incylinder head.
2. Ream thecylinder headrecess.

Reaming boreforservice valveseat
[Oversize 0.5mm (0.020 in)]:
Intake 41.432 -41.454 mm(1.6312 -1.6320 in)
Exhaust 35.432-35.454 mm(1.3950 -1.3958 in)
Use thevalve gUide center forreaming toensure valveseatwill
have thecorrect fit.

3. Heat cylinder headtoatemperature of150 to160°C (302to
320°F) andpress fitseat untilitseats onthe bottom.
4. Install valveseats.

When replacing valveseat,valve should bereplaced aswell.

5. Cut orgrind valve seatusing asuitable toolatthe specified
dimensions asshown inSOS (EM-172).

The cutting shouldbedone withboth hands toobtain auniform
and concentric finish.

6. Apply asmall amount offine grinding compound tothe
valve's contacting faceandputthe valve intoitsguide.
Lap valve against itsseat untilproper valveseating is
obtained.
7. Check valveseating condition.

EM-132

T(Margin thickness)

II
~a
.
,

I
T(Th)

D

L
CYLINDER
HEAD @Q]
Inspection (Cont'd)
VALVE DIMENSIONS

1. Check dimensions ofeach valve. Fordimensions, referto
SDS (EM-171).
2. Correct orreplace anyvalve thatisfaulty .

d •

L-~
SEM188A

3.Valve faceorvalve stemendsurface shouldberefaced by
using avalve grinder.

When valveheadhasbeen worn down to0.5 mm (0.020 in)in
margin thickness, replacethevalve.
Grinding allowance torvalve stemtipis0.5 mm (0.020 in)or
less.
VALVE SPRING SQUARENESS

Check valvespring forsquareness usingasteel square andflat
surface plate.

If
spring isout ofsquare "S"more thanspecified limit,replace
with newone.

Out-at-square: OuterLess than2.1mm (0.083 in)
Inner less than1.9mm (0.075 in)

•
SEM333
VALVE SPRING PRESSURE LOAD

Measure thefree length andthetension ofeach spring. Ifthe
measured valueexceeds thespecified limit,replace spring.
Refer toSDS (EM-172).

EM113 HYDRAULIC VALVELIFTER

1. Check contact andsliding surfaces forwear orscratches .

SEM7238 EM-133