engine NISSAN PICK-UP 1998 Repair Manual

Valve Oil Seal
1. Remove rocker cover.
2. Remove rocker shaft assembly. (Refer to ``Disassembly'',
``CYLINDER HEAD'', EM-27.)
3. Remove valve spring and valve oil seal with Tool or suitable
tool.
lPiston concerned should be set at TDC to prevent valve
from falling.
4. Apply engine oil to new valve oil seal and install it with Tool.
lBefore installing valve oil seal, install valve spring seat.
Front Oil Seal
1. Remove radiator shroud and crankshaft pulley.
2. Remove front oil seal.
lBe careful not to scratch front cover.
3. Apply engine oil to new oil seal and install it using suitable
tool.
lInstall new oil seal in the direction shown.
SEM396EA
SEM822F
.Unit: mm (in)
AEM258
SEM715A
OIL SEAL REPLACEMENTKA
EM-22

Rear Oil Seal
1. Remove flywheel.
2. Remove rear oil seal retainer.
3. Remove rear oil seal from retainer.
lBe careful not to scratch rear oil seal retainer.
4. Apply engine oil to new oil seal and install it using suitable
tool.
lInstall new oil seal in the direction shown.
5. Install rear oil seal retainer.
a. Before installing rear oil seal retainer, remove all traces of
liquid gasket from mating surface using a scraper.
lAlso remove traces of liquid gasket from mating surface
of cylinder block.
b. Apply a continuous bead of liquid gasket to mating surface
of rear oil seal retainer.
lUse Genuine Liquid Gasket or equivalent.
lApply around inner side of bolt holes.
SEM895A
SEM715A
SEM897A
SEM896A
SEM085E
OIL SEAL REPLACEMENTKA
EM-23

CAUTION:
lWhen installing rocker arms, camshaft and oil seal, lubri-
cate contacting surfaces with new engine oil.
lWhen tightening cylinder head bolts and rocker shaft
bolts, lubricate bolt threads and seat surfaces with new
engine oil.
lHydraulic valve lifters are installed in each rocker arm.
If hydraulic valve lifter is kept on its side, even when
installed in rocker arm, there is a risk of air entering it.
When rocker arms are removed, stand them straight up
or soak them in new engine oil.
lDo not disassemble hydraulic valve lifter.
lAttach tags to valve lifters so as not to mix them up.
Removal
1. Release fuel pressure. Refer to EC section (``Fuel Pressure
Release'').
2. Drain coolant from radiator and drain plug of block.
3. Remove the following parts.
lPower steering drive belt
lPower steering pump, idler pulley and power steering brack-
ets
lVacuum hoses of swirl control valve and pressure control
solenoid valve
lAccelerator wire bracket
4. Remove bolts which hold intake manifold collector to intake
manifold.
5. Remove bolts which hold intake manifold to cylinder head
while raising collector upwards.
6. Remove exhaust manifold cover and exhaust manifold.
7. Remove rocker cover.
lWhen removing rocker cover, do not hit rocker cover
against rocker arm.
8. Set No. 1 piston at TDC on its compression stroke.
SEM878BA
SEM868BA
.NG
SEM216C
CYLINDER HEADKA
Rear Oil Seal
EM-25

Assembly
1. Install valve component parts.
lAlways use new valve oil seal. Refer to OIL SEAL
REPLACEMENT.
lBefore installing valve oil seal, install inner valve spring
seat.
lInstall outer valve spring (uneven pitch type) with its
narrow pitch side toward cylinder head side.
lAfter installing valve component parts, use plastic ham-
mer to lightly tap valve stem tip to assure a proper fit.
2. Install camshaft, placing knock pin towards front of engine
and in the top position.
lApply engine oil to camshaft when mounting onto cylin-
der head.
3. Install camshaft brackets.
lFront mark is punched on the camshaft bracket.
Location (from front side)Identification
Mark Punched
No. 1 51 Ð
No. 2 52 2
No. 3 53 Ð
No. 4 52 4
No. 5 55 Ð
4. Install rocker shaft with rocker arms.
lInstall retainer with cutout facing direction shown in figure at
left.
SEM638B
SEM236C
SEM606F
SEM399E
SEM274C
CYLINDER HEADKA
EM-33

3. Set chain on camshaft sprocket by aligning each mating
mark. Then install camshaft sprocket to camshaft.
4. Tighten camshaft sprocket bolt.
5. Install rubber plugs. Refer to TIMING CHAIN, EM-21.
6. Check hydraulic valve lifter.
a. Push hydraulic valve lifter forcefully with your finger.
lBe sure to check it with rocker arm in its free position.
b. If valve lifter moves more than 1 mm (0.04 in), air may be
inside of it.
c. Bleed air off by running engine at 1,000 rpm under no-load
for about 20 minutes.
d. If hydraulic valve lifters are still noisy, replace them and bleed
air off again in the same manner as in step c.
7. Install rocker cover. Refer to TIMING CHAIN, EM-21.
lBe sure to avoid interference between rocker cover and
rocker arm.
8. Install intake and exhaust manifolds. Refer to ``OUTER COM-
PONENT PARTS'', EM-9.
SEM612F
SEM592F
SEM275C
CYLINDER HEADKA
Installation (Cont'd)
EM-35

WARNING:
lPosition vehicle on a flat and solid surface.
lPlace chocks at front and back of rear wheels.
lDo not remove engine until exhaust system has com-
pletely cooled off.
Otherwise, you may burn yourself and/or fire may break
out in fuel line.
lBefore disconnecting fuel hose, release fuel pressure.
Refer to EC section (``Fuel Pressure Release'').
lBe sure to hoist engine and transmission in a safe man-
ner.
lFor engines not equipped with engine slingers, attach
proper slingers and bolts described in PARTS CATA-
LOG.
CAUTION:
lWhen lifting engine, be sure to clear surrounding parts.
Take special care near accelerator wire casing, brake
lines and brake master cylinder.
lIn lifting the engine, always use engine slingers in a safe
manner.
lFor 4WD models, apply sealant between engine and
transmission. Refer to MT section (``Removal and Instal-
lation'').
SEM601FA
ENGINE REMOVALKA
EM-36

Removal
1. Drain coolant from engine block and radiator. Refer to MA
section (``Changing Engine Coolant'', ``ENGINE MAINTE-
NANCE'').
2. Release fuel pressure. Refer to EC section (``Fuel Pressure
Release'').
3. Remove negative battery cable.
4. Remove hood. Refer to BT section.
5. Remove power steering drive belt, alternator drive belt and
A/C compressor drive belt.
6. Remove radiator. Refer to LC section (``Radiator'', ``ENGINE
COOLING SYSTEM'').
7. Remove exhaust manifold heat shield.
8. Disconnect exhaust system from exhaust manifold.
9. Discharge refrigerant. Refer to HA section (``R-134a Service
Procedure'', ``SERVICE PROCEDURES'').
10. Disconnect refrigerant lines. Refer to HA section (``Refriger-
ant Lines'', ``SERVICE PROCEDURES'').
11. Disconnect accelerator wire, vacuum hoses, electrical
connectors, heater hoses and vacuum booster hose.
12. Remove four power steering pump bolts.
13. Remove transmission. Refer to MT section (``Removal'',
``REMOVAL AND INSTALLATION'').
14. Remove LH and RH engine mounts.
15. Remove engine.
Installation
lInstall in reverse order of removal.
SEM602F
SEM603F
SEM604F
ENGINE REMOVALKA
EM-37

CAUTION:
lWhen installing sliding parts (bearings, pistons, etc.),
lubricate contacting surfaces with new engine oil.
lPlace removed parts such as bearings and bearing caps
in their proper order and direction.
lWhen installing connecting rod nuts and main bearing
cap bolts, apply new engine oil to threads and seating
surfaces.
lDo not allow any magnetic materials to contact the ring
gear teeth of flywheel or drive plate.
Disassembly
PISTON AND CRANKSHAFT
1. Remove intake manifold.
2. Place engine on a work stand.
3. Drain coolant and oil.
4. Remove oil pan.
5. Remove water pump.
6. Remove timing chain.
7. Remove cylinder head.
8. Remove pistons with connecting rod.
9. Remove bearing caps and crankshaft.
lBefore removing bearing caps, measure crankshaft end
play. Refer to EM-47.
lBolts should be loosened in two or three steps.
Inspection
PISTON AND PISTON PIN CLEARANCE
1. Measure inner diameter of piston pin hole ``dp''.
Standard diameter ``dp'':
21.002 - 21.008 mm (0.8268 - 0.8271 in)
2. Measure outer diameter of piston pin ``Dp''.
Standard diameter ``Dp'':
20.993 - 20.998 mm (0.8265 - 0.8267 in)
3. Calculate piston pin clearance.
dp þ Dp = 0.008 - 0.012 mm (0.0003 - 0.0005 in)
If it exceeds the above value, replace piston assembly with
pin.
SEM744-A
EEM118
AEM023
AEM024
CYLINDER BLOCKKA
EM-39

2. Set piston rings as shown.
CAUTION:
lWhen piston rings are not replaced, make sure that pis-
ton rings are mounted in their original positions.
lWhen piston rings are being replaced and no punchmark
is present, piston rings can be mounted with either side
up.
3. Align piston rings so that end gaps are positioned as shown.
CRANKSHAFT
1. Set main bearings in their proper positions on cylinder block
and main bearing caps.
lConfirm that correct main bearings are used. Refer to
EM-42.
lApply new engine oil to bearing surfaces.
2. Install crankshaft and main bearing caps and tighten bolts to
the specified torque.
lApply new engine oil to the bolt threads and seat sur-
face.
lPrior to tightening bearing cap bolts, place bearing cap
in its proper position by shifting crankshaft in the axial
direction.
lTighten bearing cap bolts gradually in two or three
stages. Start with center bearing and move outward as
shown in figure.
lAfter securing bearing cap bolts, make sure crankshaft
turns smoothly by hand.
SEM215EA
SEM264C
SEM160B
SEM448C
EEM121
CYLINDER BLOCKKA
Assembly (Cont'd)
EM-46

3. Measure crankshaft end play.
Crankshaft end play: mm (in)
Standard
0.05 - 0.18 (0.0020 - 0.0071)
Limit
0.3 (0.012)
If beyond the limit, replace bearing with a new one.
4. Install connecting rod bearings in connecting rods and con-
necting rod caps.
lConfirm that correct bearings are used.
Refer to EM-45.
lInstall bearings so that oil hole in connecting rod aligns
with oil hole of bearing.
lApply new engine oil to bearing surfaces, bolt threads
and seating surfaces.
5. Install pistons with connecting rods.
a. Install them into corresponding cylinders with Tool.
lArrange so that front mark on piston head faces toward
front of engine.
lMake sure connecting rod does not scratch cylinder
wall.
lMake sure connecting rod bolts do not scratch crank-
shaft journals.
lApply new engine oil to piston rings and sliding surface
of piston.
b. Install connecting rod bearing caps.
Tighten connecting rod bearing cap nuts using the following
procedure.
Connecting rod bearing nut:
(1) Tighten to 14 to 16 N´m
(1.4 to 1.6 kg-m, 10 to 12 ft-lb).
(2) Tighten bolts 60
+5
þ0degrees clockwise
with an angle wrench.
If an angle wrench is not available, tighten
them to 38 to 44 N´m (3.9 to 4.5 kg-m, 28 to 33
ft-lb).
6. Measure connecting rod side clearance.
Connecting rod side clearance: mm (in)
Standard
0.2 - 0.4 (0.008 - 0.016)
Limit
0.6 (0.024)
If beyond the limit, replace connecting rod and/or crankshaft.
EEM122
SEM159B
SEM269CA
EEM123
EEM124
CYLINDER BLOCKKA
Assembly (Cont'd)
EM-47