1999 NISSAN PICK-UP Repair Manual

VALVE OIL SEAL
1. Remove rocker cover.
2. Remove camshaft. Refer to ªTIMING CHAINº (EM-2013).
3. Remove valve spring and valve oil seal with Tool or a suit-
able tool.
Piston 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.
OIL SEAL INSTALLING DIRECTION
lInstall new oil seal in the direction shown.
FRONT OIL SEAL
1. Remove radiator shroud and crankshaft pulley.
2. Remove front oil seal.
lBe careful not to scratch front cover.
SEM289DB
SEM290D
SEM715A
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OIL SEAL REPLACEMENTKA24DE
EM-2021

3. Apply engine oil to new oil seal and install it using a suitable
tool.
REAR OIL SEAL
1. Remove flywheel or drive plate.
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.
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SEM895A
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OIL SEAL REPLACEMENTKA24DE
EM-2022

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.
AEM404
OIL SEAL REPLACEMENTKA24DE
EM-2023

V1Oil filler cap
V2Rocker cover
V3Camshaft bracket
V4Intake camshaft
V5Exhaust camshaft
V6Shim
V7Valve lifter
V8Valve cotter
V9Spring retainer
V10Valve spring
V11Spring seat
V12Valve oil seal
V13Intake valve
V14Exhaust valve
V15Cylinder head
V16Cylinder head bolt
SEM996F
CYLINDER HEADKA24DE
EM-2024

CAUTION:
lWhen installing camshafts, chain tensioners, oil seals,
or other sliding parts, lubricate contacting surfaces with
new engine oil.
lApply new engine oil to threads and seat surfaces when
installing cylinder head, camshaft sprocket, crankshaft
pulley, and camshaft bracket.
lAttach tags to valve lifters so as not to mix them up.
lBefore removing camshaft and idler sprockets, apply
paint marks to them for retiming.
Removal
1. Drain coolant from radiator and cylinder block. Refer to MA
section (ªChanging Engine Coolantº, ªENGINE MAINTE-
NANCEº).
2. Remove upper timing chain and idler sprocket.
lRefer to ªUPPER TIMING CHAINº (EM-2015) and ªIDLER
SPROCKETº (EM-2016), ªRemovalº, ªTIMING CHAINº.
lFor retiming during cylinder head removal/installation,
apply paint marks to camshaft sprockets, upper timing
chain, lower timing chain and idler sprocket.
3. Remove camshaft brackets and camshafts.
lMark the original positions of these parts for reassem-
bly.
4. Remove cylinder head bolts in numerical order.
lRemoving bolts in incorrect order could result in a
warped or cracked cylinder head.
lLoosen cylinder head bolts in two or three steps.
5. Remove cylinder head and cylinder head gasket.
Installation
1. Tighten cylinder head bolts in numerical order using the fol-
lowing procedure:
a. Tighten all bolts to 29 Nzm (3.0 kg-m, 22 ft-lb).
b. Tighten all bolts to 79 Nzm (8.1 kg-m, 59 ft-lb).
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SEM274D
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CYLINDER HEADKA24DE
EM-2025

c. Loosen all bolts completely.
d. Tighten all bolts to 25 to 34 Nzm (2.5 to 3.5 kg-m, 18 to 25
ft-lb).
e. Turn all bolts 86 to 91É clockwise. If angle wrench is not
available, mark all cylinder head bolts on the side facing
engine front. Then, turn each cylinder head bolt 86 to 91É
clockwise.
2. Install camshafts and camshaft brackets in the order shown
using the following procedure:
a. Set camshafts and camshaft brackets.
b. Tighten all bolts to 2 Nzm (0.2 kg-m, 17 in-lb).
c. Tighten all bolts to 9.1 to 11.7 Nzm (0.92 to 1.2 kg-m, 80 to
104 in-lb).
lApply new engine oil to bolt threads and seat surfaces.
3. Install upper timing chain and idler sprocket.
lRefer to ªUPPER TIMING CHAINº (EM-2019) and ªIDLER
SPROCKETº (EM-2019), ªInstallationº, ªTIMING CHAINº.
4. Refill engine coolant. Refer to MA section (ªChanging Engine
Coolantº, ªENGINE MAINTENANCEº).
Disassembly
1. Remove intake manifold and exhaust manifold. Refer to
ªOUTER COMPONENT PARTSº (EM-2007).
2. Remove valve components.
3. Remove valve oil seal with a suitable tool.
Inspection
CYLINDER HEAD DISTORTION
Clean surface of cylinder head.
Use a reliable straightedge and feeler gauge to check the flat-
ness of cylinder head surface.
Check along six positions shown in the figure.
Head surface flatness:
Standard Less than 0.03 mm (0.0012 in)
Limit 0.1 mm (0.004 in)
If beyond the specified limit, replace it or resurface it.
Resurfacing limit:
SEM276D
SEM998F
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CYLINDER HEADKA24DE
Installation (Cont'd)
EM-2026

The limit of cylinder head resurfacing is determined by the
cylinder block resurfacing.
Amount of cylinder head resurfacing is ªAº.
Amount of cylinder block resurfacing is ªBº.
The maximum limit:
A+B=0.2mm(0.008 in)
After resurfacing cylinder head, check that camshaft rotates
freely by hand. If resistance is felt, cylinder head must be
replaced.
Nominal cylinder head height:
126.3 - 126.5 mm (4.972 - 4.980 in)
CAMSHAFT VISUAL CHECK
Check camshaft for scratches, seizure and wear.
CAMSHAFT RUNOUT
1. Measure camshaft runout at the center journal.
Runout (Total indicator reading):
Standard
Less than 0.02 mm (0.0008 in)
Limit
0.04 mm (0.0016 in)
2. If it exceeds the limit, replace camshaft.
CAMSHAFT CAM HEIGHT
1. Measure camshaft cam height.
Standard cam height:
Intake 42.505 - 42.695 mm (1.673 - 1.681 in)
Exhaust 40.905 - 41.095 mm (1.610 - 1.618 in)
Cam height wear limit:
Intake & Exhaust
0.2 mm (0.008 in)
2. If wear is beyond the limit, replace camshaft.
CAMSHAFT JOURNAL CLEARANCE
1. Install camshaft bracket and tighten bolts to the specified
torque.
2. Measure inner diameter of camshaft bearing.
Standard inner diameter:
#1 to #5 journals
28.000 - 28.025 mm (1.1024 - 1.1033 in)
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Inspection (Cont'd)
EM-2027

3. Measure outer diameter of camshaft journal.
Standard outer diameter:
#1 to #5 journals
27.935 - 27.955 mm (1.0998 - 1.1006 in)
4. If clearance exceeds the limit, replace camshaft and/or cyl-
inder head.
Camshaft journal clearance:
Standard 0.045 - 0.090 mm (0.0018 - 0.0035 in)
Limit 0.12 mm (0.0047 in)
CAMSHAFT END PLAY
1. Install camshaft in cylinder head.
2. Measure camshaft end play.
Camshaft end play:
Standard
0.070 - 0.148 mm (0.0028 - 0.0058 in)
Limit
0.2 mm (0.008 in)
3. If end play exceeds the limit, replace camshaft and remea-
sure camshaft end play.
4. If end play still exceeds the limit after replacing camshaft,
replace cylinder head.
CAMSHAFT SPROCKET RUNOUT
1. Install sprocket on camshaft.
2. Measure camshaft sprocket runout.
Runout (Total indicator reading):
Limit 0.15 mm (0.0059 in)
3. If it exceeds the limit, replace camshaft sprocket.
VALVE GUIDE CLEARANCE
1. Measure valve deflection as shown in figure. (Valve and
valve guide mostly wear in this direction.)
Valve deflection limit (Dial gauge reading):
Intake & Exhaust
0.2 mm (0.008 in)
SEM012A
SEM296D
AEM328
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CYLINDER HEADKA24DE
Inspection (Cont'd)
EM-2028