engine NISSAN PATROL 1998 Y61 / 5.G Engine Mechanical User Guide

CAUTION:
+Do not bend or twist timing belt.
+After removing timing belt, do not turn crankshaft and
camshaft separately because valves will strike piston
heads.
+Make sure that timing belt, camshaft sprocket, crankshaft
sprocket, idler pulley, injection pump pulley and belt ten-
sioner are clean and free from oil and water.
+Align white lines on timing belt with punch mark on cam-
shaft sprocket, crankshaft sprocket and injection pump
pulley.
+Installation should be carried out when engine is cold.
Removal
1. Remove radiator shroud.
2. Remove the following belts.
+Power steering drive belt
+A/C compressor drive belt
+Alternator drive belt
3. Remove cooling fan coupling and water pump pulley.
SMA767BA
TIMING BELT
EM-16

Inspection
Visually check the condition of timing belt.
Replace if any abnormality is found.
Item to check Problem Cause
Tooth is broken/tooth root
is cracked.
SEM394A
+Camshaft jamming
+Distributor jamming
+Damaged camshaft/crankshaft oil seal
Back surface is cracked/
worn.
SEM395A
+Tensioner jamming
+Overheated engine
+Interference with belt cover
Side surface is worn.
+Belt corners are worn and round.
+Wicks are frayed and coming out.
SEM396A
+Improper installation of belt
+Malfunctioning crankshaft pulley plate/timing belt
plate
Teeth are worn.
+Canvas on tooth face is worn down.
+Canvas on tooth is ¯uffy, rubber layer is worn
down and faded white, or weft is worn down and
invisible.
SEM397A
+Poor belt cover sealing
+Coolant leakage at water pump
+Camshaft not functioning properly
+Distributor not functioning properly
+Excessive belt tension
Oil/Coolant or water is
stuck to belt. Ð+Poor oil sealing of each oil seal
+Coolant leakage at water pump
+Poor belt cover sealing
TIMING BELT
EM-18

CAMSHAFT AND CRANKSHAFT OIL SEAL INSTALLING
DIRECTION AND MANNER
+When installing camshaft and crankshaft oil seals, be care-
ful to install them correctly, as shown in the ®gure.
+Apply engine oil to oil seal lip, outer face, camshaft and
bracket.
+Wipe off excess oil after installing oil seal.
CAMSHAFT OIL SEALS
1. Remove timing belts, sprockets and back covers.
2. Pull out oil seal with a suitable tool.
3. Install new oil seals with a suitable tool.
CRANKSHAFT FRONT OIL SEAL
1. Remove valve timing belt and crankshaft sprocket.
2. Remove oil pan and oil pan gasket.
3. Remove oil pump assembly.
4. Remove front oil seal with a suitable tool.
5. Apply engine oil to new oil seal and install oil seal using a suit-
able tool.
SEM715A
SEM743B
SEM733B
SEM893A
SEM894A
OIL SEAL REPLACEMENT
EM-22

CRANKSHAFT REAR OIL SEAL
1. Remove transmission assembly. (Refer to ``REMOVAL AND
INSTALLATION'' in MT section.)
2. Remove clutch cover assembly.
3. Remove ¯ywheel and rear plate.
4. Remove oil pan and oil pan gasket.
5. Remove oil seal retainer assembly.
6. Remove traces of liquid gasket using a scraper.
7. Remove rear oil seal from retainer.
8. Apply engine oil to new oil seal and install oil seal using a suit-
able tool.
9. Apply a continuous bead of liquid gasket to rear oil seal
retainer.
a. Coat of liquid gasket should be maintained within 2.0 to 3.0
mm (0.079 to 0.118 in) dia. range.
b. Attach oil seal retainer to cylinder block within ®ve min-
utes after coating.
c. Wait at least 30 minutes before re®lling engine oil or start-
ing engine.
d. Use Genuine Liquid Gasket or equivalent.
SEM896A
SEM895A
SEM897A
SLC822
SEM144B
OIL SEAL REPLACEMENT
EM-23

Removal and Installation
1. Drain engine coolant.
2. Remove the following:
+Air duct and hoses
+Air intake pipe
+EGR pipe
+Heat shield plates
+Intake manifold
+Front (exhaust) tube
+Oil tube and water tube
3. Remove exhaust manifold with turbocharger from cylinder
head.
4. When installing turbocharger to exhaust manifold, securely
tighten nuts and lock the nuts.
+Turbocharger should not be disassembled.
SEM784F
TURBOCHARGER
EM-24

CAUTION:
+When installing sliding parts such as camshaft and oil
seal, be sure to apply new engine oil on their sliding sur-
faces.
+When tightening cylinder head bolts, apply new engine oil
to thread portions and seat surfaces of bolts.
Removal
1. Remove charge air cooler assembly.
2. Set No. 1 cylinder at BDC on its expansion stroke.
3. Drain engine coolant from drain plugs on cylinder block and
radiator.
4. Remove air cleaner and/or air duct.
5. Remove timing belt.
6. Remove rocker cover securing bolts/nuts in numerical order
shown in ®gure.
To install rocker cover, tighten bolts/nuts in reverse order of
removal. Tighten in two or three stages.
7. Remove camshaft sprocket, injection pump drive sprocket and
back cover.
8. Disconnect exhaust manifold from exhaust tube.
9. Remove intake and exhaust manifold.
To install manifolds, tighten bolts/nuts in reverse order of
removal. Tighten in two or three stages.
SEM786F
SEM711B
SEM431C
CYLINDER HEAD
EM-30

10. Remove fuel injection tube assembly and spill tube.
11. Remove cylinder head bolts in numerical order and remove
cylinder head.
Disassembly
1. Remove following parts:
a. Thermostat housing
b. Engine slinger
c. Glow plate and glow plugs
2. Remove camshaft bracket securing nuts in numerical order
shown in ®gure in two or three stages.
To install camshaft bracket caps, tighten nuts in reverse order
of removal. Tighten in two or three stages.
3. Remove camshaft and oil seal.
4. Remove valve lifters.
5. Remove valve component parts with tool.
SEM703B
SEM714B
SEM716B
CYLINDER HEAD
Removal (Cont'd)
EM-31

Inspection
CYLINDER HEAD DISTORTION
Warpage of surface:
Less than 0.1 mm (0.004 in)
If beyond the speci®ed limit, replace it or resurface it.
Resurfacing limit:
The resurfacing limit of cylinder head is determined by the
cylinder block resurfacing in an engine.
Amount of cylinder head resurfacing is ``A''.
Amount of cylinder block resurfacing is ``B''.
The maximum limit is as follows:
A + B = 0.1 mm (0.004 in)
Nominal cylinder head height:
139.9 - 140.1 mm (5.508 - 5.516 in)
VALVE GUIDE CLEARANCE
1. Insert the valve stem into the valve guide and move it back,
forth and slide it.
If valve stem makes a clatter and moves back and forth exces-
sively out of line, or if it does not slide well, replace valve or
valve guide, or both.
2. Install valve stem into the valve guide.
3. Measure the de¯ection.
Stem to guide de¯ection limit:
0.1 mm (0.004 in)
(Half of dial gauge reading)
4. If it exceeds the limit, check valve to valve guide clearance.
(1) Measure valve stem diameter and guide inner diameter.
(2) Check that clearance is within the speci®cation.
Valve to valve guide clearance limit:
0.1 mm (0.004 in)
(3) If it exceeds the limit, replace valve or valve guide.
VALVE GUIDE REPLACEMENT
1. Heat cylinder head 150 to 160ÉC (302 to 320ÉF) in oil.
2. Remove the guide with suitable tool.
SEM718B
SEM719B
EM030
SEM871
CYLINDER HEAD
EM-32

VALVE LIFTER
1. Check contact and sliding surfaces for wear or scratches.
2. Check diameter of a valve lifter.
Outer diameter:
34.960 - 34.975 mm (1.3764 - 1.3770 in)
3. Check valve lifter guide bore.
Bore diameter:
34.998 - 35.018 mm (1.3779 - 1.3787 in)
Standard clearance:
0.023 - 0.058 mm (0.0009 - 0.0023 in)
If valve lifters are noisy, check valve lifter.
(1) Depress plunger forcibly with your ®nger.
If it moves about 1 mm (0.04 in), it indicates air is inside valve lifter.
(2) Reinstall valve lifter.
(3) Bleed air by running engine at 2,400 rpm under no-load for
about 20 minutes.
CAUTION:
When camshaft is removed to install, remove or inspect
hydraulic valve lifters, do not start engine for at least 30 min-
utes after reinstalling camshaft. (Wait until hydraulic valve lift-
ers have reached their set lengths.) Before starting engine,
rotate crankshaft by hand to ensure pistons do not interfere
with valves.
(4) Next check to ensure all air is bled. [Refer to step (1) above.]
(5) If there is still air, replace valve lifter.
SEM723B
SEM724B
SEM725B
CYLINDER HEAD
Inspection (Cont'd)
EM-36

Assembly
1. Install valve component parts.
Install valve spring with its narrow pitch side toward cylinder
head side.
a. When installing valve, apply engine oil on the valve stem
and lip of valve oil seal.
b. Check whether the valve face is free from foreign matter.
c. Install valve spring retainers on the intake side and valve
rotators on the exhaust side.
d. Valve rotators cannot be disassembled.
2. Set camshaft.
Set camshaft so that dowel pin faces up.
3. Install cam bracket caps so that front mark faces forward.
Cam bracket nut (Tighten in two or three stages):
:21-26Nzm
(2.1 - 2.7 kg-m, 15 - 20 ft-lb)
4. Apply engine oil to new oil seal and install it.
Installation
1. Install cylinder head gasket.
a. When replacing only cylinder head gasket, install same
grade gasket as the one formerly used.
b. When replacing or repairing cylinder block, cylinder head,
piston, connecting rod and crankshaft, select gasket as
follows:
SEM202
SEM731BB
SEM732B
SEM733B
CYLINDER HEAD
EM-38