(3) Before removing valves,remove any burrs
from valve stem lock grooves to prevent dam-
age to the valve guides.Identify valves to insure
installation in original location.
VALVE INSTALLATION
(1) Coat valve stems with clean engine oil and
insert them in cylinder head.
(2) Check valve tip to spring seat dimensions A
after grinding the valve seats or faces. Grind valve
tip to give 49.541 to 51.271 mm (1.950 to 2.018 in.)
over spring seat when installed in the head (Fig. 41).
Check valve tip for scoring, if necessary, the tip
chamfer should be reground to prevent seal damage
when the valve is installed.
(3) Install valve spring seat spacer on head (Fig.
42).
(4) Install new cup seals on all valve stems and
over valve guides (Fig. 41). Install valve springs and
valve retainers (Fig. 42).
(5) Compress valve springs with Valve Spring
Compressor Tool C-3422-B, with adapter 6412 install
locks and release tool.If valves and/or seats are
reground, measure the installed height of
springs dimension B, make sure measurementsare taken from top of spring seat to the bottom
surface of spring retainer. If height is greater
than 1-19/32 inches, (40.6 mm), install a 1/32
inch (.794 mm) spacer in head counterbore to
bring spring height back to normal 1-17/32 to
1-19/32 inch (39.1 to 40.6 mm).TAPPET REMOVAL
(1) Refer to Cylinder Head Removal in this section.
Cylinder Head must be removed to gain access to
tappets for service.
(2) Remove yoke retainer and aligning yokes.
(3) Use Tool C-4129 to remove tappets from their
bores. If all tappets are to be removed, identify tap-
pets to insure installation in original location.
NOTE: If the tappet or bore in cylinder block is
scored, scuffed, or shows signs of sticking, ream
the bore to next oversize and replace with oversize
tappet.
CAUTION: The plunger and tappet bodies are not
interchangeable. The plunger and valve must
always be fitted to the original body. It is advisable
to work on one tappet at a time to avoid mixing of
parts. Mixed parts are not compatible. Do not disas-
semble a tappet on a dirty work bench.
INSTALLATION
(1) Lubricate tappets.
(2) Install tappets in their original positions.
(3) With roller tappets, install aligning yokes (Fig.
43).
(4) Install yoke retainer and torque screws to 12
N´m (105 in. lbs.) (Fig. 43).
(5) Install cylinder heads. Refer to cylinder head
installation of this section for procedure.
Fig. 40 Compress Valve Springs with Special Tool
C-3422-B with Adapter 6412
Fig. 41 Checking Valve Installed Height
Fig. 42 Valve Seal and SpringÐInstallation
9 - 110 3.3/3.8L ENGINENS
REMOVAL AND INSTALLATION (Continued)
(6) Tap the piston down in cylinder bore, using a
hammer handle. At the same time, guide connecting
rod into position on connecting rod journal.
(7) The notch or groove on top of piston must be
pointing toward front of engine (Fig. 60).
(8) Install rod caps. Install nuts on cleaned and
oiled rod bolts and tighten nuts to 54 N´m (40 ft. lb.)
Plus 1/4 turn.
(9) Repeat procedure for each piston and rod
installation.
(10) Install cylinder heads and oil pan.
(11) Fill engine crankcase with proper oil to cor-
rect level.
(12) Connect negative cable to battery.
CRANKSHAFT
MAIN BEARINGS
Bearing caps are not interchangeable and should
be marked at removal to insure correct assembly
(Fig. 62). Upper and lower bearing halves are NOT
interchangeable. Lower main bearing halves of 1, 3
and 4 are interchangeable. Upper main bearing
halves of 1, 3 and 4 are interchangeable.
CRANKSHAFT MAIN JOURNALS
The crankshaft journals should be checked for
excessive wear, taper and scoring. (Fig. 61) Limits of
taper or out-of-round on any crankshaft journals
should be held to 0.025 mm (0.001 in.). Journal
grinding should not exceed 0.305 mm (0.012 in.)
under the standard journal diameter. Do NOT grind
thrust faces of Number 2 main bearing. Do NOT nick
crank pin or bearing fillets. After grinding, remove
rough edges from crankshaft oil holes and clean out
all passages.
CAUTION: With the nodular cast iron crankshafts
used it is important that the final paper or cloth pol-ish after any journal regrind be in the same direc-
tion as normal rotation in the engine.
Upper and lower Number 2 bearing halves are
flanged to carry the crankshaft thrust loads and are
NOT interchangeable with any other bearing halves
in the engine (Fig. 63). All bearing cap bolts removed
during service procedures are to be cleaned and oiled
before installation. Bearing shells are available in
standard and the following undersizes: 0.025 mm
(0.001 in.) and 0.254 mm (0.010 in). Never install an
undersize bearing that will reduce clearance below
specifications.
REMOVAL
(1) Remove oil pan and identify bearing caps
before removal.
(2) Remove bearing caps one at a time. Remove
upper half of bearing by inserting Special Main Bear-
ing Tool C-3059. (Fig. 64) into the oil hole of crank-
shaft.
Fig. 60 Piston I.D. NotchesFig. 61 Measure Crankshaft Journal O.D.
Fig. 62 Main Bearing Cap Identification
9 - 116 3.3/3.8L ENGINENS
REMOVAL AND INSTALLATION (Continued)
Install new gasket and tighten screws to 12 N´m (105
in. lbs.).
OIL FILTER
CAUTION: When servicing the oil filter (Fig. 71)
avoid deforming the filter can by installing the
remove/install tool band strap against the can-to-
base lock seam. The lock seam joining the can to
the base is reinforced by the base plate.
(1) Using Tool C-4065, turn filter counterclockwise
to remove from base. Properly discard filter.
(2) Wipe base clean, then inspect gasket contact
surface.
(3) Lubricate gasket of new filter with clean
engine oil.
(4) Install new filter until gasket contacts base.
Tighten filter 1 turn or 20 N´m (15 ft. lbs.). Use filter
wrench if necessary.
(5) Start engine and check for leaks.
ENGINE OIL GALLERY PLUGS
REMOVAL
Using a blunt tool such as a drift and a hammer,
strike the bottom edge of the cup plug. With the cup
plug rotated, grasp firmly with pliers or other suit-
able tool and remove plug (Fig. 72).CAUTION: Do not drive cup plug into the casting
as restricted cooling can result and cause serious
engine problems.
INSTALLATION
Thoroughly clean inside of cup plug hole in cylin-
der block or head. Be sure to remove old sealer.
Lightly coat inside of cup plug hole with Loctite Stud
N' Bearing Mount or equivalent. Make certain the
new plug is cleaned of all oil or grease. Using proper
drive plug, drive plug into hole so that the sharp
edge of the plug is at least 0.5 mm (0.020 in.) inside
the lead-in chamfer.
DISASSEMBLY AND ASSEMBLY
OIL PUMP
It is necessary to remove the oil pan, oil pickup
and chain case cover to service the oil pump rotors.
The oil pump pressure relief valve can be serviced by
removing the oil pan and oil pickup tube. Refer to
Timing Chain Cover Removal and Installation of this
section for procedures.
DISASSEMBLY
(1) To remove the relief valve, proceed as follows:
Fig. 70 Rear Crankshaft Oil SealÐInstallation
Fig. 71 Oil Filter
Fig. 72 Core Hole Plug Removal
NS3.3/3.8L ENGINE 9 - 119
REMOVAL AND INSTALLATION (Continued)
(2) Drill a 3.175 mm (1/8 inch) hole into the relief
valve retainer cap and insert a self-threading sheet
metal screw into cap.
(3) Clamp screw into a vise and while supporting
chain case cover, remove cap by tapping chain case
cover using a soft hammer. Discard retainer cap and
remove spring and relief valve (Fig. 73).
(4) Remove oil pump cover screws, and lift off
cover.
(5) Remove pump rotors.
(6) Wash all parts in a suitable solvent and inspect
carefully for damage or wear (Fig. 76).
OIL PUMP ASSEMBLY
(1) Assemble pump, using new parts as required.
Install the inner rotor with chamfer facing the
cast iron oil pump cover.
(2) Tighten cover screws to 12 N´m (105 in. lbs.).
(3) Prime oil pump before installation by filling
rotor cavity with engine oil.
(4) Install chain case cover. Refer to Timing Chain
Cover Installation of this section.
HYDRAULIC TAPPETS
DISASSEMBLY
(1) Pry out plunger retainer spring clip (Fig. 74).
(2) Clean varnish deposits from inside of tappet
body above plunger cap.
(3) Invert tappet body and remove plunger cap,
plunger, flat or ball check valve, check valve spring,
check valve retainer and plunger spring. Check valve
could be flat or ball.
ASSEMBLY
(1) Clean all tappet parts in a solvent that will
remove all varnish and carbon.
(2) Replace tappets that are unfit for further ser-
vice with new assemblies.(3) If plunger shows signs of scoring or wear, valve
is pitted, or valve seat on end of plunger indicates
any condition that would prevent valve from seating,
install a new tappet assembly.
(4) Assemble tappets (Fig. 74).
CLEANING AND INSPECTION
CYLINDER HEAD
(1) Before cleaning, check for leaks, damage and
cracks.
(2) Clean cylinder head and oil passages.
(3) Check cylinder head for flatness (Fig. 75).
(4) Inspect all surfaces with a straightedge if there
is any reason to suspect leakage. If out of flatness
exceeds 0.019 mm (0.00075 in.) times the span length
in inches, in any direction, either replace head or
lightly machine the head surface. As an example, if a
12 inch span is 0.1 mm (.004 in.) out of flat, allow-
able is 12 x .019 mm (.00075 in.) equals .22 mm (.009
in.) This amount of out of flat is acceptable. Maxi-
mum of 0.2 mm (.008 in.) for grinding is permitted.
CAUTION: This is a combined total dimension of
stock removal from cylinder head and block top
surface.
Fig. 73 Oil Pressure Relief Valve
Fig. 74 Hydraulic Roller Tappet Assembly
Fig. 75 Check Cylinder Head
9 - 120 3.3/3.8L ENGINENS
DISASSEMBLY AND ASSEMBLY (Continued)
OIL PAN
(1) Clean oil pan in solvent and wipe dry with a
clean cloth. Clean all gasket material from mounting
surfaces of pan and block.
(2) Inspect oil drain plug and plug hole for
stripped or damaged threads and repair as necessary.
Install a new drain plug gasket. Tighten to 27 N´m
(20 ft. lbs.).
(3) Inspect oil pan mounting flange for bends or
distortion. Straighten flange if necessary.
(4) Clean oil screen and pipe in clean solvent.
Inspect condition of screen.
OIL PUMP
INSPECTION AND REPAIR
(1) Clean all parts thoroughly. Mating surface of
the chain case cover should be smooth. Replace pump
cover if scratched or grooved.
(2) Lay a straightedge across the pump cover sur-
face (Fig. 77). If a 0.025 mm (0.001 in.) feeler gauge
can be inserted between cover and straight edge,
cover should be replaced.
(3) Measure thickness and diameter of outer rotor.
If outer rotor thickness measures 7.64 mm (0.301 in.)
or less (Fig. 78), or if the diameter is 79.95 mm
(3.148 inches.) or less, replace outer rotor.
(4) If inner rotor measures 7.64 mm (0.301 in.) or
less replace inner rotor (Fig. 79).
(5) Slide outer rotor into chain case cover, press to
one side with fingers and measure clearance between
rotor and chain case cover (Fig. 80). If measurement
is 0.39 mm (0.015 in.) or more, replace CCC only if
outer rotor is in specification.
(6) Install inner rotor into chain case cover. If
clearance between inner and outer rotors (Fig. 81) is
0.203 mm (0.008 in.) or more, replace both rotors.
(7) Place a straightedge across the face of the
chain case cover, between bolt holes. If a feeler gaugeof 0.10 mm (0.004 in.) or more can be inserted
between rotors and the straightedge, replace pump
assembly (Fig. 82).ONLYif rotors are in specs.
(8) Inspect oil pressure relief valve plunger for
scoring and free operation in its bore. Small marks
may be removed with 400-grit wet or dry sandpaper.
(9) The relief valve spring has a free length of
approximately 49.5 mm (1.95 inches) it should test
between 19.5 and 20.5 pounds when compressed to
34 mm (1-11/32 inches). Replace spring that fails to
meet specifications (Fig. 73).
(10) If oil pressure is low and pump is within spec-
ifications, inspect for worn engine bearings or other
reasons for oil pressure loss.
ENGINE BLOCK AND BORE
CLEANING AND INSPECTION
(1) Clean cylinder block thoroughly and check all
core hole plugs for evidence of leaking.
Fig. 76 Oil Pump
Fig. 77 Checking Oil Pump Cover Flatness
Fig. 78 Measuring Outer Rotor Thickness
NS3.3/3.8L ENGINE 9 - 121
CLEANING AND INSPECTION (Continued)
(2) If new core plugs are installed, see Engine Core
Oil and Cam Plugs.
(3) Examine block for cracks or fractures.
CYLINDER BORE INSPECTION
The cylinder walls should be checked for out-of-
round and taper with Tool C-119 (Fig. 83). If the cyl-
inder walls are badly scuffed or scored, the cylinder
block should be replaced.
Measure the cylinder bore at three levels in direc-
tions A and B (Fig. 83). Top measurement should be
12 mm (0.50 in.) down and bottom measurement
should be 12 mm (0.50 in.) up from bottom of bore.
Refer to Cylinder Bore and Piston Specification
Chart.
Fig. 79 Measuring Inner Rotor Thickness
Fig. 80 Measuring Outer Rotor Clearance in
Housing
Fig. 81 Measuring Clearance Between Rotors
Fig. 82 Measuring Clearance Over Rotors
Fig. 83 Checking Cylinder Bore Size
9 - 122 3.3/3.8L ENGINENS
CLEANING AND INSPECTION (Continued)
ENGINE
CONTENTS
page page
2.0L SOHC ENGINE...................... 12.5L VM DIESEL....................... 40
2.0L SOHC ENGINE
INDEX
page page
DESCRIPTION AND OPERATION
ENGINE COMPONENTS.................. 3
ENGINE IDENTIFICATION................. 1
ENGINE LUBRICATION SYSTEM............ 2
GENERAL SPECIFICATION................ 2
DIAGNOSIS AND TESTING
CHECKING ENGINE OIL PRESSURE........ 3
SERVICE PROCEDURES
CRANKSHAFT END PLAY................. 6
CYLINDER BORE AND PISTON SIZING....... 4
FITTING CONNECTING RODS.............. 5
FITTING CRANKSHAFT BEARINGS.......... 6
FITTING PISTON RINGS.................. 4
REMOVAL AND INSTALLATION
CAMSHAFT OIL SEAL................... 12
CAMSHAFT............................ 7
CRANKSHAFT OIL SEALÐREAR........... 20
CRANKSHAFT......................... 21
CYLINDER HEAD COVER................. 6
CYLINDER HEAD....................... 10
FRONT CRANKSHAFT OIL SEAL........... 18
OILFILTER ........................... 24
OIL FILTER ADAPTER................... 24OILPAN .............................. 17
OIL PUMP............................ 25
PISTON AND CONNECTING ROD.......... 25
ROCKER ARM/HYDRAULIC LASH ADJUSTER . . 8
SPARK PLUG TUBE...................... 7
TIMING BELT COVER................... 11
TIMING BELT SYSTEM.................. 13
VALVE SEALS AND SPRINGS IN VEHICLE . . . 10
VIBRATION DAMPER.................... 28
DISASSEMBLY AND ASSEMBLY
OIL PUMP............................ 29
VALVE SERVICE WITH THE CYLINDER HEAD
REMOVED.......................... 29
CLEANING AND INSPECTION
CYLINDER BLOCK AND BORE............ 34
CYLINDER HEAD AND CAMSHAFT
JOURNALS.......................... 32
OIL PUMP............................ 32
SPECIFICATIONS
ENGINE 2.0L SOHC..................... 34
TORQUE CHART 2.0L SOHC.............. 36
SPECIAL TOOLS
ENGINE 2.0L SOHC..................... 36
DESCRIPTION AND OPERATION
ENGINE IDENTIFICATION
The engine identification number is located on the
left rear of the cylinder block behind starter (Fig. 1).
Fig. 1 Engine Identification SOHC
NS/GSENGINE 9 - 1
SPLASH LUBRICATION
Oil returning to the pan from pressurized compo-
nents supplies lubrication to the valve stems. Cylin-
der bores and wrist pins are splash lubricated from
directed slots on the connecting rod thrust collars.
ENGINE COMPONENTS
CYLINDER BLOCK AND BEDPLATE ASSEM-
B LY:A partial open deck is used for cooling and
weight reduction with water pump molded into the
block. Nominal wall thickness is 4 mm. The bedplate
incorporates main bearing caps. Rear seal retainer is
integral with the block.
CRANKSHAFT:A nodular cast iron crankshaft is
used. The engine has 5 main bearings, with number
3 flanged to control thrust. The 52 mm diameter
main and 48 mm diameter crank pin journals (all)
have undercut fillet radiuses that are deep rolled for
added strength. To optimize bearing loading 8 coun-
terweights are used. Hydrodynamic seals provide end
sealing, where the crankshaft exits the block.
Anaerobic gasket material is used for parting line
sealing. A sintered iron timing belt sprocket is
mounted on the crankshaft nose. This sprocket trans-
mits crankshaft movement, via timing belt to the
camshaft sprocket providing timed valve actuation.
PISTONS:The SOHC EngineDOES NOThave
provision for a free wheeling valve train. Non free
wheeling valve train means, in the event of a broken
timing belt Pistons will contact the Valves. All
engines use pressed-in piston pins to attach forged
powdered metal connecting rods. The connecting rods
are a cracked cap design and are not repairable. Hexhead cap screw are used to provide alignment and
durability in the assembly. Pistons And Connecting
rods are serviced as an assembly.
PISTON RINGS:The piston rings include a
molybdenum faced top ring for reliable compression
sealing and a taper faced intermediate ring for addi-
tional cylinder pressure control. Oil Control Ring
Package consist of 2 steel rails and a expander
spacer.
CYLINDER HEADÐSOHC:It features a Single
Over Head Camshaft, four-valves per cylinder cross
flow design. The valves are arranged in two inline
banks, with the two intake per cylinder facing
toward the radiator. The exhaust valves facing
toward the dash panel. Rocker arm shafts mount
directly to the cylinder head. It incorporates powder
metal valve guides and seats. The hollow rocker arm
shafts supplies oil to the hydraulic lash adjusters,
camshaft and valve mechanisms.
CAMSHAFTÐSOHC:The nodular iron camshaft
has five bearing journals and 3 cam lobes per cylin-
der. Provision for cam position sensor on the cam at
the rear of cylinder head which also acts as thrust
plate. A hydrodynamic oil seal is used for oil control
at the front of the camshaft.
VALVESÐSOHC:Four valves per cylinder are
actuated by roller rocker arms/hydraulic lash adjust-
ers assemblies which pivot on rocker arm shafts. All
valves have 6 mm diameter chrome plated valve
stems. The valve train has 33 mm (1.299 inch) diam-
eter intake valves and 28 mm (1.10 inch) diameter
exhaust valves. Viton rubber valve stem seals are
integral with spring seats. Valve springs, spring
retainers, and locks are conventional design.
INTAKE MANIFOLD:The intake manifold is a
molded plastic composition, attached to the cylinder
head with ten fasteners. This long branch design
enhances low and mid-range torque.
EXHAUST MANIFOLD:The exhaust manifold is
made of nodular cast iron for strength and high tem-
peratures. Exhaust gasses exit through a machined,
articulated joint connection to the exhaust pipe.
DIAGNOSIS AND TESTING
CHECKING ENGINE OIL PRESSURE
(1) Remove oil pressure switch and install gauge
assembly C-3292 with adaptor.
(2) Run engine until thermostat opens.
CAUTION: If oil pressure is 0 at idle, Do Not per-
form the 3000 RPM test in the next step.
(3) Oil Pressure:Curb Idle25 kPa (4 psi) mini-
mum3000 RPM170-550 kPa (25-80 psi).
Fig. 2 Engine Lubrication SystemÐ SOHC
NS/GSENGINE 9 - 3
DESCRIPTION AND OPERATION (Continued)