Service Limit.............0.15 mm (0.006 in.)
Valve Guide
Overall Length±Intake........44mm(1.732 in.)
Overall Length±Exhaust.......48mm(1.889 in.)
Outside Diameter...........13.055 - 13.065 mm
(0.514 - 0.5143 in.)
Inside Diameter..............8.000 - 8.018 mm
(0.314 - 315 in.)
Valve Springs
Free Length (Approx.).......49.8 mm (1.960 in.)
Service Limit............48.8 mm (1.9213 in.)
Loaded Height...............40.4 mm @ 33 kg
(1.59 in. @73 lbs.)
Perpendicularity±Intake and Exhaust . . .2É (Max.)
Service Limit.....................4É(Max.)
Oil Pump
Clearance Over Rotors (Max.) .0.077 mm (0.003 in.)
Cover Out-of-Flat (Max.).....0.076 mm (0.003 in.)
Inner Rotor Thickness (Min.) .18.92 mm (0.744 in.)
Outer Rotor (Oil Pump)
Clearance (Max.)...........0.19 mm (0.007 in.)
Diameter (Min.)...........82.45 mm (3.246 in.)
Thickness (Min.)...........18.92 mm (0.744 in.)
Tip Clearance Between Rotors (Max.) . . .0.150 mm
(0.0068 in.)
Oil Pressure
At Curb Idle Speed*...........68.9 kPa (10 psi)
At 3000 rpm.........310 - 517 kPa (45 - 75 psi)
CAUTION: * If pressure is ZERO at curb Idle, DO
NOT run engine at 3,000 rpm.
TORQUE CHART 3.0L
DESCRIPTION TORQUE
Camshaft Bearing Cap
Bolts. . .Refer to procedure outlined in this section.
Camshaft Sensor Pick Up
Bolts.....................27N´m(20ft.lbs.)
Timing Belt Cover
Outer to Inner Attaching Bolts..........4.5 N´m
(40 in. lbs.)
Inner Cover to Head/Oil Pump Bolts.....12N´m
(105 in. lbs.)
Camshaft Sprocket
Bolt......................95N´m(70ft.lbs.)
Connecting Rod Cap
Bolts..........27N´m(20ft.lbs.) Plus 1/4 Turn
Crankshaft Main Bearing Cap/Bedplate
M8 Bedplate Bolts.........34N´m(250 in. lbs.)
M11 Main Cap Bolts..................41N´m
(30 ft. lbs.) Plus 1/4 Turn
Crankshaft Vibration Damper
Bolt....................135 N´m (100 ft. lbs.)DESCRIPTION TORQUE
Cylinder Head
Bolts........Refer To Cylinder Head Installation
Cylinder Head Cover
Bolts....................12N´m(105 in. lbs.)
Engine Mount Bracket
Bolts.....................41N´m(30ft.lbs.)
Engine MountÐFront and Rear
Through Bolt...............61N´m(45ft.lbs.)
Exhaust Manifold to Cylinder Head
Bolts....................23N´m(200 in. lbs.)
Exhaust Manifold Heat Shield
Bolts....................12N´m(105 in. lbs.)
Intake Manifold
Bolts.....................27N´m(20ft.lbs.)
Oil Filter to Engine Block Adapter
Bolts.....................55N´m(40ft.lbs.)
Oil Filter
Filter.....................20N´m(15ft.lbs.)
Oil Pan
Oil Pan Bolts.............12N´m(105 in. lbs.)
Drain Plug.................39N´m(29ft.lbs.)
Oil Pump Attaching
Bolts....................15N´m(130 in. lbs.)
Oil Pump Cover Fastener.....9N´m(104 in. lbs.)
Oil Pump Pick-up Tube Bolt . .28 N´m (250 in. lbs.)
Oil Pump Relief Valve Cap. . . .49 N´m (36 ft. lbs.)
Spark Plugs
Plugs.....................28N´m(20ft.lbs.)
Thermostat Housing
Bolts....................23N´m(200 in lbs.)
Timing Belt Tensioner
Bolt......................28N´m(20ft.lbs.)
Timing Belt Tensioner Pulley Assembly
Bolt......................41N´m(30ft.lbs.)
Water Pump Mounting
Bolts....................12N´m(105 in. lbs.)
9 - 90 3.0L ENGINENS
SPECIFICATIONS (Continued)
SPECIAL TOOLS
3.0L ENGINE
Dolly 6135
Cradle 6710
Adaptor 6909
Adaptor 6910
Camshaft End Plug Installer MD-998306
Valve Stem Seal Installer MD-998729
Rear Crankshaft Seal Installer MD-998718
NS3.0L ENGINE 9 - 91
Front Crankshaft Seal Installer MD-998717
Oil Filter Wrench C-4065
Spanner Camshaft Sprocket MB-990775
9 - 92 3.0L ENGINENS
SPECIAL TOOLS (Continued)
3.3/3.8L ENGINE
INDEX
page page
DESCRIPTION AND OPERATION
ENGINE COMPONENTS.................. 93
ENGINE IDENTIFICATION................. 93
ENGINE LUBRICATION SYSTEM............ 93
DIAGNOSIS AND TESTING
CHECKING ENGINE OIL PRESSURE......... 96
HYDRAULIC TAPPETS.................... 94
SERVICE PROCEDURES
CRANKSHAFT END PLAY................. 99
FITTING CONNECTING ROD BEARINGS...... 97
FITTING MAIN BEARINGS................. 98
FITTING PISTONS AND RINGS............. 97
MEASURING TIMING CHAIN FOR STRETCH . . . 96
VALVE SERVICE RECONDITION........... 100
VALVE TIMING.......................... 96
REMOVAL AND INSTALLATION
CAMSHAFT BEARINGS.................. 114
CAMSHAFT........................... 113
CRANKSHAFT DAMPER................. 106
CRANKSHAFT OIL SEALÐFRONT.......... 117
CRANKSHAFT OIL SEALÐREAR........... 118
CRANKSHAFT......................... 116
CYLINDER HEAD COVER................ 107
CYLINDER HEAD....................... 108
ENGINE ASSEMBLY..................... 104
ENGINE MOUNTS...................... 102
ENGINE OIL GALLERY PLUGS............. 119OILFILTER ............................ 119
OILPAN .............................. 114
PISTON AND CONNECTING ROD.......... 115
ROCKER ARMS AND SHAFT ASSEMBLY..... 106
TAPPET REMOVAL...................... 110
TIMING CHAIN COVER................... 111
TIMING CHAIN......................... 112
VALVE STEM SEALS OR SPRINGS,
CYLINDER HEAD NOT REMOVED........ 106
VALVES AND VALVE SPRINGS............ 109
WIPER UNIT.......................... 102
DISASSEMBLY AND ASSEMBLY
HYDRAULIC TAPPETS................... 120
OIL PUMP............................ 119
CLEANING AND INSPECTION
CYLINDER HEAD....................... 120
ENGINE BLOCK AND BORE............... 121
OILPAN .............................. 121
OIL PUMP............................ 121
ADJUSTMENTS
ENGINE MOUNTS...................... 123
SPECIFICATIONS
3.3/3.8L ENGINE....................... 123
TORQUE CHART....................... 125
SPECIAL TOOLS
3.3/3.8L ENGINE....................... 127
DESCRIPTION AND OPERATION
ENGINE IDENTIFICATION
The engine identification number is located on the
rear of the cylinder block just below the cylinder
head (Fig. 1).
ENGINE LUBRICATION SYSTEM
The lubrication system is a full flow filtration pres-
sure feed type. Oil from the oil pan is pumped by a
internal gear type oil pump directly coupled to the
crankshaft. The pressure is regulated by a relief
valve located in the chain case cover. The oil is
pumped through an oil filter and feeds a main oil
galley. This oil gallery feeds oil under pressure to the
main and rod bearings, camshaft bearings. Passages
in the cylinder block feed oil to the hydraulic lifters
and rocker shaft brackets which feeds the rocker arm
pivots (Fig. 2).
ENGINE COMPONENTS
ENGINE:The 3.3L (201 Cubic Inches) and 3.8L
(231 Cubic Inches) displacement engines are 60É V
type six cylinder power plants with cast iron cylinder
blocks and aluminum cylinder heads (Fig. 3). Firing
order for these engines is 1-2-3-4-5-6. High turbu-
lence cylinder heads allow a 8.9-1 compression ratio.
CRANKSHAFT:The nodular iron crankshaft is
supported by four main bearings, with number two
being the thrust bearing. Crankshaft end sealing is
provided by front and rear rubber seals.
PISTONS:The pistons are cast aluminum alloy.
Three rings are used. Piston pins, press fitted into
place, join the pistons to forged steel connecting rods.
CAMSHAFT:The nodular iron camshaft is
mounted in four steel backed babbitt bearings. A
thrust plate located in front of the first bearing, and
bolted to the block, controls end play. Silent timing
chain drives the camshaft. This chain is enclosed by
a cast aluminum cover which also carries a front
NS3.3/3.8L ENGINE 9 - 93
crankshaft seal, provides front oil pan closure, water
pump mounting.
CYLINDER HEADS:Cylinder heads are designed
to create high flow combustion chambers to improve
performance, while minimizing the change to the
burn rate of the chamber. Valve seat and guides are
inserts. A steel flanged composition type gasket is
used between head and block.
CYLINDER HEAD COVERS:The covers are
sealed with steel reinforced silicon rubber gaskets.INTAKE MANIFOLD:The intake manifold is a
tuned two-piece semi-permanent mold aluminum
casting with individual primary runners leading from
a plenum to the cylinders. The manifold is designed
to boost torque in the 3600 rpm range and contrib-
utes to the engine's broad, flat torque curve, which
was desired for excellent engine tractability, response
and usable power output.
The intake manifold is also cored with upper level
EGR passages for balanced cylinder to cylinder EGR
distribution.
VALVE TRAIN:Valve train design incorporates
the use of hydraulic roller tappets. Rocker arms are
installed on a rocker arm shaft attached to the cylin-
der head with four bolts and retainers. Viton valve
stem seals provide valve sealing. Conventional type
pushrods, retainers and valve stem locks are used.
Unique beehive style valve spring are used with
lightweight retainers for improved high RPM perfor-
mance.
EXHAUST MANIFOLDS:Exhaust manifolds are
log type with a crossover and is attached directly to
the cylinder heads.
DIAGNOSIS AND TESTING
HYDRAULIC TAPPETS
The valve train includes roller tappet assemblies,
aligning yokes and yoke retainer.
Roller tappet alignment is maintained by machined
flats on tappet body being fitted in pairs into six
Fig. 2 Engine Oiling System
Fig. 1 Engine Identification
9 - 94 3.3/3.8L ENGINENS
DESCRIPTION AND OPERATION (Continued)
aligning yokes. The yokes are secured by an align-
ment yoke retainer (Fig. 4).
PRELIMINARY STEP TO CHECKING THE
HYDRAULIC TAPPETS
Before disassembling any part of the engine to cor-
rect tappet noise, read the oil pressure at the gauge.
Install a reliable gauge at pressure sending unit if
vehicle has no oil pressure gauge and check the oil
level in the oil pan. The pressure should be between
30 and 80 psi (206.8 to 551.6 kPa) at 2000 rpm.
The oil level in the pan should never be above the
MAX mark on dipstick, or below the MIN mark.
Either of these two conditions could be responsible
for noisy tappets.Oil Level Check: stop engineafter reaching normal operating temperature.
Allow 5 minutes to stabilize oil level, check dipstick.
OIL LEVEL TOO HIGH
If oil level is above the MAX mark on dip stick, it
is possible for the connecting rods to dip into the oil
while engine is running and create foam. Foam in oil
pan would be fed to the hydraulic tappets by the oil
pump causing them to become soft and allow valves
to seat noisily.
OIL LEVEL TOO LOW
Low oil level may allow pump to take in air which
when fed to the tappets, causes them to become soft
and allows valves to seat noisily. Any leaks on intake
side of pump through which air can be drawn will
create the same tappet action. Check the lubrication
system from the intake strainer to the pump cover,
including the relief valve retainer cap. When tappet
noise is due to aeration, it may be intermittent or
constant, and usually more than one tappet will be
noisy. When oil level and leaks have been corrected,
engine should be operated at fast idle to allow all of
the air inside of the tappets to be bled out.
VALVE TRAIN NOISE DIAGNOSIS
To determine source of valve train noise, operate
engine at idle with cylinder head covers removed and
listen for source of the noise.
Fig. 3 3.3/3.8L V-6 Engines
Fig. 4 Roller Tappets Aligning Yoke and Retainer
NS3.3/3.8L ENGINE 9 - 95
DIAGNOSIS AND TESTING (Continued)
NOTE: Worn valve guides or cocked springs are
sometimes mistaken for noisy tappets. If such is
the case, noise may be dampened by applying side
thrust on the valve spring. If noise is not apprecia-
bly reduced, it can be assumed the noise is in the
tappet. Inspect the rocker arm push rod sockets
and push rod ends for wear.
Valve tappet noise ranges from light noise to a
heavy click. A light noise is usually caused by exces-
sive leak-down around the unit plunger which will
necessitate replacing the tappet, or by the plunger
partially sticking in the tappet body cylinder. A heavy
click is caused either by a tappet check valve not
seating, or by foreign particles becoming wedged
between the plunger and the tappet body causing the
plunger to stick in the down position. This heavy
click will be accompanied by excessive clearance
between the valve stem and rocker arm as valve
closes. In either case, tappet assembly should be
removed for inspection and cleaning.
CHECKING ENGINE OIL PRESSURE
Check oil pressure using gauge at oil pressure
switch location. Oil pressure should be 34.47 kPa (5
psi.) at idle or 205 to 551 kPa (30 to 80 psi.) at 3000
RPM.
(1) Remove pressure sending unit and install oil
pressure gauge (Fig. 5).
CAUTION: If oil pressure is 0 at idle, do not run
engine at 3000 RPM.
(2) Warm engine at high idle until thermostat
opens.
SERVICE PROCEDURES
VALVE TIMING
(1) Remove front cylinder head cover and all 6
spark plugs.
(2) Rotate engine until the #2 piston is at TDC of
the compression stroke.
(3) Install a degree wheel on the crankshaft pulley.
(4) With proper adaptor, install a dial indicator
into #2 spark plug hole. Using the indicator find TDC
on the compression stroke.
(5) Position the degree wheel to zero.
(6) Remove dial indicator from spark plug hole.
(7) Place a 5.08 mm (0.200 in.) spacer between the
valve stem tip of #2 intake valve and rocker arm pad.
Allow tappet to bleed down to give a solid tappet
effect.
(8) Install a dial indicator so plunger contacts the
#2 intake valve spring retainer as nearly perpendic-
ular as possible. Zero the indicator.
(9) Rotate the engine clockwise until the intake
valve has lifted .254 mm (0.010 in.).
CAUTION: Do not turn crankshaft any further
clockwise as intake valve might bottom and result
in serious damage.
(10) Degree wheel should read 6 degrees BTDC to
6 degrees ATDC.
MEASURING TIMING CHAIN FOR STRETCH
(1) Place a scale next to timing chain so that any
movement of chain may be measured.
(2) Place a torque wrench and socket on camshaft
sprocket attaching bolt and apply torque in direction
of crankshaft rotation to take up slack; 41 N´m (30 ft.
lb.) with cylinder head installed or 20 N´m (15 ft. lb.)
with cylinder heads removed.With a torque
applied to the camshaft sprocket bolt, crank-
shaft should not be permitted to move. It may
be necessary to block crankshaft to prevent
rotation.
(3) Holding a scale even, with dimension reading
as shown (Fig. 6), along edge of chain links. Apply
torque in the reverse direction to 41 N´m (30 ft. lbs.)
with cylinder heads installed, or 20 N´m (15 ft. lbs.)
with cylinder heads removed. Check amount of chain
movement.
(4) Install a new timing chain, if its movement
exceeds 3.175 mm (1/8 inch).
(5) If chain is not satisfactory, refer to Timing
Chain Removal and Installation in this section.
Fig. 5 Checking Oil Pump Pressure
9 - 96 3.3/3.8L ENGINENS
DIAGNOSIS AND TESTING (Continued)
FITTING PISTONS AND RINGS
FITTING PISTONS
The piston and cylinder wall must be clean and
dry. Piston diameter should be measured 90 degrees
to piston pin at size location shown in (Fig. 8). Cyl-
inder bores should be measured halfway down the
cylinder bore and transverse to the engine crankshaft
center line shown in (Fig. 7). Refer to Cylinder Bore
and Piston Specification Chart.Pistons and cylin-
der bores should be measured at normal room
temperature, 70ÉF (21ÉC).
FITTING RINGS
(1) Wipe cylinder bore clean. Insert ring and push
down with piston to ensure it is square in bore. Thering gap measurement must be made with the ring
positioning at least 12 mm (0.50 in.) from bottom of
cylinder bore. Check gap with feeler gauge (Fig. 9).
Refer to Piston Ring Specification Chart.
(2) Check piston ring to groove clearance: (Fig. 10).
Refer to Piston Ring Specification Chart.
FITTING CONNECTING ROD BEARINGS
Fit all rods on one bank until complete.
The bearing caps are not interchangeable and
should be marked at removal to insure correct
assembly.
The bearing shells must be installed with the
tangs inserted into the machined grooves in the rods
and caps. Install cap with the tangs on the same side
as the rod.
Limits of taper or out-of-round on any crankshaft
journals should be held to 0.025 mm (0.001 in.).
Bearings are available in 0.025 mm (0.001 in.) and
0.250 mm (0.010 in.) undersize.Install the bear-
ings in pairs. Do not use a new bearing half
Fig. 6 Measuring Timing Chain Wear and Stretch
Fig. 7 Checking Cylinder Bore Size
CYLINDER BORE AND PISTON
SPECIFICATION CHART
EngineStandard
BoreMaximum
Out-Of-
RoundMaximum
Taper
3.3L 92.993 -
93.007 mm0.076 mm 0.51 mm
(3.661 -
3.6617 in.)(0.003 in.) (0.002 in.)
3.8L 95.993 -
96.007 mmSame Same
3.7792 -
3.780 in.
Standard Piston Size
3.3L 92.950 - 92.968 mm (3.6594 - 3.6602 in.)
3.8L 95.950 - 95.968 mm (3.7776 - 3.7783 in.)
Piston to Bore Clearance: 0.025 - 0.057 mm
(0.0009 - 0.0022 in.)
Measurements taken at Piston Size Location.
Fig. 8 Piston Measurements
NS3.3/3.8L ENGINE 9 - 97
SERVICE PROCEDURES (Continued)