3.0L ENGINE
INDEX
page page
DESCRIPTION AND OPERATION
ENGINE COMPONENTS.................. 61
ENGINE IDENTIFICATION NUMBER......... 61
ENGINE LUBRICATION................... 61
DIAGNOSIS AND TESTING
CHECKING ENGINE OIL PRESSURE......... 62
SERVICE PROCEDURES
AUTO LASH ADJUSTER................... 62
CHECKING CRANKSHAFT END PLAY........ 65
FITTING CONNECTING ROD BEARINGS...... 63
FITTING MAIN BEARING.................. 63
VALVE SERVICE RECONDITION............ 66
REMOVAL AND INSTALLATION
CAMSHAFT SEAL....................... 72
CAMSHAFT............................ 71
CRANKSHAFT.......................... 81
CYLINDER HEAD COVER................. 70
CYLINDER HEAD........................ 73
ENGINE ASSEMBLY...................... 69
ENGINE MOUNTS....................... 68
FRONT CRANKSHAFT OIL SEAL............ 83OIL FILTER AND ADAPTOR................ 84
OILPAN ............................... 77
OIL PUMP............................. 84
PISTON AND CONNECTING ROD........... 78
REAR CRANKSHAFT SEAL................ 83
ROCKER ARMS......................... 72
TIMING BELT........................... 75
DISASSEMBLY AND ASSEMBLY
ROCKER ARMS AND SHAFTS.............. 85
CLEANING AND INSPECTION
CYLINDER BORE........................ 87
CYLINDER HEAD........................ 86
OIL PUMP............................. 87
TIMING BELT........................... 86
ADJUSTMENTS
ENGINE MOUNTS....................... 88
SPECIFICATIONS
3.0L ENGINE........................... 89
TORQUE CHART 3.0L.................... 90
SPECIAL TOOLS
3.0L ENGINE........................... 91
DESCRIPTION AND OPERATION
ENGINE IDENTIFICATION NUMBER
The engine identification number is located on the
rear of the cylinder block just below the cylinder
head (Fig. 1).
ENGINE LUBRICATION
System is a full flow filtration, pressure feed type.
The oil pump is mounted behind the timing belt
cover. The pump inner rotor is driven by the crank-
shaft. The engine oil pan contains a baffle plate to
control oil level fluctuation during engine operation.
ENGINE COMPONENTS
BLOCK:The cylinder block is a light weight
design created by reducing thickness in many parts
and a short 10 mm (3/8 in.) block skirt. High rigidity
is provided with ribs cast in the outer wall, a full
length water jacket, and a mono-block or beam type,
main bearing cap. This single unit four bearing cap
is designed to control vibration of the cylinder block
partition walls.
CRANKSHAFT:A six throw, five weight crank-
shaft is supported by four main bearings with num-
ber three being the thrust bearing. The six separate
connecting rod throws pins reduce torque fluctua-tions while a torsional vibration damper is used to
control torsion caused vibration of the crankshaft.
Rubber lipped seals are used at front and rear. The
Fig. 1 Engine Identification
NS3.0L ENGINE 9 - 61
front seal is retained in the oil pump case and the
rear is retained in a block-mounted housing.
PISTONS:Are aluminum alloy with a steel strut,
short height, and thin wall so as to be autothermic
and light weight. The piston head with valve
recesses, in combination with the cylinder head,
forms a compact spherical head with clearance for
total valve lift with pistons at top dead center. The
piston skirt, top and second ring lands are finished to
a tapered roughness for oil retention and high resis-
tance to scuffing. Piston pins, pressed into place, join
the pistons to the connecting rods.
CYLINDER HEAD:The alloy cylinder heads fea-
ture cross-flow type intake and exhaust ports. Valve
guides and inserts are hardened cast iron. Valves of
heat resistance steel are arranged in a V with each
camshaft on center. To improve combustion speed the
chambers are a compact spherical design with a
squish area of approximately 30 percent of the piston
top area. The cylinder heads are common to either
cylinder bank by reversing the direction of installa-
tion.
CAMSHAFTS:Two overhead camshafts provide
valve actuation, one front (radiator side of cylinder
bank) and one rear. The front camshaft is provided
with a distributor drive and is longer. Both cam-
shafts are supported by four bearing journals, thrust
for the front camshaft is taken at journal two and
the rear at journal three. Front and rear camshaft
driving sprockets are interchangeable. The sprockets
and the engine water pump are driven by a single
notched timing belt.
ROCKER ARM SHAFTS:The shafts are retained
by the camshaft bearing journal caps. Four shafts are
used, one for each intake and exhaust rocker arm
assembly on each cylinder head. The hollow shafts
provide a duct for lubricating oil flow from the cylin-
der head to the valve mechanisms.
ROCKER ARMS:Are of light weight die-cast with
roller type follower operating against the cam shaft.
The valve actuating end of the rocker arms are
machined to retain hydraulic lash adjusters, elimi-
nating valve lash adjustment.
VALVES:Are made of heat resistant steel, valve
springs are especially designed to be short. The valve
spring wire cross-section is oval shaped and provides
the same spring tension as longer springs. Valve
spring retainers, locks and seals are conventional.
INTAKE MANIFOLD:The aluminum alloy mani-
fold is a cross type with long runners to improve
inertia. The runners, attaching below at the cylinder
head, also attach above and support an air plenum.
The air plenum chamber absorbs air pulsations cre-
ated during the suction phase of each cylinder.
EXHAUST MANIFOLDS:Both manifolds are a
log style made of ductile cast iron. Exhaust gasses,collected from the front cylinder bank, leave the front
manifold through an end outlet and are fed through
an upper crossover tube to the rear manifold. The
collected exhaust from both manifolds are combined,
and exit to the exhaust pipe through an articulated
joint.
DIAGNOSIS AND TESTING
CHECKING ENGINE OIL PRESSURE
Check oil pressure using gauge at oil pressure
switch location. Oil pressure should be 41 kPa ( 6
psi.) at idle or 241 to 517 kPa (35 to 75 psi.) at 3000
RPM.
(1) Remove pressure sending unit and install oil
pressure gauge. (Fig. 2).
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
AUTO LASH ADJUSTER
The automatic lash adjusters are precision units
installed in machined openings in the valve actuating
ends of the rocker arms. Do not disassemble the auto
lash adjuster.
FUNCTION CHECK
Check auto adjusters for free play by inserting a
small wire through the air bleed hole in the rocker
arm andvery lightlypushing the auto adjuster ball
check down (Fig. 3). While lightly holding the check
ball down move the rocker up and down to check for
free play. If there is no play replace the adjuster.
Fig. 2 Checking Engine Oil Pressure
9 - 62 3.0L ENGINENS
DESCRIPTION AND OPERATION (Continued)
FITTING CONNECTING ROD BEARINGS
CONNECTING ROD CLEARANCE
(1) Following procedures specified in the Standard
Service Procedures Section for Measuring Main Bear-
ing Clearance and Connecting Rod Bearing Clear-
ance (Fig. 4). Refer to Connecting Rod Specification
Chart.
(2) Tighten nuts to 52 N´m (38 ft. lbs.).
(3) Remove connecting rod cap and measure Plas-
tigage (Fig. 4).
CAUTION: Do not rotate crankshaft or the Plasti-
gage may be smeared.
CONNECTING ROD SIDE CLEARANCE
Using a feeler gauge, check connecting rod side
clearance (Fig. 5). Refer to Connecting Rod Specifica-
tion Chart.
FITTING MAIN BEARING
INSPECTION
Visually check the main and connecting rod bear-
ing journals for wear, scuffs or scoring and replace if
necessary.
CRANKSHAFT OIL CLEARANCEÐ
MECHANICAL MEASUREMENT
Measure the journal outside diameter and the
main bearing inside diameter (Fig. 6) & (Fig. 7). If
the clearance exceeds the specifications limit, replace
the main bearing(s) and if necessary replace the
crankshaft. Refer to Crankshaft Clearance Specifica-
tion Chart.
PLASTIGAGE MEASUREMENT
(1) Remove oil from journal and bearing shell.
(2) Install crankshaft.
(3) Cut plastigage to same length as width of the
bearing and place it in parallel with the journal axis
(Fig. 8).
Fig. 3 Auto Lash AdjusterÐFunction Check
Fig. 4 Connecting RodÐChecking Bearing
Clearance
Fig. 5 Checking Connecting Rod Side Clearance
CONNECTING ROD SPECIFICATION CHART
Connecting Rod Bearing Oil Clearance
New Part: 0.018 - 0.036 mm
(0.0007 - 0.0014 in.)
Connecting Rod Side Clearance
New Part: 0.10 - 0.25 mm
(0.004 - 0.010 in.)
Wear Limit: 0.4 mm (0.015 in.)
NS3.0L ENGINE 9 - 63
SERVICE PROCEDURES (Continued)
CAUTION: Do not rotate crankshaft or the plasti-
gage will be smeared.
(4) Install the main bearing cap carefully and
tighten the bolts to specified torque.(5) Carefully remove the bearing cap and measure
the width of the plastigage at the widest part using
the scale on the plastigage package (Fig. 9). Refer to
Crankshaft Clearance Specification Chart for proper
clearances. Also see Measuring Main and Connecting
Rod Bearing Clearance in Standard Service Proce-
dures.
CRANKSHAFT BEARING INSTALLATION
When the bearings need replacing, select and
install the proper bearing by the following procedure.
(1) Measure the crankshaft journal diameter and
confirm its classification from the following. In the
case of a bearing supplied as a service part, its iden-
tification color is painted at the position show in (Fig.
10).
NOTE: Service replacement parts have identifica-
tion marks, but factory-assembled parts have no
identification marks. Service crankshaft identifica-
tion may have marks or paint at counterweights.
Refer to Crankshaft Size Classification Chart.
Fig. 6 Measure Crankshaft Journal O.D.
Fig. 7 Measure Main Bearing I.D.
CRANKSHAFT SPECIFICATION CHART
Crankshaft End-Play
New Part: 0.05 - 0.25 mm
(0.002 - 0.001 in.)
Wear Limit: 0.30 mm (0.012 in.)
Main Bearing Oil Clearance
New Part: 0.018 - 0.036 mm
(0.0007 - 0.0014 in.)
Wear Part: 0.10 mm (0.0039 in.)
Crankshaft Main Bearing Journal
Standard Diameter: 59.980 mm (2.361 in.)
Crankshaft Connecting Rod Journal
Standard Diameter: 50.00 mm (1.968 in.)
Fig. 8 Measure Oil Clearance with Plastigage
Fig. 9 Measuring Clearance
9 - 64 3.0L ENGINENS
SERVICE PROCEDURES (Continued)
CHECKING CRANKSHAFT END PLAY
(1) Mount a dial indicator to front of engine, locat-
ing probe on nose of crankshaft (Fig. 11).
(2) Move crankshaft all the way to the rear of its
travel.
(3) Zero the dial indicator.
(4) Move crankshaft all the way to the front and
read the dial indicator. Refer to Crankshaft Specifi-
cation Chart.
CRANKSHAFT SIZE CLASSIFICATION CHART
SIZE NEW CURRENT
MAIN JOURNAL
59.982 - 59.988 mm
(2.3615 - 2.3617 in.)2 WHITE
ENAMEL
59.988 - 59.994 mm
(2.3617 - 2.3620 in.)1 NONE
59.994 - 60.000 mm
(2.3620 - 2.3622 in.)0 YELLOW
ENAMEL
CONNECTING ROD JOURNAL
49.980 - 49.985 mm
(1.9677 - 1.9679 in.)III WHITE
ENAMEL
49.985 - 49.995 mm
(1.9679 - 1.9683 in.)II NONE
49.995 - 50.000 mm
(1.9683 - 1.9685 in.)I YELLOW
ENAMEL
Fig. 10 Bearing Identification
Fig. 11 Checking Crankshaft End Play
CRANKSHAFT SPECIFICATION CHART
Crankshaft End-Play
New Part: 0.05 - 0.25 mm
0.002 - 0.001 in.)
Wear Limit: 0.30 mm (0.012 in.)
Main Bearing Oil Clearance
New Part: 0.018 - 0.036 mm
(0.0007 - 0.0014 in.)
Wear Part: 0.10 mm (0.0039 in.)
Crankshaft Main Bearing Journal
Standard Diameter: 59.980 mm (2.361 in.)
Crankshaft Connecting Rod Journal
Standard Diameter: 50.00 mm (1.968 in.)
NS3.0L ENGINE 9 - 65
SERVICE PROCEDURES (Continued)
(25) Remove ground straps to body.
(26) Raise vehicle enough to allow engine dolly
Special Tool 6135 and cradle Special Tool 6710 with
post Special Tool 6848 and adaptor Special Tool 6909
to be installed under vehicle (Fig. 24).
(27) Loosen cradle engine mounts to allow move-
ment for positioning onto engine locating holes on the
engine. Lower vehicle and position cradle mounts
until the engine is resting on mounts. Tighten
mounts to cradle frame. This will keep mounts from
moving when removing or installing engine and
transmission.
(28) Lower vehicle so the weight ofONLY THE
ENGINE AND TRANSMISSIONis on the cradle.
(29) Remove right engine mount assembly and left
transmission mount through bolt. Refer to Engine
Mounts Section of this Group.
(30) Raise vehicle slowly. It may be necessary to
move the engine/transmission assembly on the cradle
to allow for removal around body flanges.
INSTALLATION
(1) Position engine and transmission assembly
under vehicle and slowly lower the vehicle over the
engine and transmission. It may be necessary to
move the engine/transmission assembly with the cra-
dle for clearance around body flanges.
(2) Align engine and transmission mounts to
attaching points. Install mounting bolts at the right
engine and left transmission mounts. Refer to proce-
dures outlined in this section.(3) Slowly raise vehicle enough to remove the
engine dolly and cradle Special Tools 6135, 6710,
6848 and 6909.
(4) Remove Special tools 6910 and install bending
braces.
(5) Lower vehicle. Install generator and wiring
harness.
(6) Connect wiring harness on the front of the
engine.
(7) Install Air Conditioning Compressor.
(8) Install power steering pump and bracket and
accessory drive belt. Refer to Group 7. Accessory
Drive Belts Section for installation procedure.
(9) Raise vehicle and install axle shafts. Refer to
Group 2, Driveshafts for procedure.
(10) Install transmission and engine mount and
bracket assemblies. Refer to Engine Mounts in this
section for procedure.
(11) Connect exhaust system to manifold. Refer to
Group 11, Exhaust System and Intake Manifold for
procedure and torque specifications.
(12) Install left and right inner splash shields.
(13) Connect automatic transmission shifter link-
age. Refer to Group 21, Transmission for procedures.
(14) Lower vehicle and connect fuel line and
heater hoses. Remove plugs from rear heater hoses
and install, if equipped.
(15) Install ground straps. Connect engine and
throttle body connections and harnesses.
(16) Connect throttle body linkage. Refer to Group
14, Fuel System for procedure.
(17) Install radiator and fan module assembly.
Install radiator hoses. Fill cooling system. Refer to
Group 7, Cooling for procedures.
(18) Install battery tray, battery and cover.
(19) Install air cleaner and hoses.
(20) Install oil filter. Fill engine crankcase with
proper oil to correct level.
(21) Start engine and run until operating temper-
ature is reached.
(22) Adjust transmission linkage, if necessary.
CYLINDER HEAD COVER
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove air inlet resonator when removing left
head cover.
(3) When Removing left cylinder head cover,
remove dipstick tube.
(4) When removing right cylinder head cover
remove wiper unit. Refer to Wiper Unit Removal in
Group 8K.
(5) When removing right cylinder head cover,
remove accessory drive belt. Refer to Accessory Drive
Belt Removal in Group 7.
Fig. 24 Positioning Engine Cradle Support Post
MountsÐTypical
9 - 70 3.0L ENGINENS
REMOVAL AND INSTALLATION (Continued)
(6) When removing right cylinder head cover, dis-
connect generator wiring and remove generator.
(7) Relocate spark plug wires.
(8) Remove vacuum connections.
(9) Remove rocker cover screws and remove cover
(Fig. 25).
INSTALLATION
(1) Clean cylinder head and cover mating surfaces.
Install new gasket.
(2) See (Fig. 25) and apply sealant such as Mopar
Silicone Rubber Adhesive Sealant to cover ends.
(3) Install cover and tighten cover bolt washer and
gasket assembly to 10 N´m (88 in. lbs.).
(4) Reverse removal procedures for installation.
CAMSHAFT
REMOVAL
NOTE: SEE AUTO LASH ADJUSTER FUNCTION
CHECK BEFORE DISASSEMBLY
(1) Install auto lash adjuster retainers (Fig. 26).
(2) Remove distributor adaptor (Fig. 27).
(3) When removing camshaft bearing caps do not
remove the bolts from the bearing caps. Remove the
rocker arm, rocker shafts and bearing cap as an
assembly.
CAMSHAFT INSPECTION
(1) Inspect camshaft bearing journals for damage
and binding (Fig. 28). If journals are binding, also
check the cylinder head for damage. Also check cyl-
inder head oil holes for clogging.
(2) Front cylinder head camshaft check the tooth
surface of the distributor drive gear teeth of the cam-
shaft and replace if abnormal wear is evident (Fig.
28).
(3) Check the cam surface for abnormal wear and
damage and replace if defective. Also measure the
cam height (Fig. 28) and replace if out of limit, stan-
dard value is 41.25 mm (1.624 in.), wearlimitis
40.75 mm (1.604 in.).
CAMSHAFT INSTALL
Lubricate camshaft journals and cams with engine
oil and install camshaft on cylinder head.
Fig. 25 Rocker Cover
Fig. 26 Auto Lash Adjuster Retainers
NS3.0L ENGINE 9 - 71
REMOVAL AND INSTALLATION (Continued)
(3) Clean the area of the cylinder head where the
new cam plug will be installed.
(4)
Apply a light coating of Mopar Silicone Rubber
Adhesive Sealant to the outer diameter of the NEW cam
plug.
(5) Using a suitable installing tool and a hammer,
install the new cam plug to a depth of 0.5 mm (0.020
in.) below the surface of the cylinder head.
(6) Replace air cleaner assembly.
CAMSHAFT OIL SEAL PLUGÐ OUT OF
VEHICLE SERVICE
(1) Apply light coat of engine oil to the camshaft
oil seal lip.
(2) Install the oil seal using camshaft oil seal
installer tool MD-998713 (Fig. 31).
CAMSHAFT END SEAL (PLUG) SERVICE Ð
OUT OF VEHICLE SERVICE
Install end seal plug with Special Tool MD-998306
(Fig. 32).
Fig. 29 Rocker Arm Shaft Direction
Fig. 30 Distributor Drive
Fig. 31 Camshaft Oil SealÐInstallation
Fig. 32 Camshaft End Seal PlugÐInstallation
NS3.0L ENGINE 9 - 73
REMOVAL AND INSTALLATION (Continued)