
BALANCE SHAFTS
Balance shaft lubrication is provided through an
oil passage from the number 1 main bearing cap
through the balance shaft carrier support leg. This
passage directly supplies oil to the front bearings and
internal machined passages in the shafts that routes
oil from front to rear shaft bearing journals
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
BALANCE SHAFTS:2.4L engines are equipped
with two balance shafts installed in a carrier
attached to the lower crankcase. The shafts intercon-
nect through gears to rotate in opposite directions.These gears are driven by a short chain from the
crankshaft, to rotate at two times crankshaft speed.
This counterbalances certain engine reciprocating
masses.
CYLINDER BLOCK AND BEDPLATE ASSEM-
B LY:A closed deck design is used for cooling and
weight reduction with water pump molded into the
block. Nominal wall thickness is 4.5 mm. The bed-
plate 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 60 mm diameter
main and 50 mm diameter crank pin journals (all)
have undercut fillets that are deep rolled for added
strength. To evenly distribute bearing loads and min-
imize internal stress, 8 counterweights are used.
Hydrodynamic seals provide end sealing, where the
crankshaft exits the block. Anaerobic gasket material
is used for parting line sealing in the block. A sin-
tered powder metal timing belt sprocket is mounted
on the crankshaft nose. This sprocket provides
motive power; via timing belt to the camshaft sprock-
ets (providing timed valve actuation) and to the
water pump.
PISTONS:There is provisions for free wheeling
valve train. Piston has a unique height. All engines
use pressed in piston pins to attach forged powder
metal connecting rods. Incorporate hex head cap
screw threaded into the connecting rod. Piston and
Rods are serviced as a assembly.
PISTONS RINGS:The piston rings include a
molybdenum faced top ring for reliable compression
EngineÐ2.4L
Fig. 1 Engine Identification
NS2.4L ENGINE 9 - 15
DESCRIPTION AND OPERATION (Continued)

sealing and a chrome plated taper faced intermediate
ring for additional cylinder pressure control. There
are also standard oil control rings.
CYLINDER HEAD:Features a Dual Over Head
Camshaft (DOHC) 4 valves per cylinder cross flow
design. The valves are arranged in two inline banks,
with the ports of the bank of two intake valves per
cylinder facing toward the radiator side of engine
and ports of the bank of two exhaust valves per cyl-
inder facing toward the dash panel. Incorporates
powder metal valve guides and seats. Integral oil gal-
leys within the cylinder head supplies oil to the
hydraulic lash adjusters, camshaft and valve mecha-
nisms.
CAMSHAFTS:The nodular iron camshafts have
six bearing journals and 2 cam lobes per cylinder.
Flanges at the rear journals control camshaft end
play. Provision for cam position sensor is located on
the intake camshaft at the rear of cylinder head. A
hydrodynamic oil seal is used for oil control at the
front of the camshaft.
VALVES:4 valves per cylinder are actuated by
roller cam followers which pivot on stationary
hydraulic lash adjusters. All valves have 6 mm diam-
eter chrome plated valve stems. The valve sizes are
34.8 mm (1.370 inch.) diameter intake valves and
30.5 mm (1.20 inch.) diameter exhaust valves. Viton
rubber valve stem seals are integral with the spring
seats. Valve springs, spring retainers, and locks are
conventional.
INTAKE MANIFOLD:The intake manifold is a
two piece aluminum casting, attached to the cylinder
head with ten screws. This long branch fan design
enhances low and midspeed torque, while minimizing
undesirable inlet noise.
EXHAUST MANIFOLD:The exhaust manifold is
made of cast iron for strength and high tempera-
tures.
ENGINE LUBRICATION:Refer to Group 0
Lubrication and Maintenance for recommended oil to
be used in various engine application. System is full
flow filtration, pressure feed type. The oil pump is
mounted in the front engine cover and driven by the
crankshaft. Pressurized oil is then routed through
the main oil gallery, running the length of the cylin-
der block, supplying main and rod bearings with fur-
ther routing. Pistons are lubricated from rod bearing
throw off and lubricating slots on the connecting rod
assemblies. Camshaft and valve mechanisms are
lubricated from a full length cylinder head oil gallery
supplied from the crankcase main oil gallery.DIAGNOSIS AND TESTING
CHECKING ENGINE OIL PRESSURE
(1) Remove oil pressure sending unit and install
gauge assembly C-3292.
(2) Run engine until thermostat opens.
CAUTION: If oil pressure is 0 at idle, Do Not Run
engine at 3000 RPM
(3) Oil Pressure:Curb Idle25 kPa (4 psi) mini-
mum3000 RPM170/550 kPa (25/80 psi).
(4) If oil pressure is 0 at idle. Shut off engine,
check for pressure relief valve stuck open or a
clogged oil pickup screen.
SERVICE PROCEDURES
FITTING PISTONS
Piston and cylinder wall must be clean and dry.
Piston diameter should be measured 90 degrees to
piston pin about 14 mm (9/16 inch.) from the bottom
of the skirt as shown in (Fig. 3). Cylinder bores
should be measured halfway down the cylinder bore
and transverse to the engine crankshaft center line
shown in (Fig. 2). Refer to Cylinder Bore and Piston
Specification Chart.
Correct piston to bore clearance must be estab-
lished in order to assure quiet and economical oper-
ation.
Chrysler engines use pistons designed specifically
for each engine model. Clearance and sizing locations
vary with respect to engine model.
NOTE: Pistons and cylinder bores should be mea-
sured at normal room temperature, 70ÉF (21ÉC).
FITTING PISTON RINGS
(1) Wipe cylinder bore clean. Insert ring and push
down with piston to ensure it is square in bore. The
ring gap measurement must be made with the ring
positioning at least 12 mm (0.50 inch) from bottom of
cylinder bore. Check gap with feeler gauge (Fig. 4).
Refer to specification in Piston Ring Specification
Chart.
(2) Check piston ring to groove side clearance (Fig.
5). Refer to specification in Piston Ring Specification
Chart.
9 - 16 2.4L ENGINENS
DESCRIPTION AND OPERATION (Continued)

OPTIONAL CRANKSHAFT END PLAY CHECK
(1) Move crankshaft all the way to the rear of its
travel using a lever inserted between a main bearing
cap and a crankshaft cheek, using care not to dam-
age any bearing surface.DO NOTloosen main bear-
ing cap.
(2) Use a feeler gauge between number three
thrust bearing and machined crankshaft surface to
determine end play.
VALVE SERVICE RECONDITION
VALVE REMOVAL
(1) With cylinder head removed, compress valve
springs using Special Tool C-3422-B or equivalent.
(2) Remove valve retaining locks, valve spring
retainers, valve stem seals and valve springs.
(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 INSPECTION
(1) Clean valves thoroughly and discard burned,
warped and cracked valves.
(2) Measure valve stems for wear. Measure stem
about 60 mm beneath the valve lock grooves.
(3) If valve stems are worn more than 0.05 mm
(0.002 in.), replace valve.
VALVE GUIDES
(1) Remove carbon and varnish deposits from
inside of valve guides with a reliable guide cleaner.
(2) Using a small hole gauge and a micrometer,
measure valve guides in 3 places top, middle and bot-
tom (Fig. 15). Refer to Valve Guide Specification
Chart. Replace guides if they are not within specifi-
cation.
(3) Check valve guide height (Fig. 16).
TESTING VALVE SPRINGS
(1) Whenever valves have been removed for inspec-
tion, reconditioning or replacement, valve springs
should be tested. As an example, the compression
length of the spring to be tested is 33.34 mm (1 5/16inches). Turn tool table until surface is in line with
the 33.34 mm (1 5/16 in.) mark on the threaded stud
and the zero mark on the front. Place spring over
stud on the table and lift compressing lever to set
tone device (Fig. 17). Pull on torque wrench until
ping is heard. Take reading on torque wrench at this
instant. Multiply this reading by two. This will give
the spring load at test length. Fractional measure-
ments are indicated on the table for finer adjust-
ments. Discard the springs that do not meet
specifications. The Following specifications apply to
both intake and exhaust valve springs;
²Valve Closed Nominal TensionÐ 76 lbs. @ 38.0
mm (1.50 in.)
²Valve Open Nominal TensionÐ 136 lbs. @ 29.75
mm (1.17 in.)
(2) Inspect each valve spring for squareness with a
steel square and surface plate, test springs from both
ends. If the spring is more than 1.5 mm (1/16 inch)
out of square, install a new spring.
REFACING VALVES AND VALVE SEATS
(1) The intake and exhaust valve seats and valve
face have a 45 and a 45 1/2 degree angles.
Fig. 15 Checking Wear on Valve GuideÐTypical
VALVE GUIDE SPECIFICATION CHART
Valve Guide Diameter
Intake and
Exhaust Valve:5.975 - 6.000 mm
(0.2352 - 0.2362 in.)
Valve Guide Clearance
New Service
Limit
Intake Valve: 0.048 - 0.066 mm
(0.0018 - 0.0025 in.)
0.25 mm
(0.010 in.)
Exhaust Valve: 0.0736 - 0.094 mm
(0.0029 - 0.0037 in.)
Fig. 16 Valve Guide Height
NS2.4L ENGINE 9 - 21
SERVICE PROCEDURES (Continued)

(2) Inspect the remaining margin after the valves
are refaced (Fig. 18). Intake valves with less than 1.2
mm (3/64 inch.) margin and Exhaust valves with less
than 0.9 mm (1/32 inch.) margin should be discarded.
(3) When refacing valve seats, it is important that
the correct size valve guide pilot be used for reseat-
ing stones. A true and complete surface must be
obtained.
(4) Measure the concentricity of valve seat and
valve guide using a valve seat runout dial indicator.
Total runout should not exceed. 0.051 mm (0.002
inch.) (total indicator reading).
(5) Inspect the valve seat with Prussian blue to
determine where the valve contacts the seat. To do
this, coat valve seatLIGHTLYwith Prussian blue
then set valve in place. Rotate the valve with light
pressure. If the blue is transferred to the center of
valve face, contact is satisfactory. If the blue is trans-
ferred to top edge of the valve face, lower valve seat
with a 15 degrees stone. If the blue is transferred to
the bottom edge of valve face raise valve seat with a
65 degrees stone.²Intake valve seat diameter is 34.37 34.63 mm
(1.158 1.363 inch.)
²Exhaust valve seat diameter is 29.37 29.63 mm
(1.156 1.166 inch.)
(6) Valve seats which are worn or burned can be
reworked, provided that correct angle and seat width
are maintained. Otherwise the cylinder head must be
replaced.
(7) When seat is properly positioned the width of
intake and exhaust seats should be 0.9 to 1.3 mm
(0.35 to 0.051 inch.) (Fig. 19).
(8) Check valve tip height dimensions A after
grinding the valve seats or faces (Fig. 20). Grind
valve tip to 47.99 mm (1.889 in.) for exhaust valve
and 48.04 mm (1.891 in.) for intake valve when
installed in the head. The valve tip chamfer may
Fig. 17 Testing Valve Springs
Intake and Exhaust Valves
VALVE SPECIFICATION CHART
Face Angle
Intake and Exhaust: 44.5É-45É
Head Diameter
Intake: 34.67 - 34.93 mm
(1.364 - 1.375 in.)
Exhaust: 30.37 - 30.63 mm
(1.195 - 1.205 in.)
Length (Overall)
Intake: 112.76 - 113.32 mm
(4.439 - 4.461 in.)
Exhaust: 109.59 - 110.09 mm
(4.314 - 4.334 in.)
Stem Diameter
Intake: 5.934 - 5.952 mm
(0.2337 - 0.2344 in.)
Exhaust: 5.906 - 5.924 mm
(0.2326 - 0.2333 in.)
Valve Margin
Intake: 1.285 - 1.615 mm
(0.050 - 0.063 in.)
Exhaust: 0.985 - 1.315 mm
(0.038 - 0.051 in.)
Fig. 18 Refacing Intake and Exhaust Valves
9 - 22 2.4L ENGINENS
SERVICE PROCEDURES (Continued)

need to be reground to prevent seal damage when
the valve is installed.
VALVE INSTALLATION
(1) Coat valve stems with clean engine oil and
insert in cylinder head.
(2) Install new valve stem seals on all valves using
a valve stem seal tool (Fig. 21). The valve stem seals
should be pushed firmly and squarely over valve
guide.CAUTION: When oversize valves are used, the cor-
responding oversize valve seal must also be used.
Excessive guide wear may result if oversize seals
are not used with oversize valves.
(3) Install valve springs and retainers. Compress
valve springs only enough to install locks, taking
care not to misalign the direction of compression.
Nicked valve stems may result from misalignment of
the valve spring compressor.
CAUTION: When depressing the valve spring
retainers with valve spring compressor the locks
can become dislocated. Check to make sure both
locks are in their correct location after removing
tool.
(4) Check the valve spring installed height B after
refacing the valve and seat (Fig. 20). Make sure mea-
surements are taken from top of spring seat to the
bottom surface of spring retainer. If height is greater
than 38.75 mm (1.525 in.), install a .762 mm (0.030
inch.) spacer under the valve spring seat to bring
spring height back within specification.
(5) Install rocker arm shafts as previously
described in this section.
(6) Checking dry lash. Dry lash is the amount of
clearance that exists between the base circle of an
installed cam and the rocker arm roller when the
adjuster is drained of oil and completely collapsed.
Specified dry lash is 1.17 mm (0.046 in.) for intake
and 1.28 mm (0.050 in.) for exhaust. After performing
dry lash check, refill adjuster with oil and allow 10
minutes for adjuster/s to bleed down before rotating
cam.
REMOVAL AND INSTALLATION
ENGINE MOUNTÐFRONT
REMOVAL
(1) Support the engine and transaxle assembly
with a floor jack so it will not rotate.
(2) Remove the front engine mount through bolt
from the insulator and front crossmember mounting
bracket (Fig. 22).
(3) Remove six screws from air dam to allow
access to the front mount screws.
(4) Remove the front engine mount screws and
remove the insulator assembly.
(5) Remove the front mounting bracket, if neces-
sary (Fig. 22).
INSTALLATION
(1) Reverse removal procedure for installation and
tighten fasteners in this order. For engine mount
Fig. 19 Refacing Valve Seats
Fig. 20 Checking Spring Installed Height and Valve
Tip Height Dimensions
Fig. 21 Valve Stem Oil Seal Special Tool C4745
NS2.4L ENGINE 9 - 23
SERVICE PROCEDURES (Continued)

(3) If valve stems are worn more than 0.05 mm
(.002 in.), replace valve.
VALVE SPRINGS
(1) Whenever valves have been removed for
inspection, reconditioning or replacement, valve
springs should be tested for correct tension. Discard
the springs that do not meet specifications. The fol-
lowing specifications apply to both intake and
exhaust valves springs:
²Valve Closed Nominal TensionÐ 76 lbs. @ 38.0
mm (1.50 in.)
²Valve Open Nominal TensionÐ 136 lbs. @ 29.75
mm (1.17 in.)
(2) Inspect each valve spring for squareness with
a steel square and surface plate, test springs from
both ends. If the spring is more than 1.5 mm (1/16
inch) out of square, install a new spring.
CRANKSHAFT
The crankshaft journals should be checked for
excessive wear, taper and scoring (Fig. 99). Limits of
taper or out-of-round on any crankshaft journals
should be held to .025 mm (.001 inch). Journal grind-
ing should not exceed .305 mm (.012 inch) under the
standard journal diameter.DO NOTgrind thrust
faces of Number 3 main bearing.DO NOTnick
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.
OIL PUMP
(1) Clean all parts thoroughly. Mating surface of
the oil pump should be smooth (Fig. 100). Replace
pump cover if scratched or grooved.(2) Lay a straightedge across the pump cover sur-
face (Fig. 101). 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 9.40 mm (0.370 in.)
or less (Fig. 102), or if the diameter is 79.95 mm
(3.148 in.) or less, replace outer rotor.
(4) If inner rotor measures 9.40 mm (0.370 in.) or
less replace inner rotor (Fig. 103).
(5) Slide outer rotor into pump housing, press to
one side with fingers and measure clearance between
rotor and housing (Fig. 104). If measurement is 0.39
mm (0.015 in.) or more, replace housing only if outer
rotor is in specification.
(6) Install inner rotor into pump housing. If clear-
ance between inner and outer rotors (Fig. 105) is
0.203 mm (0.008 in.) or more, replace both rotors.
(7) Place a straightedge across the face of the
pump housing, between bolt holes. If a feeler gauge
of 0.102 mm (0.004 in.), or more can be inserted
Fig. 99 Crankshaft Journal Measurements
Fig. 100 Oil Pump
Fig. 101 Checking Oil Pump Cover Flatness
9 - 52 2.4L ENGINENS
CLEANING AND INSPECTION (Continued)

VALVE SEAT
Inspect the valve seat with Prussian blue to deter-
mine where the valve contacts the seat. To do this,
coat valve seatLIGHTLYwith Prussian blue then
set valve in place. Rotate the valve with light pres-
sure. If the blue is transferred to the center of valve
face, contact is satisfactory. If the blue is transferred
to top edge of the valve face, lower valve seat with a
15 degrees stone. If the blue is transferred to the bot-
tom edge of valve face raise valve seat with a 65
degree stone (Fig. 17).
INSTALLATION
(1) Install valve spring seat.
(2) Using suitable tool install seal by tapping
lightly until seal is in place (Fig. 18).
(3) Install valve spring with the enamelled ends
facing the rocker arms (Fig. 19).
CAUTION: During reassembly, compressing the
valve spring more than necessary to install valve
spring retainer locks can cause the retainer to be
forced against the stem seal and damaging it.
VALVE SPECIFICATION CHART
Valve Dimensions
INTAKE VALVE (MINIMUM)
Stem Diameter: 7.960 mm (0.313 in.)
Face Angle: 45É
Valve Margin: 0.700 mm (0.028 in.)
Length: 103.0 mm (4.055 in.)
EXHAUST VALVE (MINIMUM)
Stem Diameter: 7.930 mm (0.312)
Face Angle: 45É
Valve Margin: 1.50 mm (0.059 in.)
Length: 102.70 mm (4.043 in.)
Valve Guide
ClearanceNew Service
Limit
Intake: 0.03 - 0.06 mm
(0.001 - 0.002 in.)0.10 mm
(0.004 in.)
Exhaust: 0.05 - 0.09 mm
(0.002 - 0.0035 in.)0.15 mm
(0.006 in.)
Valve Springs New Service
Limit
Free Length: 49.8 mm (1.960 in.) 48.8 mm
(1.921 in.)
Squarness: 2É Maximum 4É Maximum
Spring Tension: 33 Kg @ 40.4 mm
(73 lbs. @ 1.59 in.)
Fig. 16 Valve Spring
Fig. 17 Valve Seat Reconditioning
Fig. 18 Install Valve Stem Seals
Fig. 19 Installed Valve Spring Position
NS3.0L ENGINE 9 - 67
SERVICE PROCEDURES (Continued)

(2) Tighten mount to transmission bolts to 55 N´m
(40 ft. lbs.) (Fig. 22).
Tighten through bolt to 75 N´m (55 ft. lbs.)
(3) Engine mount adjustment, Refer to Engine
Mount Insulator Adjustment of this section.
REAR MOUNT
(1) Raise vehicle on hoist.
(2) Support the transmission with a transmission
jack so it will not rotate.
(3) Remove the insulator through bolt from the
mount and rear suspension crossmember.
(4) Remove the four transmission mount fasteners
and remove the mount.
(5) Reverse the removal procedure for installation.
Refer to (Fig. 23).
ENGINE MOUNT RUBBER INSULATORS
Insulator location on (right side) is adjustable to
allow right/left drive train adjustment in relation to
driveshaft assembly length. See Engine Mount
Adjustments in this section.
Check and reposition right engine mount insulator.
Adjust drive train position, if required, for the follow-
ing conditions:
²Driveshaft distress: See Group 2, Suspension
and Driveshafts.
²Any front end structural damage (after repair).
²Insulator replacement.
ENGINE ASSEMBLY
REMOVAL
(1) Perform fuel pressure release procedure. Refer
to Group 14, Fuel System for procedure. Remove fuel
line to fuel rail.
(2) Disconnect battery.
(3) Remove Air cleaner and hoses.
(4) Remove battery cover, battery and battery tray,
with integral vacuum reservoir, from vehicle.
(5) Block off heater hoses to rear heater assembly,
if equipped.
(6) Drain cooling system. Refer to Group 7, Cooling
System for procedure.
(7) Disconnect heater hoses.
(8) Remove fan module and radiator. Refer to
Group 7, Cooling System for procedure.
(9) Disconnect transmission shift linkage.
(10) Disconnect throttle body linkage and vacuum
hoses from throttle body.
(11) Remove accessory drive belts. Refer to Acces-
sory Drive System located in Group 7, Cooling Sys-
tem for procedure.
(12) Remove air conditioning compressor from
engine and set it aside.
(13) Disconnect generator wiring harness and
remove generator.
(14) Hoist vehicle and remove axle shafts. Refer to
Group 2, Driveshaft for procedure.
(15) Remove right and left inner splash shields.
(16) Disconnect exhaust pipe from manifold.
(17) Remove front engine mount and bracket as an
assembly.
(18) Remove rear transmission mount and bracket.
(19) Remove power steering pump and bracket
assembly.
(20) Remove wiring harness and connectors from
front of engine.
(21) Remove bending braces and install tool num-
ber 6910 on engine.
(22) Remove trans inspection cover and mark flex-
plate to torque converter.
(23) Remove driveplate to torque converter bolts.
(24) Lower the vehicle.
Fig. 22 Engine MountÐLeft
Fig. 23 Engine MountÐRear
NS3.0L ENGINE 9 - 69
REMOVAL AND INSTALLATION (Continued)