1996 CHRYSLER VOYAGER ESP

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)

(4) Install cylinder head cover using procedure out-
lined in this section.
(5) Install rear timing belt cover and timing belt
idler pulley.
(6) Install timing belt and camshaft sprocket.
Refer to procedure outlined in this section.
(7) Install cam sensor and fuel injectors wiring
connectors.
(8) Install coil pack and plug wires onto the
engine. Connect coil pack wiring connector.
(9) Install power steering pump assembly.
(10) Raise vehicle and install the exhaust pipe to
the manifold.
(11) Install power brake vacuum hose to the intake
manifold.
(12) Install accessory drive belts. Refer to Group 7,
Cooling System for procedure.
(13) Install throttle linkage. Refer to Group 14,
Fuel System for procedures.
(14) Install air cleaner and connect all vacuum
lines, electrical wiring and fuel lines to the throttle
body.
(15) Fill cooling system. Refer to Group 7, Cooling
System for procedure. Connect negative battery
cable.
VALVES AND VALVE SPRINGS
REMOVAL
(1) With cylinder head removed, compress valve
springs using a universal valve spring compressor.
(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.
(4) Inspect and clean the valves. Refer to Cleaning
and Inspection outlined in this section for procedure.
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. 51). 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. Ensure both locks are in
the correct location after removing tool.
(4) Check the valve spring installed height B after
refacing the valve and seat (Fig. 52). 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
in.) spacer under the valve spring seat to bring
spring height back within specification.
Fig. 50 Cylinder Head Tightening Sequence
Fig. 51 Valve Stem Oil Seal Tool
NS2.4L ENGINE 9 - 35
REMOVAL AND INSTALLATION (Continued)

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)

c. Lower oil ring side rail.
d. No. 2 Intermediate piston ring.
e. No. 1 Upper piston ring.
(2) Install the side rail by placing one end between
the piston ring groove and the expander. Hold end
firmly and press down the portion to be installed
until side rail is in position.Do not use a piston
ring expander(Fig. 52).
(3) Install upper side rail first and then the lower
side rail.
(4) Install No. 2 piston ring and then No. 1 piston
ring (Fig. 53).
(5)
Position piston ring end gaps as shown in (Fig. 54).
(6) Position oil ring expander gap at least 45É from
the side rail gaps butnoton the piston pin center or
on the thrust direction.
(7) Connecting rod front mark 72 must always face
forward, toward timing belt end. (Fig. 55)
(8) Install the piston and connecting rod assembly
into there respective bore from the cylinder block top.
CAUTION: Piston assemblies are not to be inter-
changed from bank to bank.(9) Check alignment marks made during disassem-
bly and that bearing position notches new or used
are on the same side as shown in (Fig. 56).
Fig. 52 Side RailÐInstallation
Fig. 53 Installing Upper and Intermediate Rings
Fig. 54 Piston Ring End Gap Position
Fig. 55 Identify Piston and Rod Assembly for
Cylinder Installation
Fig. 56 Connecting Rod and Cap
9 - 80 3.0L ENGINENS
REMOVAL AND INSTALLATION (Continued)

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)

(4) If oil pressure is 0 at idle. Shut off engine,
check for pressure relief valve stuck open, a clogged
oil pick-up screen or a damaged oil pick-up tube
O-ring.
SERVICE PROCEDURES
CYLINDER BORE AND PISTON SIZING
The cylinder walls should be checked for out-of-
round and taper with Tool C-119 (Fig. 3). The cylin-
der bore out-of-round is 0.050 mm (.002 inch)
maximum and cylinder bore taper is 0.051 mm (0.002
inch) maximum. If the cylinder walls are badly
scuffed or scored, the cylinder block should be
rebored and honed, and new pistons and rings fitted.
Whatever type of boring equipment is used, boring
and honing operation should be closely coordinated
with the fitting of pistons and rings in order that
specified clearances may be maintained.Refer to
Honing Cylinder Bores outlined in the Stan-
dard Service Procedures for specification and
procedures.
Measure the cylinder bore at three levels in direc-
tions A and B (Fig. 3). Top measurement should be
10 mm (3/8 inch) down and bottom measurement
should be 10 mm (3/8 inch.) up from bottom of bore.
Refer to Cylinder Bore and Piston Specifications
Chart.
SIZING PISTONS
Piston and cylinder wall must be clean and dry.
Piston diameter should be measured 90 degrees to
piston pin about 17.5 mm (11/16 inch) from the bot-tom of the skirt as shown in (Fig. 4). Cylinder bores
should be measured halfway down the cylinder bore
and transverse to the engine crankshaft center line
shown in (Fig. 3). Refer to Cylinder Bore and Speci-
fications Table. Correct piston to bore clearance must
be established in order to assure quiet and economi-
cal operation.
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, 21ÉC (70ÉF).
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. 5).
Refer to Piston Ring Specification Chart.
Fig. 3 Checking Cylinder Bore Size
CYLINDER BORE AND PISTON
SPECIFICATION CHART
Standard Bore Maximum
Out-of-RoundMaximum
Taper
87.5 mm
(3.445 in.)0.051 mm
(0.002 in.)0.051 mm
(0.002 in.)
Standard Piston Size
Federal
Emission:87.463 - 87.481 mm
(3.4434 - 3.4441 in.)
Low Emission
Vehicle (LEV):87.456 - 87.474 mm
(3.4432 - 3.4439 in.)
Piston to Bore Clearance
Federal
Emission:0.012 - 0.044 mm
(0.0004 - 0.0017 in.)
Low Emission
Vehicle (LEV):0.18 - 0.050 mm
(0.0008 - 0.0020 in.)
Measurements Taken at Piston Size Location
Fig. 4 Piston Measurements
9 - 4 ENGINENS/GS
DIAGNOSIS AND TESTING (Continued)

scratches are present, replace the camshaft and
check the cylinder head for damage. Replace the
cylinder head if worn or damaged. Check the lobes
for pitting and wear. If the lobes show signs of
wear, check the corresponding rocker arm roller for
wear or damage. Replace rocker arm/hydraulic lash
adjuster if worn or damaged. If lobes show signs of
pitting on the nose, flank or base circle; replace the
camshaft.
INSTALLATION
(1) Lubricate the camshaft journals with oil and
install camshaftwithoutrocker arm assemblies
installed.
(2) Install camshaft target magnet into the end of
the camshaft. Tighten mounting screw to 3.4 N´m (30
in. lbs.).
(3) Install camshaft position sensor and tighten
mounting screws to 9 N´m (80 in. lbs.).
(4) Measure camshaft end play using the following
procedure:
²Mount dial indicator C-3339 or equivalent, to a
stationary point on cylinder head (Fig. 13).
²Using a suitable tool, move camshaft to rear-
ward limits of travel.
²Zero the dial indicator.
²Move camshaft forward to limits of travel and
read dial indicator.
²End play travel: 0.13 - 0.33 mm (0.005 - 0.013
in.).
(5) Install front camshaft seal. Camshaft must be
installed before the camshaft seal is installed. Refer
to procedure outlined in this section.
(6) Install cylinder head. Refer to procedure out-
lined in this section.
(7) Install camshaft sprocket and tighten to 115
N´m (85 ft. lbs.).
(8) Install inner timing belt cover.(9) Install timing belt tensioner and timing belt.
Refer to procedures outlined in this section.
(10) Install rocker arm assemblies in correct order
as removed. Tighten the rocker arm assemblies in
sequence shown in (Fig. 14) to 28 N´m (250 in. lbs.).
(11) Install cylinder head cover and tighten fasten-
ers to 12 N´m (105 in. lbs.).
(12) Install ignition coil pack and ignition cables.
(13) Perform camshaft and crankshaft timing
relearn procedure as follows:
²Connect the DRB scan tool to the data link
(diagnostic) connector. This connector is located in
the passenger compartment; at the lower edge of
instrument panel; near the steering column.
²Turn the ignition switch on and access the ªmis-
cellaneousº screen.
²Select ªre-learn cam/crankº option and follow
directions on DRB screen.
ROCKER ARM/HYDRAULIC LASH ADJUSTER
REMOVAL
(1) Remove valve cover using procedure outlined in
this section.
(2) Identify the rocker arm shaft assemblies before
removal.
(3) Loosen the attaching fasteners. Remove rocker
arm shaft assemblies from cylinder head.
(4) Identify the rocker arms spacers and retainers
for reassembly. Disassemble the rocker arm assem-
blies by removing the attaching bolts from the shaft
(Fig. 15).
(5) Slide the rocker arms and spacers off the shaft.
Keep the spacers and rocker arms in the same loca-
tion for reassembly.
Fig. 13 Camshaft End Play
Fig. 14 Rocker Arm Shaft Tightening Sequence
9 - 8 ENGINENS/GS
REMOVAL AND INSTALLATION (Continued)