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CYLINDER HEADS: Cylinder heads incorporate
valve shrouding to create turbulence-producing com-
bustion chambers, described as fast burn. Valve seat
and guides are inserts. A steel flanged composition
type gasket is used between head and block. VALVE 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 de-
signed to boost torque in the 3600 rpm range and
contributes 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.ENGINE MOUNTS
REMOVAL AND INSTALLATION
RIGHT SIDE MOUNT
(1) Remove the right engine mount insulator ver-
tical fasteners from frame rail. (2) Remove the load on the engine motor mounts
by carefully supporting the engine and transmission
assembly with a floor jack.
Fig. 1 3.3/3.8L V-6 Engine
Fig. 2 Engine Identification
Ä 3.3/3.8L ENGINE 9 - 99
Page 1666 of 2438

(3) Remove the thru bolt from the insulator assem-
bly. Remove insulator. (4) Reverse removal procedure for installation. Re-
fer to (Fig. 3) for bolt tightening specifications. (5) Engine mount adjustment, Refer to Engine
Mount Insulator Adjustment of this section.
FRONT MOUNT
(1) Support the engine and transmission assembly
with a floor jack so it will not rotate. (2) Remove the thru bolt from the insulator and
front crossmember mounting bracket. (3) Remove the front engine mount bracket to
front crossmember screws and nuts. Remove the in-
sulator assembly. (4) Reverse removal procedure for installation. Re-
fer to (Fig. 3) for bolt tightening specifications. (5) Engine mount adjustment, Refer to Engine
Mount Insulator Adjustment of this section.
LEFT SIDE MOUNT
(1) Raise vehicle on hoist and remove left front
wheel. (2) Remove inter splash shield.
(3) Support the transmission with a transmission
jack. (4) Remove the insulator thru bolt from the mount. (5) Remove the transmission mount fasteners and
remove mount. (6) Reverse removal procedure for installation. En-
sure that the slide tube is seated into the rail
bracket guides. Refer to (Fig. 3) for bolt tightening
specifications. (7) Engine mount adjustment, Refer to Engine
Mount Insulator Adjustment of this section.
ENGINE MOUNT RUBBER INSULATORS
Insulator location on yoke bracket to engine plate
(right side) and transmission bracket (left side) are
adjustable to allow right/left drive train adjustment
in relation to drive shaft assembly length. Check and reposition right engine mount insulator
(left engine mount insulator is floating type and will
adjust automatically (Fig. 4). Adjust drive train posi-
tion, if required, for the following conditions:
² Drive shaft distress: See Driveshafts in Suspen-
sion, Group 2.
² Any front end structural damage (after repair).
² Insulator replacement.
ENGINE MOUNT INSULATOR ADJUSTMENT
(1) Remove the load on the engine motor mounts
by carefully supporting the engine and transmission
assembly with a floor jack.
Fig. 3 Engine Mounting
9 - 100 3.3/3.8L ENGINE Ä
Page 1667 of 2438

(2) Loosen the right engine mount insulator yoke
screw and 2 turns on yoke nut, then loosen the front
engine mount bracket to front crossmember screws and
nuts. Left engine mount insulator is sleeved over
shaft and long support bolt to provide lateral
movement adjustment with engine weight re-
moved or not. (3) Pry the engine right or left as required to achieve
the proper drive shaft assembly length. See Drive
Shaft in Suspension Group 2 for driveshaft identifica-
tion and related assembly length measuring. (4) Tighten right engine mount insulator yoke nut to
102 N Im (75 ft. lbs.). Then tighten front engine mount
screws and nuts to 54 N Im (40 ft. lbs.) and center left
engine mount insulator. (5) Recheck drive shaft length.
ENGINE ASSEMBLY
REMOVAL
(1) Disconnect battery.
(2) Mark hood position at hinges and remove hood.
(3) Drain cooling system. Refer to Cooling System,
Group 7 for procedure. (4) Disconnect all electrical connections.
(5) Remove coolant hoses from radiator and engine.
(6) Remove radiator and fan assembly.
(7) See Fuel System, Group 14, to release fuel pres-
sure. Disconnect fuel lines and accelerator cable. (8) Remove air cleaner assembly.
(9) Hoist vehicle and drain engine oil.
(10) Remove air conditioning compressor mounting
bolts and set compressor aside. (11) Disconnect exhaust pipe at manifold.
(12) Remove transmission inspection cover and
mark flex plate to torque converter position. For disas-
sembly procedure for the all wheel drive vehicle refer to
Group 21 Transaxle. (13) Remove screws holding torque converter to
flex plate and attach C-clamp on bottom of converter
housing to prevent torque converter from counting
out. (14) Remove power steering pump mounting bolts
and set pump aside. (15) Remove two lower transmission to block
screws. (16) Remove starter.
(17) Lower vehicles and disconnect vacuum lines
and ground strap. (18) Install transmission holding fixture.
(19) Attach engine lifting hoist and support en-
gine. (20) Remove upper transmission case to block
bolts. (21) See Engine Mounting in (Fig. 3) and separate
mount/insulators as follows: (a) Mark RIGHT insulator on right rails sup-
ports. Remove insulator to rails screws. (b) Remove FRONT engine mount through bolt
and nut. (c) Remove LEFT insulator through bolt from in-
side wheelhouse or insulator bracket to transmis-
sion screws.
(22) Remove engine.
INSTALLATION
(1) Attach hoist and lower engine into engine com-
partment. (2) Align engine mounts and install but do not
tighten until all mounting bolts have been installed.
Tighten bolts to torque specified in (Fig. 3). (3) Install transmission case to cylinder block,
tighten bolts to 102 N Im (75 ft. lbs.) torque.
(4) Remove engine hoist and transmission holding
fixture. (5) Remove C-clamp from torque converter hous-
ing. Align flex plate to torque converter and install
mounting screws. Tighten to 75 N Im (55 ft. lb-
s.)torque. Refer to Group 21 transaxle for the all
wheel drive installation procedure. (6) Install transmission inspection cover.
(7) Connect exhaust system at manifold.
(8) Install starter.
(9) Install power steering pump and air condition-
ing compressor. For belt installation see Accessory
Belt Drive in Cooling System Group 7. (10) Lower vehicle and connect all vacuum lines.
(11) Connect all electrical connections including
ground strap. (12) Connect fuel lines and accelerator cable.
(13) Install radiator and fan assembly. Reconnect
fan motor electrical lead. Reinstall radiator hoses.
Fill cooling system. See Cooling System Group 7 for
filling procedure. (14) Fill engine crankcase with proper oil to cor-
rect level.
Fig. 4 Left Insulator Movement
Ä 3.3/3.8L ENGINE 9 - 101
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(15) Install hood.
(16) Connect battery.
(17) Start engine and run until operating temper-
ature is reached. (18) Adjust transmission or linkage if necessary.
ROCKER ARMS AND SHAFT ASSEMBLY
REMOVAL
(1) Remove upper intake manifold assembly. Refer
to Intake and Exhaust Manifolds, Group 11. (2) Disconnect spark plug wires by pulling on the
boot straight out in line with plug. (3) Disconnect closed ventilation system and evap-
oration control system from cylinder head cover. (4) Remove cylinder head cover and gasket.
(5) Remove four rocker shaft bolts and retainers.
(6) Remove rocker arms and shaft assembly.
(7) If rocker arm assemblies are disassembled for
cleaning or replacement. Assemble rocker arms in
their original position.Refer to (Fig. 5) for rocker arm
for positioning on the shaft.
INSTALLATION
(1) Install rocker arm and shaft assemblies with
the stamped steel retainers in the four positions,
tighten to 28 N Im (250 in. lbs.) (Fig. 5).
WARNING: THE ROCKER ARM SHAFT
SHOULD BE TORQUED DOWN SLOWLY,
STARTING WITH THE CENTERMOST BOLTS.
ALLOW 20 MINUTES TAPPET BLEED DOWN
TIME AFTER INSTALLATION OF THE
ROCKER SHAFTS BEFORE ENGINE OPERA-
TION. (2) Clean cylinder head cover gasket surface. In-
spect cover for distortion and straighten if necessary. (3) Clean head rail if necessary. Install a new gas-
ket and tighten cylinder head cover fasteners to 12
N Im (105 in. lbs.).
(4) Install closed crankcase ventilation system and
evaporation control system. (5) Install spark plug wires.
(6) Install upper intake manifold assembly. Refer to
Exhaust Systems and Intake Manifolds Group 11.
CYLINDER HEADS
The alloy aluminum cylinder heads shown in (Fig. 6)
are held in place by 9 bolts. The spark plugs are located
in peak of the wedge between the valves.
REMOVAL
(1) Drain cooling system refer to Cooling System
Group 7 for procedure and disconnect negative battery
cable. Remove intake manifold, and throttle body. Refer to
Group 11 Exhaust System and Intake Manifold. (2) Disconnect coil wires, sending unit wire, heater
hoses and by-pass hose. (3) Remove closed ventilation system, evaporation
control system and cylinder head covers. (4) Remove exhaust manifolds.
(5) Remove rocker arm and shaft assemblies. Re-
move push rods and identify to insure installation
in original locations. (6) Remove the 9 head bolts from each cylinder head
and remove cylinder heads (Fig. 7).
Fig. 5 Rocker Arm Location Left Blank
Fig. 6 Cylinder Head Assembly
Fig. 7 Cylinder Head Bolts Location
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INSPECTION
(1) Before cleaning, check for leaks, damage and
cracks. (2) Clean cylinder head and oil passages.
(3) Check cylinder head for flatness (Fig. 8).
(4) Inspect all surfaces with a straightedge if there is
any reason to suspect leakage. If out of flatness exceeds
.019mm (.00075 inch). 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
1mm (.004 inch) out of flat, allowable is 12 x .019mm
(.00075 inch) equals .22mm (.009 in.) This amount of
out of flat is acceptable. *Maximum of 0.2 mm (.008 inch) for grinding is
permitted.
CAUTION: This is a combined total dimension of
stock removal from cylinder head and block top
surface.
INSTALLATION
(1) Clean all surfaces of cylinder block and cylinder
heads. (2) Install new gaskets on cylinder block (Fig. 9).
The Cylinder head bolts are torqued using the
torque yield method, they should be examined
BEFORE reuse. If the threads are necked down,
the bolts should be replaced (Fig. 10).
Necking can be checked by holding a scale or straight
edge against the threads. If all the threads do not
contact the scale the bolt should be replaced. (3) Tighten the cylinder head bolts 1 thru 8 in the
sequence shown in (Fig. 11). Using the 4 step torque
turn method, tighten according to the following values:
² First-All to 61 N Im (45 ft. lbs.)
² Second-All to 88 N Im (65 ft. lbs.)
² Third-All (again) to 88 N Im (65 ft. lbs.)
² Fourth + 1/4 Turn Do not use a torque wrench
for this step (4) Bolt torque after 1/4 turn should be over 122
N Im(90 ft. lbs.). If not, replace the bolt.
(5) Tighten head bolt number 9 (Fig. 11) to 33 N Im
(25 ft. lbs.) after head bolts 1 thru 8 have been tighten
to specifications. (6) Inspect push rods and replace worn or bent rods.
(7) Install push rods, rocker arm and shaft assem-
blies with the stamped steel retainers in the four
positions, tighten to 28 N Im (250 in. lbs.) (Fig. 12).
Fig. 8 Check Cylinder Head
Fig. 9 Head Gasket Installation
Fig. 10 Checking Bolts for Stretching (Necking)
Fig. 11 Cylinder Head Tightening Sequence
Ä 3.3/3.8L ENGINE 9 - 103
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(8) Place new cylinder head cover gaskets in position
and install cylinder head covers. Tighten to 12 N Im
(105 in. lbs.).
INTAKE MANIFOLD SEALING
The intake manifold gasket is a one-piece stamped
steel gasket with a sealer applied from the manufac-
turer. This gasket has end seals incorporated with it. WARNING: INTAKE MANIFOLD GASKET IS
MADE OF VERY THIN METAL AND MAY CAUSE
PERSONAL INJURY, HANDLE WITH CARE. (1) Clean all surfaces of cylinder block and cylinder
heads. (2) Place a drop ( about 1/4 in. diameter) of Mopar
Silicone Rubber Adhesive Sealant or equivalent, onto
each of the fourmanifold to cylinder head gasket
corners (Fig. 13).
(3) Carefully install the intake manifold gasket (Fig.
14). Torque end seal retainer screws to 12 N Im (105 in.
lbs.). (4) Install intake manifold and (8) bolts and torque
to1N Im (10 in. lbs.). Then tighten bolts to 22 N Im
(200 in. lbs.) in sequence shown in (Fig. 15). Then
tighten again to 22 N Im (200 in. lbs.). After intake
manifold is in place, inspect to make sure seals are in place.
Refer to Group 11 Exhaust System and
Intake Manifold to complete Intake Manifold Assem-
bly. (5) Install exhaust manifolds and tighten bolts to
27 N Im (20 ft. lb.) and nuts to 20 N Im (15 ft. lbs.).
(6) Adjust spark plugs to specification in Electrical
Section, Group 8, and install the plugs.
VALVE SERVICE
VALVES AND VALVE SPRINGS
The valves are arranged in line in the cylinder
heads and inclined 18 degrees. The rocker shaft sup-
port are cast integral with the heads.
REMOVAL
(1) With cylinder head removed, compress valve
springs using Valve Spring Compressor Tool
C-3422-B with adapter 6412 as shown in (Fig. 16). (2) Remove valve retaining locks, valve spring re-
tainers, valve stem seals and valve springs.
Fig. 14 Intake Manifold Gasket Retainers
Fig. 15 Intake Manifold Removal and Installation
Fig. 12 Rocker Arm Shaft Retainers
Fig. 13 Intake Manifold Gasket Sealing
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(3) Before removing valves, remove any burrs
from valve stem lock grooves to prevent damage
to the valve guides. Identify valves to insure instal-
lation in original location.
VALVE INSPECTION
(1) Clean valves thoroughly and discard burned,
warped and cracked valves. (2) Measure valve stems for wear. Refer to specifica-
tions (Fig. 19). Valve stems are chrome plated and should not
be polished. (3) Remove carbon and varnish deposits from inside
of valve guides with a reliable guide cleaner. (4) Measure valve stem guide clearance as follows:(a) Install valve into cylinder head so it is 14mm
(.551 inch) off the valve seat. A small piece of hose
may be used to hold valve in place. (b) Attach dial indicator Tool C-3339 to cylinder
head and set it at right angle of valve stem being
measured (Fig. 17). (c) Move valve to and from the indicator. Refer to
specifications (Fig. 19).
Ream the guides for valves with oversized stems if
dial indicator reading is excessive or if the stems are
scuffed or scored. (5) Service valves with oversize stems and over size
seals are available in 0.15mm (.005 inch), 0.40mm,
(.015 inch) and 0.80mm (.030 inch) oversize. Oversize seals must be used with oversize
valves. Reamers to accommodate the oversize valve stem are
as follows:
(6) Slowly turn reamer by hand and clean guide
thoroughly before installing new valve. Do not at-
tempt to ream the valve guides from standard
directly to 0.80mm (.030 inch) Use step procedure
of 0.15mm (.005 inch), 0.40mm (.015 inch) and
0.80mm (.030 inch) so the valve guides may be
reamed true in relation to the valve seat. After
reaming guides, the seat runout should be mea-
sured and resurfaced if necessary. See Refacing
Valves and Valve Seats.
VALVE GUIDES
Replace cylinder head if guide does not clean
up with 0.80mm (.030 inch) oversize reamer, or if
guide is loose in cylinder head.
Fig. 18 Intake and Exhaust Valves
Fig. 19 Valve Guide Specifications
Fig. 16 Compress Valve Springs with Special Tool C-3422B with adapter 6412
Fig. 17 Measuring Valve Guide Wear
Ä 3.3/3.8L ENGINE 9 - 105
Page 1672 of 2438

REFACING VALVES AND VALVE SEATS
The intake and exhaust valves have a 44-1/2 to 45
degree face angle. The valve seats have a 45 to 45-
1/2 degree face angle. The valve face and valve seat
angles are shown in (Fig. 21).
VALVES
(1) Inspect the remaining margin after the valves
are refaced Refer to specifications (Fig. 20).
VALVE SEATS
CAUTION: Do not un-shroud cylinder head from
around the valve during valve seat refacing (Fig.
22).
(1) 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 ob-
tained. (2) Measure the concentricity of valve seat using
dial indicator. Total runout should not exceed
.051mm (.002 inch) total indicator reading.
(3) Inspect the valve seat with Prussian blue to de-
termine where the valve contacts the seat. To do this, coat valve seat
LIGHTLYwith 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 valve face,lower valve seat with a
15 degree stone. If the blue is transferred to the bottom
edge of valve face raise valve seat with a 65 degrees
stone. Valve seats which are worn or burned can be
reworked, provided that correct angle and seat
width are maintained. Otherwise cylinder head
must be replaced. (4) When seat is properly positioned the width of
intake seats should be 1.75 to 2.25mm (0.69 to .088
inch) The width of the exhaust seats should be 1.50 to
2.00mm (.059 to .078 inch) (Fig. 21) (5) Check the valve spring installed height after
refacing the valve and seat (Fig. 24).
TESTING VALVE SPRINGS
Whenever valves have been removed for inspection,
reconditioning or replacement, valve springs should be
tested (Fig. 23). As an example; the compression
Fig. 23 Testing Valve Spring with Tool C-647
Fig. 20 Valve Dimensions
Fig. 21 Valve Seats
Fig. 22 Refacing Valve Seats
9 - 106 3.3/3.8L ENGINE Ä