113.45 - 114.21 mm
Exhaust
(4.4666 - 4.4965)
114.92 - 115.68 mm (4.5244 - 4.5543 in.)
Intake
6.931 - 6.957 mm
(0.2729 - 0.2739 in.)
Stem Diameter
Stem - to - Guide Clearance
Intake
0.018 - 0.069 mm
(0.0008 - 0.0028 in.)
Exhaust
0.047 - 0.098 mm
(0.0019 - 0.0039 in.)
Max. Allowable Stem - to - Guide Clearance (Rocking
Method)
Intake Exhaust
0.069 mm (0.0028 in.) 0.098 mm (0.0039 in.)
Valve Lift (Zero Lash)
Intake Exhaust VALVE SPRING
12.00 mm (0.472 in.) 10.90 mm (0.4292 in.)
Free Length (Approx)
Intake Exhaust
48.92 mm (1.9260 in.) 49.81 mm (1.9610 in.)
Spring Force (Valve Closed)
Intake
Exhaust
361.0 - 390.0 N @ 40.12
mm
(81.15 - 87.67 lbs. @
1.5795 in.)
390.0 - 430.0 N @ 40.12
mm
(87.67 - 96.66 lbs. @
1.5795 in.)
DR
DESCRIPTION Spring Force (Valve Open)
SPECIFICATION
Intake
Exhaust
984.0 - 1040.0 N @ 28.12 mm 221.2 - 233.8 lbs. @ 1.107 in.) 965.0 - 1055.0 N @ 28.12 mm 216.9 - 237.1 lbs. @ 1.107 in.)
Intake Exhaust
7.30
7.45
Wire Diameter
Intake and Exhaust
4.77 × 3.80mm
(0.1878 - 0.1496 in.)
Installed Height (Spring Seat to Bottom of Retainer)
Nominal
Intake Exhaust CYLINDER HEAD
40.12 mm (1.579 in.) 40.12 mm (1.579 in.)
Gasket Thickness
(Compressed)
Valve Seat Angle
Valve Seat Runout (MAX) Valve Seat Width
0.7 mm (0.0276 in.)
44.5° - 45.0°
0.051 mm (0.002 in.)
Intake
1.75 - 2.36 mm
(0.0698 - 0.0928 in.)
Exhaust
1.71 - 2.32 mm
(0.0673 - 0.0911 in.)
Guide Bore Diameter
6.975 - 7.00 mm
(Std.)
(0.2747 - 0.2756 in.)
Cylinder Head Warpage
(Flatness)
0.0508 mm (0.002 in.)
OIL PUMP
Clearance Over
Rotors/End Face (MAX)
0.095 mm
(0.0038 in.)
DR ENGINE - 3.7L (Continued)
ENGINE - 3.7L
9 - 15
DESCRIPTION
SPECIFICATION
DESCRIPTION
Cover Out - of -Flat
0.025 mm (0.001 in.)
(MAX)
Inner and Outer Rotor
Thickness
Outer Rotor to pocket (Diametral) clearance
(MAX)
12.02 mm (0.4731 in.) .235 mm (.0093 in.)
Outer Rotor Diameter
85.925 mm (0.400 in.)
(MIN)
Tip Clearance Between
Rotors (MAX)
0.150 mm (0.006 in.)
OIL PRESSURE
At Curb Idle Speed
25 kPa (4 psi)
(MIN)*
@ 3000 rpm
170 - 758 kPa (25 - 110
psi)
* CAUTION: If pressure is zero at curb idle, DO NOT run engine at 3000 rpm.
TORQUE
DESCRIPTION
N·m
Ft.
In.
Camshaft
Non - Oiled Sprocket Bolt Bearing Cap Bolts shaft retaining bolt
Counterbalance
Timing Chain Cover—Bolts Connecting Rod Cap—Bolts
122
11
28
58
27
Lbs.
Lbs.
90
—
—
43
20
—
100
250
— —
Bed Plate—Bolts Crankshaft Damper—Bolt Cylinder Head—Bolts
PLUS 90° TURN
Refer to Procedure
175
—
130
Flexplate—Bolts Engine Mount Bracket to Block—Bolts Rear Mount to Transmission—Bolts Generator Mounting—Bolts
M10 Bolts M8 Bolts
Intake Manifold—Bolts
Oil Pan—Bolts Oil Pan—Drain Plug Oil Pump—Bolts Oil Pump Cover—Bolts Oil Pickup Tube—Bolt and Nut Oil Dipstick Tube to Engine Block—Bolt Oil Fill Tube—Bolts Timing Chain Guide—Bolts Timing Chain Tensioner Arm Hydraulic Tensioner—Bolts Timing Chain Primary Tensioner—Bolts Timing Drive Idler Sprocket— Bolt Thermostat Housing—Bolts Water Pump—Bolts
N·m
95
61
46
Ft.
Lbs.
70
45
In.
Lbs. — —
34
—
40
—
—
54
—
28
250
12
105
Refer to Procedure
for
Tightening Sequence
130
15
—
34
28
250
105
12
28
250
—
25
—
—
—
15
12
28
28
28
28
34
12
58
— — — — — —
25
—
43
130
105
250
250
250
250
—
105
—
Cylinder Head Cover—Bolts Exhaust Manifold—Bolts Exhaust Manifold Heat Shield—Nuts
M11 Bolts Refer M8 Bolts
ToProcedure
—
18
—
105
—
72
12
25
Then loosen 45°
ENGINE - 3.7L
9 - 16
ENGINE - 3.7L (Continued)
SPECIAL TOOLS
DR
SpannerWrench6958
HandleC-4171
AdapterPins8346
RearCrankshaftSealInstaller8349
FrontCrankshaftSealRemover8511
RearCrankshaftSealRemover8506
FrontCrankshaftSealInstaller8348
ConnectingRodGuides8507
DR ENGINE - 3.7L (Continued)
ENGINE - 3.7L
9 - 17
CrankshaftDamperInstaller8512
ChainTensionerPins8514
Puller1026
VALVESPRINGCOMPRESSOR8426
CrankshaftDamperRemovalInsert8513
ChainTensionerWedge8379
ENGINELIFTINGFIXTURE8427
CAMSHAFTHOLDER8428
ENGINE - 3.7L
9 - 18
ENGINE - 3.7L (Continued)
DR
HOLDERSECONDARYCAMSHAFTCHAIN8429
INSTALLER-REMOVER-COUNTERBALANCE
SHAFT8641
Remover,RockerArm8516
ValveSpringTesterC-647
DialIndicatorC-3339
ValveSpringCompressorC-3422-B
IdlerShaftRemover8517
ValveSpringCompressorAdapters8519
DR ENGINE - 3.7L (Continued)
ENGINE - 3.7L
9 - 19
BoreSizeIndicatorC-119
PressureTesterKit7700
Bloc–Chek–KitC-3685–A
OilPressureGaugeC-3292
PistonRingCompressorC-385
ENGINESUPPORTFIXTURE8534
9 - 20
ENGINE - 3.7L
DR
AIR CLEANER ELEMENT REMOVAL
Filter Element Only
Housing removal is not necessary for element (fil-
ter) replacement.
at air cleaner cover.
(1) Loosen clamp (Fig. 3) and disconnect air duct
(2) Pry over 4 spring clips (Fig. 3) from housing
cover (spring clips retain cover to housing).
(3) Release housing cover from locating tabs on
housing (Fig. 3) and remove cover.
(4) Remove air cleaner element (filter) from hous-
(5) Clean inside of housing before replacing ele-
ing.
ment.
Fig.4AIRCLEANERHOUSING
1 - AIR CLEANER HOUSING ASSEMBLY 2 - LOCATING PINS (4)
(3) Pry up 4 spring clips (Fig. 3) and lock cover to
housing.
(4) Install air duct to air cleaner cover and tighten
hose clamp to 3 N·m (30 in. lbs.) torque.
(5) If any other hose clamps were removed from air intake system, tighten them to 3.4 N·m (30 in. lbs.) torque.
(6) If any bolts were removed from air resonator housing or air intake tubing, tighten them to 4.5 N·m (40 in. lbs.) torque.
CYLINDER HEAD - LEFT DIAGNOSIS AND TESTING - CYLINDER HEAD GASKET
A cylinder head gasket leak can be located between adjacent cylinders or between a cylinder and the adjacent water jacket.
leaking between adjacent cylinders are:
Possible indications of the cylinder head gasket † Loss of engine power † Engine misfiring † Poor fuel economy Possible indications of the cylinder head gasket leaking between a cylinder and an adjacent water jacket are:
† Engine overheating † Loss of coolant
Fig.3AIRCLEANERHOUSINGCOVER
1 - CLAMP 2 - AIR DUCT 3 - AIR CLEANER COVER 4 - LOCATING TABS 5 - CLIPS (4)
Housing Assembly
(1) Loosen clamp (Fig. 3) and disconnect air duct
at air cleaner cover.
pins (Fig. 4).
(2) Lift entire housing assembly from 4 locating
INSTALLATION
(1) Install filter element into housing. (2) Position housing cover into housing locating
tabs (Fig. 3).
DR CYLINDER HEAD - LEFT (Continued) † Excessive steam (white smoke) emitting from exhaust † Coolant foaming CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is leaking between adjacent cylinders, follow the proce- dures in Cylinder Compression Pressure Test (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING). An engine cylinder head gasket leaking between adja- cent cylinders will result in approximately a 50–70% reduction in compression pressure.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE ENGINE IS OPERATING WITH COOLANT PRES- SURE CAP REMOVED.
VISUAL TEST METHOD
With the engine cool, remove the coolant pressure cap. Start the engine and allow it to warm up until thermostat opens.
If a large combustion/compression pressure leak
exists, bubbles will be visible in the coolant.
COOLING SYSTEM TESTER METHOD
WARNING: WITH COOLING SYSTEM TESTER IN PLACE, PRESSURE WILL BUILD UP FAST. EXCES- SIVE PRESSURE BUILT UP, BY CONTINUOUS ENGINE OPERATION, MUST BE RELEASED TO A SAFE PRESSURE POINT. NEVER PERMIT PRES- SURE TO EXCEED 138 kPa (20 psi).
Install Cooling System Tester 7700 or equivalent to pressure cap neck. Start the engine and observe the tester’s pressure gauge. If gauge pulsates with every power stroke of a cylinder a combustion pressure leak is evident.
CHEMICAL TEST METHOD
Combustion leaks into the cooling system can also be checked by using Bloc-Chek Kit C-3685-A or equivalent. Perform test following the procedures supplied with the tool kit.
REMOVAL
(1) Disconnect the negative cable from the battery. (2) Raise the vehicle on a hoist. (3) Disconnect the exhaust pipe at the left side
exhaust manifold.
(4) Drain the engine coolant(Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
(5) Lower the vehicle.
ENGINE - 3.7L
9 - 21
(6) Remove the intake manifold(Refer
ENGINE/MANIFOLDS/INTAKE REMOVAL).
MANIFOLD
to 9 -
(7) Remove the master cylinder and booster assem- bly(Refer to 5 - BRAKES/HYDRAULIC/MECHANI- CAL/POWER BRAKE BOOSTER - REMOVAL).
(8) Remove the cylinder head cover(Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - REMOVAL).
(9) Remove the fan shroud and fan blade assem- bly(Refer to 7 - COOLING/ENGINE/RADIATOR FAN - REMOVAL).
(10) Remove accessory drive belt(Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS - REMOVAL).
(11) Remove the power steering pump and set
aside.
(12) Rotate the crankshaft until the damper tim- ing mark is aligned with TDC indicator mark (Fig. 5).
Fig.5EngineTopDeadCenter
1 - TIMING CHAIN COVER 2 - CRANKSHAFT TIMING MARKS
(13) Verify the V6 mark on the camshaft sprocket is at the 12 o’clock position (Fig. 6). Rotate the crank- shaft one turn if necessary.
(14) Remove the crankshaft damper(Refer to 9 - ENGINE/ENGINE BLOCK/VIBRATION DAMPER - REMOVAL).
(15) Remove the timing chain cover(Refer to 9 - ENGINE/VALVE TIMING/TIMING BELT / CHAIN COVER(S) - REMOVAL).
ENGINE - 3.7L
9 - 22
CYLINDER HEAD - LEFT (Continued)
DR
Fig.6CAMSHAFTSPROCKETV6MARKS(#1TDC,Exhauststroke)
1 - LEFT CYLINDER HEAD 2 - RIGHT CYLINDER HEAD
(16) Lock the secondary timing chains to the idler
NOTE: Mark the secondary timing chain prior to removal to aid in installation.
(17) Mark the secondary timing chain, one link on each side of the V6 mark on the camshaft drive gear. (18) Remove the left side secondary chain ten-
sioner. Refer to Timing Chain and Sprockets.
(19) Remove the cylinder head access plug (Fig. 8).
Fig.7UsingSpecialTool8429
Fig.8CylinderHeadAccessPlugs
1 - SPECIAL TOOL 8429
2 - CAMSHAFT CHAIN 3 - CRANKSHAFT TIMING GEAR
sprocket using Special Tool 8429 Timing Chain Hold- ing Fixture (Fig. 7).
1 - RIGHT CYLINDER HEAD ACCESS PLUG 2 - LEFT CYLINDER HEAD ACCESS PLUG
(20) Remove
chain guide(Refer to 9 - ENGINE/VALVE TIMING/TIMING BELT/CHAIN AND SPROCKETS - REMOVAL).
secondary
side
left
the
DR CYLINDER HEAD - LEFT (Continued)
ENGINE - 3.7L
9 - 23
(21) Remove the retaining bolt and the camshaft
drive gear.
(1) Clean the cylinder head and cylinder block
mating surfaces (Fig. 10).
CAUTION: Do not allow the engine to rotate. Severe damage to the valve train can occur.
CAUTION: Do not overlook the four smaller bolts at the front of the cylinder head. Do not attempt to remove the cylinder head without removing these four bolts.
NOTE: The cylinder head is attached to the cylinder block with twelve bolts.
(22) Remove the cylinder head retaining bolts. (23) Remove the cylinder head and gasket. Discard
the gasket.
CAUTION: Do not lay the cylinder head on its gas- ket sealing surface, due to the design of the cylin- der head gasket any distortion to the cylinder head sealing surface may prevent the gasket from prop- erly sealing resulting in leaks.
INSTALLATION
NOTE: The cylinder head bolts are tightened using a torque plus angle procedure. The bolts must be examined BEFORE reuse. If the threads are necked down the bolts should be replaced.
Necking can be checked by holding a straight edge against the threads. If all the threads do not contact the scale, the bolt should be replaced (Fig. 9).
Fig.10ProperToolUsageForSurfacePreparation 1 - PLASTIC/WOOD SCRAPER
(2) Position the new cylinder head gasket on the
locating dowels.
CAUTION: When installing cylinder head, use care not damage the tensioner arm or the guide arm.
(3) Position the cylinder head onto the cylinder block. Make sure the cylinder head seats fully over the locating dowels.
NOTE: The four smaller cylinder head mounting bolts require sealant to be added to them before installing. Failure to do so may cause leaks.
(4) Lubricate the cylinder head bolt threads with
clean engine oil and install the eight M11 bolts.
(5) Coat the four M8 cylinder head bolts with Mopart Lock and Seal Adhesive then install the bolts.
Fig.9CheckingCylinderHeadBoltsforStretching
(Necking)
1 - STRETCHED BOLT 2 - THREADS ARE NOT STRAIGHT ON LINE 3 - THREADS ARE STRAIGHT ON LINE 4 - UNSTRETCHED BOLT
CAUTION: When cleaning cylinder head and cylin- der block surfaces, DO NOT use a metal scraper because the surfaces could be cut or ground. Use only a wooden or plastic scraper.
NOTE: The cylinder head bolts are tightened using an angle torque procedure, however, the bolts are not a torque-to-yield design.
ing steps and torque values:
(6) Tighten the bolts in sequence using the follow- † Step 1: Tighten bolts 1–8, 27 N·m (20 ft. lbs.). † Step 2: Verify that bolts 1–8, all reached 27 N·m (20 ft. lbs.), by repeating step-1 without loosening the bolts. Tighten bolts 9 thru 12 to 14 N·m (10 ft. lbs.). † Step 3: Tighten bolts 1–8, 90 degrees (Fig. 11).
ENGINE - 3.7L
9 - 24
CYLINDER HEAD - LEFT (Continued)
† Step 4: Tighten bolts 1–8, 90 degrees, again.
Tighten bolts 9–12, 26 N·m (19 ft. lbs.)
Fig.11CylinderheadTighteningSequence
* - INDICATES SEALANT ON THREADS
(7) Position the secondary chain onto the camshaft drive gear, making sure one marked chain link is on either side of the V6 mark on the gear then using Special Tool 8428 Camshaft Wrench, position the gear onto the camshaft.
CAUTION: Remove excess oil from camshaft sprocket retaining bolt before reinstalling bolt. Fail- ure to do so may cause over-torqueing of bolt resulting in bolt failure.
(8) Install the camshaft drive gear retaining bolt. (9) Install the left side secondary chain guide(Re- fer to 9 - ENGINE/VALVE TIMING/TIMING BELT/ CHAIN AND SPROCKETS - INSTALLATION).
(10) Install the cylinder head access plug. (11) Re-set and Install
the left side secondary chain tensioner(Refer to 9 - ENGINE/VALVE TIM- ING/TIMING BELT/CHAIN AND SPROCKETS - INSTALLATION).
(12) Remove Special Tool 8429. (13) Install the timing chain cover(Refer to 9 - ENGINE/VALVE TIMING/TIMING BELT / CHAIN COVER(S) - INSTALLATION).
(14) Install the crankshaft damper(Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
INSTALLATION). Tighten damper bolt 175 N·m (130
Ft. Lbs.).
(15) Install the power steering pump.
DR
(16) Install the fan blade assembly and fan shrou- d(Refer to 7 - COOLING/ENGINE/RADIATOR FAN - INSTALLATION).
(17) Install the cylinder head cover(Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - INSTALLATION).
(18) Reinstall
the master cylinder and booster assembly(Refer to 5 - BRAKES/HYDRAULIC/ME- CHANICAL/POWER BRAKE BOOSTER - INSTAL- LATION).
(19) Install
the intake manifold(Refer
MANIFOLD
to 9 -
ENGINE/MANIFOLDS/INTAKE INSTALLATION).
(20) Refill the cooling system(Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
(21) Raise the vehicle. (22) Install the exhaust pipe onto the left exhaust
manifold.
(23) Lower the vehicle. (24) Connect the negative cable to the battery. (25) Start the engine and check for leaks.
CAMSHAFT(S) DESCRIPTION
The camshafts consist of powdered metal steel lobes which are sinter-bonded to a steel tube. Four bearing journals are machined into the camshaft. Camshaft end play is controlled by two thrust walls that border the nose piece journal. Engine oil enters the hollow camshafts at the third journal and lubri- cates every intake lobe rocker through a drilled pas- sage in the intake lobe.
REMOVAL
CAUTION: When the timing chain is removed and the cylinder heads are still installed, DO NOT force- fully rotate the camshafts or crankshaft indepen- dently of each other. Severe valve and/or piston damage can occur.
CAUTION: When removing the cam sprocket, timing chains or camshaft, Failure to use Special Tool 8379 will result in hydraulic tensioner ratchet over extension, requiring timing chain cover removal to reset the tensioner ratchet.
(1) Remove cylinder head cover(Refer
to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - REMOVAL).
(2) Set engine to TDC cylinder #1,
camshaft
sprocket V6 marks at the 12 o’clock position.
DR CAMSHAFT(S) (Continued)
(3) Mark one link on the secondary timing chain on both sides of the V6 mark on the camshaft sprocket to aid in installation.
CAUTION: Do not hold or pry on the camshaft tar- get wheel (Located on the right side camshaft sprocket) for any reason, Severe damage will occur to the target wheel resulting in a vehicle no start condition.
(4) Loosen but DO NOT remove the camshaft sprocket retaining bolt. Leave the bolt snug against the sprocket.
NOTE: The timing chain tensioners must be secured prior to removing the camshaft sprockets. Failure to secure tensioners will allow the tension- ers to extend, requiring timing chain cover removal in order to reset tensioners.
CAUTION: Do not force wedge past the narrowest point between the chain strands. Damage to the tensioners may occur.
(5) Position Special Tool 8379 timing chain wedge between the timing chain strands, tap the tool to securely wedge the timing chain against the ten- sioner arm and guide (Fig. 12).
Fig.12SECURINGTIMINGCHAINTENSIONERS
USINGTIMINGCHAINWEDGE—Typical
1 - SPECIAL TOOL 8379
2 - CAMSHAFT SPROCKET
3 - CAMSHAFT SPROCKET BOLT
4 - CYLINDER HEAD
(6) Hold the camshaft with Special Tool 8428 Cam- shaft Wrench, while removing the camshaft sprocket bolt and sprocket (Fig. 13).
ENGINE - 3.7L
9 - 25
Fig.13SpecialTool8428
1 - Camshaft hole
2 - Special Tool 8428
(7) Using Special Tool 8428 Camshaft Wrench, gently allow the camshaft to rotate 5° clockwise until the camshaft is in the neutral position (no valve load).
(8) Starting at the outside working inward, loosen the camshaft bearing cap retaining bolts 1/2 turn at a time. Repeat until all load is off the bearing caps.
CAUTION: DO NOT STAMP OR STRIKE THE CAM- SHAFT BEARING CAPS. SEVERE DAMAGE WILL OCCUR TO THE BEARING CAPS.
NOTE: When the camshaft is removed the rocker arms may slide downward, mark the rocker arms before removing camshaft.
(9) Remove the camshaft bearing caps and the
camshaft.
INSTALLATION
(1) Lubricate camshaft journals with clean engine
oil.
NOTE: Position the left side camshaft so that the camshaft sprocket dowel is near the 1 o’clock posi- tion, This will place the camshaft at the neutral position easing the installation of the camshaft bearing caps.
(2) Position the camshaft into the cylinder head.
ENGINE - 3.7L
9 - 26
CAMSHAFT(S) (Continued)
(3) Install the camshaft bearing caps, hand tighten
the retaining bolts.
NOTE: Caps should be installed so that the stamped numbers on the caps are in numerical order, ( 1 thru 4 ) from the front to the rear of the engine. All caps should be installed so that the stamped arrows on the caps point toward the front of the engine.
(4) Working in 1⁄2 turn increments, tighten the bearing cap retaining bolts starting with the middle cap working outward (Fig. 14).
DR
(10) Using Special Tool 6958 spanner wrench with adapter pins 8346, torque the camshaft sprocket retaining bolt to 122 N·m (90 ft. lbs.).
(11) Install the cylinder head cover(Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - INSTALLATION).
CYLINDER HEAD COVER(S) DESCRIPTION
The cylinder head covers are made of single layer stamped steel, and are not interchangable from side- to-side (Fig. 15).
Fig.14CAMSHAFTBEARINGCAPSTIGHTENING (5) Torque the camshaft bearing cap retaining
bolts to 11 N·m (100 in. lbs.).
(6) Position the camshaft drive gear into the tim- ing chain aligning the V6 mark between the two marked chain links (Two links marked during remov- al).
(7) Using Special Tool 8428 Camshaft Wrench, the camshaft sprocket in the camshaft
rotate the camshaft until dowel sprocket. Install the sprocket onto the camshaft.
is aligned with the slot
CAUTION: Remove excess oil from camshaft sprocket bolt. Failure to do so can cause bolt over- torque resulting in bolt failure.
(8) Remove excess oil from bolt, then install the
camshaft sprocket retaining bolt and hand tighten.
(9) Remove Special Tool 8379 timing chain wedge.
Fig.15CYLINDERHEADCOVERS
1 - LEFT SIDE CYLINDER HEAD COVER 2 - RIGHT SIDE CYLINDER HEAD COVER
REMOVAL
(1) Disconnect negative cable from battery. (2) Remove the resonator assemble and air inlet
hose.
cover.
injector harness.
(3) Disconnect injector connectors and un-clip the
(4) Route injector harness in front of cylinder head
(5) Disconnect
the left side breather tube and
remove the breather tube.
DR CYLINDER HEAD COVER(S) (Continued)
ENGINE - 3.7L
9 - 27
(6) Remove the cylinder head cover mounting bolts
(Fig. 16).
(7) Remove cylinder head cover and gasket.
NOTE: The gasket may be used again, providing no cuts, tears, or deformation has occurred.
Fig.16CYLINDERHEADCOVER-TYPICAL
1 - SCREWS 2 - CYLINDER HEAD COVER
INSTALLATION
CAUTION: Do not use harsh cleaners to clean the cylinder head covers. Severe damage to covers may occur.
NOTE: The gasket may be used again, provided no cuts, tears, or deformation has occurred.
(1) Clean cylinder head cover and both sealing sur-
faces. Inspect and replace gasket as necessary.
(2) Tighten cylinder head cover bolts and double
ended studs to 12 N·m (105 in. lbs.).
(3) Install left side breather and connect breather
tube.
(4) Connect injector electrical connectors and injec-
tor harness retaining clips.
(5) Install the resonator and air inlet hose. (6) Connect negative cable to battery.
INTAKE/EXHAUST VALVES & SEATS DESCRIPTION
The valves are made of heat resistant steel and have chrome plated stems to prevent scuffing. Each valve is actuated by a roller rocker arm which pivots on a stationary lash adjuster. All valves use three bead lock keepers to retain the springs and promote valve rotation.
STANDARD PROCEDURE - REFACING
NOTE: Valve seats that are worn or burned can be reworked, provided that correct angle and seat width are maintained. Otherwise the cylinder head must be replaced.
NOTE: When refacing valves and valve seats, it is important that the correct size valve guide pilot be used for reseating stones. A true and complete sur- face must be obtained.
(1) Using a suitable dial
indicator measure the center of the valve seat Total run out must not exceed 0.051 mm (0.002 in).
(2) Apply a small amount of Prussian blue to the valve seat, insert the valve into the cylinder head, while applying light pressure on the valve rotate the valve. Remove the valve and examine the valve face. If the blue is transferred below the top edge of the valve face, lower the valve seat using a 15 degree stone. If the blue is transferred to the bottom edge of the valve face, raise the valve seat using a 65 degree stone.
(3) When the seat is properly positioned the width
of the intake seat must be 1.75 – 2.36 mm (0.0689 –
0.0928 in.) and the exhaust seat must be 1.71 – 2.32
mm (0.0673 – 0.0911 in.).
(4) Check the valve spring installed height after refacing the valve and seat. The installed height for both intake and exhaust valve springs must not exceed 40.74 mm (1.6039 in.).
ENGINE - 3.7L
9 - 28
INTAKE/EXHAUST VALVES & SEATS (Continued)
(5) The valve seat and valve face must maintain a
face angle of 44.5 – 45 degrees angle (Fig. 17).
DR
Fig.17ValveAssemblyConfiguration
1 - CAMSHAFT
2 - SPECIAL TOOL 8516
Fig.18RockerArmRemoval
1 - VALVE LOCKS (3–BEAD) 2 - RETAINER 3 - VALVE STEM OIL SEAL 4 - INTAKE VALVE 5 - EXHAUST VALVE 6 - VALVE SPRING
REMOVAL
NOTE: The cylinder heads must be removed in order to perform this procedure.
(1) Remove rocker arms and lash adjusters(Refer to 9 - ENGINE/CYLINDER HEAD/ROCKER ARM / ADJUSTER ASSY - REMOVAL). (Fig. 18).
(2) Remove the camshaft bearing caps and the
camshaft.
NOTE: All six valve springs and valves are removed in the same manner; this procedure only covers one valve and valve spring.
(3) Using Special Tool C-3422–B or C-3422–C
tool 8519
Valve Spring Compressor and Special Adapter, compress the valve spring.
NOTE: It may be necessary to tap the top of the valve spring to loosen the spring retainers locks enough to be removed.
(4) Remove the two spring retainer lock halves.
NOTE: the valve spring is under tension use care when releasing the valve spring compressor.
(5) Remove the valve spring compressor. (6) Remove the spring retainer, and the spring.
NOTE: Check for sharp edges on the keeper grooves. Remove any burrs from the valve stem before removing the valve from the cylinder head.
(7) Remove the valve from the cylinder head.
NOTE: The valve stem seals are common between intake and exhaust.
(8) Remove the valve stem seal. Mark the valve for
proper installation.
TESTING VALVE SPRINGS
NOTE: Whenever the valves are removed from the cylinder head it the valve springs be inspected and tested for reuse.
is recommended that
Inspect the valve springs for physical signs of wear or damage. Turn table of tool C-647 until surface is in line with the 40.12 mm (1.579 in.) mark on the threaded stud and the zero mark on the front. Place spring over the stud on the table and lift compress- ing lever to set tone device. 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 measurements are indicated on the table for finer
DR INTAKE/EXHAUST VALVES & SEATS (Continued)
adjustments. Refer to Specifications Section to obtain specified height and allowable tensions. Replace any springs that do not meet specifications (Fig. 19).
ENGINE - 3.7L
9 - 29
Fig.19TestingValveSprings
1 - SPECIAL TOOL C-647
INSTALLATION
(1) coat the valve stem with clean engine oil and
insert it into the cylinder head.
(2) Install the valve stem seal. make sure the seal is fully seated and that the garter spring at the top of the seal is intact.
(3) Install the spring and the spring retainer (Fig.
20).
(4) Using the valve spring compressor, compress the spring and install the two valve spring retainer halves.
(5) Release the valve spring compressor and make sure the two spring retainer halves and the spring retainer are fully seated.
(6) lubricate the camshaft
then Position the camshaft
journal with clean engine oil (with the sprocket dowel on the left camshaft at 11 o’clock and the right camshaft at 12 o’clock), then position the camshaft bearing caps.
(7) Install
the camshaft bearing cap retaining
bolts. Tighten the bolts 9–13 N·m (100 in. lbs.) in 1⁄2
turn increments in the sequence shown (Fig. 21).
(8) Position the hydraulic
lash adjusters and rocker arms(Refer to 9 - ENGINE/CYLINDER HEAD/ROCKER ARM / ADJUSTER ASSY - INSTAL- LATION).
Fig.20ValveAssemblyConfiguration
1 - VALVE LOCKS (3–BEAD) 2 - RETAINER 3 - VALVE STEM OIL SEAL 4 - INTAKE VALVE 5 - EXHAUST VALVE 6 - VALVE SPRING
Fig.21CamshaftBearingCapsTightening
Sequence
DR
9 - 30
ENGINE - 3.7L
ROCKER ARM DESCRIPTION
The rocker arms are steel stampings with an inte-
gral roller bearing. The rocker arms incorporate a 2.8
mm (0.11 inch) oil hole in the lash adjuster socket for
roller and camshaft lubrication.
REMOVAL
NOTE: Disconnect the battery negative cable to pre- vent accidental starter engagement.
(1) Remove the cylinder head cover (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - REMOVAL).
(2) For rocker arm removal on cylinder #4, Rotate the crankshaft until cylinder #1 is at BDC intake stroke.
(3) For rocker arm removal on cylinder #1, Rotate the crankshaft until cylinder #1 is at BDC combus- tion stroke.
(4) For rocker arm removal on cylinders #3 and #5, Rotate the crankshaft until cylinder #1 is at TDC exhaust stroke.
(5) For rocker arm removal on cylinders #2 and #6, Rotate the crankshaft until cylinder #1 is at TDC ignition stroke.
(6) Using special tool 8516 Rocker Arm Remover, press downward on the valve spring, remove rocker arm (Fig. 22).
INSTALLATION
CAUTION: Make sure the rocker arms are installed with the concave pocket over the lash adjusters. Failure to do so may cause severe damage to the rocker arms and/or lash adjusters.
NOTE: Coat the rocker arms with clean engine oil prior to installation.
(1) For rocker arm installation on cylinders #4, Rotate the crankshaft until cylinder #1 is at BDC intake stroke.
(2) For rocker arm installation on cylinder #1, Rotate the crankshaft until cylinder #1 is at BDC combustion stroke.
(3) For rocker arm installation on cylinders #3 and #5, Rotate the crankshaft until cylinder #1 is at TDC exhaust stroke.
(4) For rocker arm installation on cylinders #2 and #6, Rotate the crankshaft until cylinder #1 is at TDC ignition stroke.
(5) Using special tool 8516 press downward on the
valve spring, install rocker arm (Fig. 23).
Fig.22RockerArm-Removal
1 - CAMSHAFT
2 - SPECIAL TOOL 8516
Fig.23RockerArm-Installation
1 - CAMSHAFT
2 - SPECIAL TOOL 8516
(6) Install the cylinder head cover (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - INSTALLATION).
DR
ENGINE - 3.7L
9 - 31
VALVE GUIDE SEALS DESCRIPTION
The valve guide seals are made of rubber and incorporate an integral steel valve spring seat. The integral garter spring maintains consistent lubrica- tion control to the valve stems.
VALVE SPRINGS DESCRIPTION
The valve springs are made from high strength chrome silicon steel. The springs are NOT common for intake and exhaust applications. The valve spring seat is integral with the valve stem seal, which is a positive type seal to control lubrication.
REMOVAL
(1) Remove the cylinder head cover(Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - REMOVAL).
(2) Using Special Tool 8516 Valve Spring Compres- sor, remove the rocker arms and the hydraulic lash adjusters.
(3) Remove the spark plug for the cylinder the
valve spring and seal are to be removed from.
(4) Apply shop air to the cylinder to hold the
valves in place when the spring is removed.
NOTE: All six valve springs and seals are removed in the same manner; this procedure only covers one valve seal and valve spring.
(5) Using Special Tool 8387 Valve Spring Compres-
sor, compress the valve spring.
NOTE: It may be necessary to tap the top of the valve spring to loosen the spring retainers locks enough to be removed.
(6) Remove the two spring retainer lock halves.
NOTE: the valve spring is under tension use care when releasing the valve spring compressor.
(7) Remove the valve spring compressor.
NOTE: The valve springs are NOT common between intake and exhaust.
(8) Remove the spring retainer, and the spring. (9) Remove the valve stem seal.
NOTE: The valve stem seals are common between intake and exhaust.
INSTALLATION
NOTE: All six valve springs and seals are removed in the same manner; this procedure only covers one valve seal and valve spring.
(1) Apply shop air to the cylinder to hold the
valves in place while the spring is installed.
NOTE: The valve stem seals are common between intake and exhaust.
(2) Install the valve stem seal.
NOTE: The valve springs are NOT common between intake and exhaust.
(3) Install the spring retainer, and the spring. (4) Using Special Tool 8387 Valve Spring Compres-
sor, compress the valve spring.
(5) Install the two spring retainer lock halves.
NOTE: the valve spring is under tension use care when releasing the valve spring compressor.
(6) Remove the valve spring compressor. (7) Disconnect the shop air to the cylinder. (8) Install the spark plug for the cylinder the valve
spring and seal was installed on.
(9) Using Special Tool 8516 Valve Spring Compres- sor, install the rocker arms and the hydraulic lash adjusters.
(10) Install the cylinder head cover(Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - INSTALLATION).
CYLINDER HEAD - RIGHT DIAGNOSIS AND TESTING - HYDRAULIC LASH ADJUSTER
A tappet-like noise may be produced from several
items. Check the following items.
(1) Engine oil level too high or too low. This may cause aerated oil to enter the adjusters and cause them to be spongy.
(2) Insufficient running time after rebuilding cylin- der head. Low speed running up to 1 hour may be required.
(3) Turn engine off and let set for a few minutes before restarting. Repeat this several times after engine has reached normal operating temperature.
(4) Low oil pressure. (5) The oil restrictor in cylinder head gasket or the oil passage to the cylinder head is plugged with debris.
ENGINE - 3.7L
9 - 32
CYLINDER HEAD - RIGHT (Continued)
DR
(6) Air ingested into oil due to broken or cracked
oil pump pick up.
(7) Worn valve guides. (8) Rocker arm ears
retainer.
contacting valve
spring
(9) Rocker arm loose, adjuster stuck or at maxi-
mum extension and still leaves lash in the system.
(10) Oil leak or excessive cam bore wear in cylin-
der head.
(11) Faulty lash adjuster. a. Check lash adjusters
sponginess while installed in cylinder head and cam on camshaft at base circle. Depress part of rocker arm over adjuster. Normal adjusters should feel very firm. Spongy adjusters can be bottomed out easily.
for
b. Remove suspected lash adjusters, and replace. c. Before installation, make sure adjusters are at least partially full of oil. This can be verified by little or no plunger travel when lash adjuster is depressed.
REMOVAL
(1) Disconnect battery negative cable. (2) Raise the vehicle on a hoist. (3) Disconnect the exhaust pipe at the right side
exhaust manifold.
(4) Drain the engine coolant(Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
(5) Lower the vehicle. (6) Remove the intake manifold(Refer
ENGINE/MANIFOLDS/INTAKE REMOVAL).
MANIFOLD
to 9 -
(7) Remove the cylinder head cover(Refer to 9 -
ENGINE/CYLINDER HEAD - REMOVAL).
(8) Remove the fan shroud(Refer to 7 - COOLING/
ENGINE/RADIATOR FAN - REMOVAL).
(9) Remove oil fill housing from cylinder head. (10) Remove accessory drive belt(Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS - REMOVAL).
(11) Rotate the crankshaft until the damper timing
mark is aligned with TDC indicator mark.
(12) Verify the V6 mark on the camshaft sprocket is at the 12 o’clock position. Rotate the crankshaft one turn if necessary.
(13) Remove the crankshaft damper(Refer to 9 - ENGINE/ENGINE BLOCK/VIBRATION DAMPER - REMOVAL).
(14) Remove the timing chain cover(Refer to 9 - ENGINE/VALVE TIMING/TIMING BELT / CHAIN COVER(S) - REMOVAL).
(15) Lock the secondary timing chains to the idler sprocket using Special Tool 8429 Timing Chain Hold- ing Fixture.
NOTE: Mark the secondary timing chain prior to removal to aid in installation.
(16) Mark the secondary timing chain, one link on each side of the V6 mark on the camshaft drive gear. (17) Remove the right side secondary chain ten- sioner(Refer to 9 - ENGINE/VALVE TIMING/TIM- ING BELT/CHAIN AND SPROCKETS - REMOVAL).
(18) Remove the cylinder head access plug. (19) Remove secondary
chain guide(Refer to 9 - ENGINE/VALVE TIMING/TIMING BELT/CHAIN AND SPROCKETS - REMOVAL).
right
side
the
CAUTION: The nut on the right side camshaft sprocket should not be removed for any reason, as the sprocket and camshaft sensor target wheel is serviced as an assembly. If the nut was removed retorque nut to 5 N·m (44 in. lbs.).
(20) Remove the retaining bolt and the camshaft
drive gear.
CAUTION: Do not allow the engine to rotate. severe damage to the valve train can occur.
CAUTION: Do not overlook the four smaller bolts at the front of the cylinder head. Do not attempt to remove the cylinder head without removing these four bolts.
CAUTION: Do not hold or pry on the camshaft tar- get wheel for any reason. A damaged target wheel can result in a vehicle no start condition.
NOTE: The cylinder head is attached to the cylinder block with twelve bolts.
(21) Remove the cylinder head retaining bolts. (22) Remove the cylinder head and gasket. Discard
the gasket.
CAUTION: Do not lay the cylinder head on its gas- ket sealing surface, do to the design of the cylinder head gasket any distortion to the cylinder head sealing surface may prevent the gasket from prop- erly sealing resulting in leaks.
INSTALLATION
NOTE: The cylinder head bolts are tightened using a torque plus angle procedure. The bolts must be examined BEFORE reuse. If the threads are necked down the bolts should be replaced.
Necking can be checked by holding a straight edge against the threads (Fig. 24). If all the threads do not contact the scale, the bolt should be replaced.
DR CYLINDER HEAD - RIGHT (Continued)
ENGINE - 3.7L
9 - 33
(3) Position the cylinder head onto the cylinder block. Make sure the cylinder head seats fully over the locating dowels.
NOTE: The four M8 cylinder head mounting bolts require sealant to be added to them before install- ing. Failure to do so may cause leaks.
Fig.24CheckingCylinderHeadBoltsforStretching
(Necking)
1 - STRETCHED BOLT 2 - THREADS ARE NOT STRAIGHT ON LINE 3 - THREADS ARE STRAIGHT ON LINE 4 - UNSTRETCHED BOLT
CAUTION: When cleaning cylinder head and cylin- der block surfaces, DO NOT use a metal scraper because the surfaces could be cut or ground. Use only a wooden or plastic scraper.
(1) Clean the cylinder head and cylinder block
mating surfaces (Fig. 25).
(4) Lubricate the cylinder head bolt threads with
clean engine oil and install the eight M10 bolts.
(5) Coat the four M8 cylinder head bolts with Mopar Lock and Seal Adhesive then install the bolts.
NOTE: The cylinder head bolts are tightened using an angle torque procedure, however, the bolts are not a torque-to-yield design.
ing steps and torque values:
(6) Tighten the bolts in sequence using the follow- † Step 1: Tighten bolts 1–8, 27 N·m (20 ft. lbs.). † Step 2: Verify that bolts 1–8, all reached 27 N·m (20 ft. lbs.), by repeating step-1 without loosening the bolts. Tighten bolts 9 thru 12 to 14 N·m (10 ft. lbs.). † Step 3: Tighten bolts 1–8, 90 degrees (Fig. 26). † Step 4: Tighten bolts 1–8, 90 degrees, again.
Tighten bolts 9–12, 26 N·m (19 ft. lbs.)
Fig.25ProperToolUsageForSurfacePreparation 1 - PLASTIC/WOOD SCRAPER
(2) Position the new cylinder head gasket on the
locating dowels.
CAUTION: When installing cylinder head, use care not damage the tensioner arm or the guide arm.
Fig.26CylinderHeadTighteningSequence
* - INDICATES SEALANT ON THREADS
CAUTION: The nut on the right side camshaft sprocket should not be removed for any reason, as the sprocket and camshaft sensor target wheel is serviced as an assembly. If the nut was removed retorque nut to 5 ft. lbs.( 60 in. lbs.).
ENGINE - 3.7L
9 - 34
CYLINDER HEAD - RIGHT (Continued)
(7) Position the secondary chain onto the camshaft drive gear, making sure one marked chain link is on either side of the V6 mark on the gear then using Special Tool 8428 Camshaft Wrench, position the gear onto the camshaft.
CAUTION: Remove excess oil from camshaft sprocket retaining bolt before reinstalling bolt. Fail- ure to do so may cause over-torquing of bolt result- ing in bolt failure.
(8) Install the camshaft drive gear retaining bolt. (9) Install the right side secondary chain guide(Re- fer to 9 - ENGINE/VALVE TIMING/TIMING BELT/ CHAIN AND SPROCKETS - INSTALLATION).
(10) Install the cylinder head access plug. (11) Re-set and install the right side secondary chain tensioner(Refer to 9 - ENGINE/VALVE TIM- ING/TIMING BELT/CHAIN AND SPROCKETS - INSTALLATION).
(12) Remove Special Tool 8429. (13) Install the timing chain cover(Refer to 9 - ENGINE/VALVE TIMING/TIMING BELT / CHAIN COVER(S) - REMOVAL).
(14) Install the crankshaft damper(Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
INSTALLATION). Tighten damper bolt 175 N·m (130
Ft. Lbs.).
(15) Install accessory drive belt(Refer to 7 - COOL- ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL- LATION).
(16) Install the fan shroud(Refer to 7 - COOLING/
ENGINE/RADIATOR FAN - INSTALLATION).
(17) Install the cylinder head cover(Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - INSTALLATION).
(18) Install
the intake manifold(Refer
MANIFOLD
to 9 -
ENGINE/MANIFOLDS/INTAKE INSTALLATION).
(19) Install oil fill housing onto cylinder head. (20) Refill the cooling system(Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
(21) Raise the vehicle. (22) Install
exhaust manifold.
the exhaust pipe onto the right
(23) Lower the vehicle. (24) Reconnect battery negative cable. (25) Start the engine and check for leaks.
CAMSHAFT(S) DESCRIPTION
The camshafts consist of powdered metal steel lobes which are sinter-bonded to a steel tube. Four bearing journals are machined into the camshaft. Camshaft end play is controlled by two thrust walls
DR
that border the nose piece journal. Engine oil enters the hollow camshafts at the third journal and lubri- cates every intake lobe rocker through a drilled pas- sage in the intake lobe.
REMOVAL
CAUTION: When the timing chain is removed and the cylinder heads are still installed, DO NOT force- fully rotate the camshafts or crankshaft indepen- dently of each other. Severe valve and/or piston damage can occur.
CAUTION: When removing the cam sprocket, timing
chains or camshaft, Failure to use special tool 8379
will result in hydraulic tensioner ratchet over exten-
sion, Requiring timing chain cover removal to re-set
the tensioner ratchet.
(1) Remove the cylinder head cover(Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - REMOVAL).
(2) Set engine to TDC cylinder #1,
camshaft
sprocket V6 marks at the 12 o’clock position.
(3) Mark one link on the secondary timing chain on both sides of the V6 mark on the camshaft sprocket to aid in installation.
CAUTION: Do not hold or pry on the camshaft tar- get wheel for any reason, Severe damage will occur to the target wheel. A damaged target wheel could cause a vehicle no start condition.
(4) Loosen but DO NOT remove the camshaft sprocket retaining bolt. Leave bolt snug against sprocket.
NOTE: The timing chain tensioners must be secured prior to removing the camshaft sprockets. Failure to secure tensioners will allow the tension- ers to extend, requiring timing chain cover removal in order to reset tensioners.
CAUTION: Do not force wedge past the narrowest point between the chain strands. Damage to the tensioners may occur.
(5) Position Special Tool 8379 timing chain wedge between the timing chain strands. Tap the tool to securely wedge the timing chain against the ten- sioner arm and guide.
(6) Remove the camshaft position sensor. (7) Hold the camshaft with Special Tool 8428 Cam- shaft Wrench, while removing the camshaft sprocket bolt and sprocket.
DR CAMSHAFT(S) (Continued)
(8) Starting at the outside working inward, loosen the camshaft bearing cap retaining bolts 1/2 turn at a time. Repeat until all load is off the bearing caps.
CAUTION: DO NOT STAMP OR STRIKE THE CAM- SHAFT BEARING CAPS. SEVERE DAMAGE WILL OCCUR TO THE BEARING CAPS.
NOTE: When the camshaft is removed the rocker arms may slide downward, mark the rocker arms before removing camshaft.
(9) Remove the camshaft bearing caps and the
camshaft.
INSTALLATION
(1) Lubricate camshaft journals with clean engine
oil.
NOTE: Position the right side camshaft so that the camshaft sprocket dowel is near the 10 o’clock position, This will place the camshaft at the neutral position easing the installation of the camshaft bearing caps.
(2) Position the camshaft into the cylinder head. (3) Install the camshaft bearing caps, hand tighten
the retaining bolts.
NOTE: Caps should be installed so that the stamped numbers on the caps are in numerical order, ( 1 thru 4 ) from the front to the rear of the engine. All caps should be installed so that the stamped arrows on the caps point toward the front of the engine.
(4) Working in 1/2 turn increments, tighten the bearing cap retaining bolts starting with the middle cap working outward (Fig. 27).
(5) Torque the camshaft bearing cap retaining
bolts to 11 N·m (100 in. lbs.).
(6) Position the camshaft drive gear into the tim- ing chain aligning the V6 mark between the two marked chain links (Two links marked during remov- al).
(7) Using Special Tool 8428 Camshaft Wrench, the camshaft sprocket in the camshaft
rotate the camshaft until dowel sprocket. Install the sprocket onto the camshaft.
is aligned with the slot
CAUTION: Remove excess oil from camshaft sprocket bolt. Failure to do so can cause bolt over- torque resulting in bolt failure.
(8) Remove excess oil from camshaft sprocket bolt, then install the camshaft sprocket retaining bolt and hand tighten.
ENGINE - 3.7L
9 - 35
Fig.27CAMSHAFTBEARINGCAPSTIGHTENING (9) Remove timing chain wedge special tool 8379. (10) Using Special Tool 6958 spanner wrench with adapter pins 8346, torque the camshaft sprocket retaining bolt to 122 N·m (90 ft. lbs.).
(11) Install the camshaft position sensor. (12) Install the cylinder head cover(Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - INSTALLATION).
CYLINDER HEAD COVER(S) REMOVAL
(1) Disconnect battery negative cable. (2) Remove air cleaner assembly, resonator assem-
bly and air inlet hose.
(3) Drain cooling system, below the level of the heater hoses(Refer to 7 - COOLING - STANDARD PROCEDURE).
(4) Remove accessory drive belt(Refer to 7 - COOL- ING/ACCESSORY DRIVE/DRIVE BELTS - REMOV- AL).
(5) Remove air conditioning compressor retaining
bolts and move compressor to the left.
(6) Remove heater hoses. (7) Disconnect injector and ignition coil connectors. (8) Disconnect and remove positive crankcase ven-
tilation (PCV) hose.
(9) Remove oil fill tube. (10) Un-clip injector and ignition coil harness and
move away from cylinder head cover.
(11) Remove right rear breather tube and filter
assembly.
ENGINE - 3.7L
9 - 36
CYLINDER HEAD COVER(S) (Continued)
(12) Remove cylinder head cover retaining bolts. (13) Remove cylinder head cover.
INSTALLATION
CAUTION: Do not use harsh cleaners to clean the cylinder head covers. Severe damage to covers may occur.
NOTE: The gasket may be used again, provided no cuts, tears, or deformation has occurred.
DR
(3) For rocker arm removal on cylinder #1, Rotate the crankshaft until cylinder #1 is at BDC combus- tion stroke.
(4) For rocker arm removal on cylinders #3 and #5, Rotate the crankshaft until cylinder #1 is at TDC exhaust stroke.
(5) For rocker arm removal on cylinders #2 and #6, Rotate the crankshaft until cylinder #1 is at TDC ignition stroke.
(6) Using special tool 8516 Rocker Arm Remover, press downward on the valve spring, remove rocker arm (Fig. 28).
(1) Clean cylinder head cover and both sealing sur-
faces. Inspect and replace gasket as necessary.
(2) Tighten cylinder head cover bolts and double
ended studs to 12 N·m (105 in. lbs).
(3) Install right rear breather tube and filter
assembly.
(4) Connect injector, ignition coil electrical connec-
tors and harness retaining clips.
(5) Install the oil fill tube. (6) Install PCV hose. (7) Install heater hoses. (8) Install air conditioning compressor retaining
bolts.
(9) Install accessory drive belt(Refer to 7 - COOL- ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL- LATION).
(10) Fill Cooling system(Refer to 7 - COOLING -
STANDARD PROCEDURE).
(11) Install air cleaner assembly, resonator assem-
bly and air inlet hose.
(12) Connect battery negative cable.
ROCKER ARM DESCRIPTION
The rocker arms are steel stampings with an inte-
gral roller bearing. The rocker arms incorporate a 2.8
mm (0.11 inch) oil hole in the lash adjuster socket for
roller and camshaft lubrication.
REMOVAL
NOTE: Disconnect the battery negative cable to pre- vent accidental starter engagement.
(1) Remove the cylinder head cover (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - REMOVAL).
(2) For rocker arm removal on cylinder #4, Rotate the crankshaft until cylinder #1 is at BDC intake stroke.
Fig.28RockerArm-Removal
1 - CAMSHAFT
2 - SPECIAL TOOL 8516
VALVE GUIDE SEALS DESCRIPTION
The valve guide seals are made of rubber and incorporate an integral steel valve spring seat. The integral garter spring maintains consistent lubrica- tion control to the valve stems.
VALVE SPRINGS DESCRIPTION
The valve springs are made from high strength chrome silicon steel. There are different springs for intake and exhaust applications. The valve spring seat is integral with the valve stem seal, which is a positive type seal to control lubrication.
DR VALVE SPRINGS (Continued) REMOVAL
(1) Remove the cylinder head cover(Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - REMOVAL).
(2) Using Special Tool 8516 Valve Spring Compres- sor, remove the rocker arms and the hydraulic lash adjusters.
(3) Remove the spark plug for the cylinder the
valve spring and seal are to be removed from.
(4) Apply shop air to the cylinder to hold the
valves in place when the spring is removed.
NOTE: All six valve springs and seals are removed in the same manner; this procedure only covers one valve seal and valve spring.
(5) Using Special Tool 8387 Valve Spring Compres-
sor, compress the valve spring.
NOTE: It may be necessary to tap the top of the valve spring to loosen the spring retainers locks enough to be removed.
(6) Remove the two spring retainer lock halves.
NOTE: the valve spring is under tension use care when releasing the valve spring compressor.
(7) Remove the valve spring compressor.
NOTE: The valve springs are NOT common between intake and exhaust.
(8) Remove the spring retainer, and the spring. (9) Remove the valve stem seal.
NOTE: The valve stem seals are common between intake and exhaust.
INSTALLATION
NOTE: All six valve springs and seals are removed in the same manner; this procedure only covers one valve seal and valve spring.
(1) Apply shop air to the cylinder to hold the
valves in place while the spring is installed.
NOTE: The valve stem seals are common between intake and exhaust.
(2) Install the valve stem seal.
ENGINE - 3.7L
9 - 37
NOTE: The valve springs are NOT common between intake and exhaust.
(3) Install the spring retainer, and the spring. (4) Using Special Tool 8387 Valve Spring Compres-
sor, compress the valve spring.
(5) Install the two spring retainer lock halves.
NOTE: the valve spring is under tension use care when releasing the valve spring compressor.
(6) Remove the valve spring compressor. (7) Disconnect the shop air to the cylinder. (8) Install the spark plug for the cylinder the valve
spring and seal was installed on.
(9) Using Special Tool 8516 Valve Spring Compres- sor, install the rocker arms and the hydraulic lash adjusters.
(10) Install the cylinder head cover(Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - INSTALLATION).
ENGINE BLOCK DESCRIPTION
The cylinder block is made of cast iron. The block is a closed deck design with the left bank forward. To provide high rigidity and improved NVH an enhanced compacted graphite bedplate is bolted to the block. The block design allows coolant flow between the cylinders bores, and an internal coolant bypass to a single poppet inlet thermostat is included in the cast aluminum front cover.
STANDARD PROCEDURE—CYLINDER BORE HONING
Before honing, stuff plenty of clean shop towels under the bores and over the crankshaft to keep abrasive materials from entering the crankshaft area.
(1) Used carefully, the Cylinder Bore Sizing Hone C-823, equipped with 220 grit stones, is the best tool for this job. In addition to deglazing, it will reduce taper and out-of-round, as well as removing light scuffing, scoring and scratches. Usually, a few strokes will clean up a bore and maintain the required lim- its.
CAUTION: DO NOT use rigid type hones to remove cylinder wall glaze.
ENGINE - 3.7L
9 - 38
ENGINE BLOCK (Continued)
(2) Deglazing of the cylinder walls may be done if
the cylinder bore is straight and round. Use a cylin-
der surfacing hone, Honing Tool C-3501, equipped
with 280 grit stones (C-3501-3810). about 20-60
strokes, depending on the bore condition, will be suf-
ficient to provide a satisfactory surface. Using honing
oil C-3501-3880, or a light honing oil, available from
major oil distributors.
CAUTION: DO NOT use engine or transmission oil, mineral spirits, or kerosene.