OPERATION
The cylinder head closes the combustion chamber,
allowing the pistons to compress the fuel/air mixture
for ignition. The valves are actuated by the lobe pro-
files on the camshaft to open and close at specified
duration to either allow clean air in the combustion
chamber or the exhaust gases out; depending on the
stroke of the engine.
DIAGNOSIS AND TESTINGÐCYLINDER HEAD
GASKET
A cylinder head gasket leak can be located between
adjacent cylinders or between a cylinder and the
adjacent water jacket.
Possible indications of the cylinder head gasket
leaking between adjacent cylinders are:
²Loss of engine power
²Engine misfiring
²Poor fuel economy
Possible indications of the cylinder head gasket
leaking between a cylinder and an adjacent water
jacket are:
²Engine overheating
²Loss of coolant
²Excessive steam (white smoke) emitting from
exhaust
²Coolant 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 - CYLINDER HEAD
(1) Perform fuel system pressure release procedure
before attempting any repairs.(Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY - SPECIFICA-
TIONS)
(2) Disconnect battery negative cable.
(3) Drain cooling system. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
(4) Remove air filter housing and inlet tube.
(5) Remove upper intake manifold. (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
REMOVAL)
Fig. 13 Cylinder Head and Camshafts
1 - CAMSHAFT BEARING CAPS
2 - PLUG
3 - CAMSHAFT
4 - CYLINDER HEAD
5 - CAMSHAFT OIL SEAL
RSENGINE 2.4L9-23
CYLINDER HEAD (Continued)
ProCarManuals.com
(6) Remove heater tube support bracket from cyl-
inder head.
(7) Disconnect radiator upper and heater supply
hoses from intake manifold water outlet connections.
(8) Remove accessory drive belts. (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL)
(9) Raise vehicle and remove exhaust pipe from
manifold.
(10) Remove power steering pump reservoir and
line support bracket from lower intake manifold and
set aside. Do not disconnect lines.
(11) Remove ignition coil and wires from engine.
(12) Disconnect cam sensor and fuel injector wir-
ing connectors.
(13) Remove timing belt and camshaft sprockets.
(Refer to 9 - ENGINE/VALVE TIMING/TIMING
BELT/CHAIN AND SPROCKETS - REMOVAL)
(14) Remove timing belt idler pulley and rear tim-
ing belt cover. (Refer to 9 - ENGINE/VALVE TIM-
ING/TIMING BELT / CHAIN COVER(S) -
REMOVAL)
(15) Remove cylinder head cover. (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL)
(16) Remove camshafts (Refer to 9 - ENGINE/
CYLINDER HEAD/CAMSHAFT(S) - REMOVAL).
NOTE: Identify rocker arm position to ensure cor-
rect re-installation in original position, if reused.
(17) Remove rocker arms. (Refer to 9 - ENGINE/
CYLINDER HEAD/ROCKER ARMS - REMOVAL)
(18) Remove cylinder head bolts in REVERSE
sequence of tightening (Fig. 19).
(19) Remove cylinder head from engine block.
(20) Inspect and clean cylinder head. (Refer to 9 -
ENGINE/CYLINDER HEAD - INSPECTION) (Refer
to 9 - ENGINE/CYLINDER HEAD - CLEANING)
CLEANING
To ensure engine gasket sealing, proper surface
preparation must be performed, especially with the
use of aluminum engine components and multi-layer
steel cylinder head gaskets.
NOTE: Multi-Layer Steel (MLS) head gaskets require
a scratch free sealing surface.
Remove all gasket material from cylinder head and
block. (Refer to 9 - ENGINE - STANDARD PROCE-
DURE) Be careful not to gouge or scratch the alumi-
num head sealing surface.
Clean all engine oil passages.
INSPECTION
(1) Cylinder head must be flat within 0.1 mm
(0.004 in.) (Fig. 14).
(2) Inspect camshaft bearing journals for scoring.
(3) Remove carbon and varnish deposits from
inside of valve guides with a reliable guide cleaner.
(4) Using a small hole gauge and a micrometer,
measure valve guides in 3 places top, middle and bot-
tom (Fig. 15). (Refer to 9 - ENGINE - SPECIFICA-
TIONS) Replace guides if they are not within
specification.
(5) Check valve guide height (Fig. 16).
INSTALLATION - CYLINDER HEAD
NOTE: The Cylinder head bolts should be examined
BEFORE reuse. If the threads are necked down, the
bolts must be replaced (Fig. 17).
Fig. 14 Checking Cylinder Head Flatness
1 - FEELER GAUGE
2 - STRAIGHT EDGE
Fig. 15 Checking Wear on Valve GuideÐTypical
1-TOP
2 - MIDDLE
3 - BOTTOM
4 - CUT AWAY VIEW OF VALVE GUIDE MEASUREMENT
LOCATIONS
9 - 24 ENGINE 2.4LRS
CYLINDER HEAD (Continued)
ProCarManuals.com
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.
(1) Before installing the bolts, the threads should
be coated with engine oil.
(2) Position cylinder head gasket on engine block
(Fig. 18).
(3) Install cylinder head on engine block.
(4) Tighten the cylinder head bolts in the sequence
shown in (Fig. 19). Using the 4 step torque turn
method, tighten according to the following values:
²First All to 34 N´m (25 ft. lbs.)
²Second All to 68 N´m (50 ft. lbs.)
²Third All to 68 N´m (50 ft. lbs.)
CAUTION: Do not use a torque wrench for the fol-
lowing step.
²Fourth Turn an additional 1/4 Turn,(5) Install rocker arms. (Refer to 9 - ENGINE/
CYLINDER HEAD/ROCKER ARMS - INSTALLA-
TION)
(6) Install camshafts. (Refer to 9 - ENGINE/CYL-
INDER HEAD/CAMSHAFT(S) - INSTALLATION).
(7) Install cylinder head cover. (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION)
(8) Install timing belt rear cover and timing belt
idler pulley. (Refer to 9 - ENGINE/VALVE TIMING/
TIMING BELT / CHAIN COVER(S) - INSTALLA-
TION)
(9) Install timing belt and camshaft sprockets.
(Refer to 9 - ENGINE/VALVE TIMING/TIMING
BELT/CHAIN AND SPROCKETS - INSTALLATION)
(10) Connect cam sensor and fuel injectors wiring
connectors.
(11) Install ignition coil and wires. Connect igni-
tion coil wiring connector.
(12) Install power steering pump reservoir and
line support bracket to cylinder head.
Fig. 16 Valve Guide Height
1 - VALVE GUIDE
2 - 13.25 - 13.75 MM (0.521 - 0.541 IN.)
3 - SPRING SEAT
Fig. 17 Checking Bolts for
1 - STRETCHED BOLT
2 - THREADS ARE NOT STRAIGHT ON LINE
3 - THREADS ARE STRAIGHT ON LINE
4 - UNSTRETCHED BOLT
Fig. 18 Cylinder Head Gasket Positioning
1 - PART NUMBER FACES UP
2 - NO. 1 CYLINDER
Fig. 19 Cylinder Head Tightening Sequence
RSENGINE 2.4L9-25
CYLINDER HEAD (Continued)
ProCarManuals.com
NOTE: Bearing end caps must be installed before
seals can be installed.
(5) Install camshaft oil seals. (Refer to 9 -
ENGINE/CYLINDER HEAD/CAMSHAFT OIL
SEAL(S) - INSTALLATION)
(6) Install camshaft target magnet and camshaft
position sensor.
(7) Install cylinder head cover. (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION)
(8) Install timing belt rear cover and camshaft
sprocket. (Refer to 9 - ENGINE/VALVE TIMING/
TIMING BELT / CHAIN COVER(S) - INSTALLA-
TION)
(9) Install timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - INSTALLATION)
CYLINDER HEAD COVER
REMOVAL
(1) Remove upper intake manifold. (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
REMOVAL)
(2) Remove upper manifold support bracket.
(3) Remove ignition coil and spark plug wires.
(4) Disconnect PCV and make-up air hoses from
cylinder head cover.
(5) Remove cylinder head cover bolts.
(6) Remove cylinder head cover from cylinder
head.
CLEANING
Clean cylinder head and cover mating surfaces
using a suitable solvent.
INSPECTION
Inspect cover rails for flatness.
INSTALLATION
NOTE: Replace spark plug well seals and bolt
assemblies when installing a new cylinder head
cover gasket.
(1) Install new cylinder head cover gaskets and
spark plug well seals (Fig. 30).
(2) Replace cylinder head cover bolt assemblies
(Fig. 31).
CAUTION: Do not allow oil or solvents to contact
the timing belt as they can deteriorate the rubber
and cause tooth skipping.
Fig. 29 Camshaft Bearing Cap Sealing
1 - 1.5 mm (.060 in.) DIAMETER BEAD OF MOPAR GASKET
MAKER
Fig. 30 Spark Plug Well Seals
Fig. 31 Cylinder Head Cover Bolt Assembly
RSENGINE 2.4L9-29
CAMSHAFT(S) (Continued)
ProCarManuals.com
(3) Apply MopartEngine RTV GEN II at the
camshaft cap corners and at the top edges of the 1/2
round seal (Fig. 32).
(4) Install cylinder head cover assembly to cylin-
der head. Install all bolts, ensuring the two (2) bolts
containing the sealing washer are located in the cen-
ter locations of cover. Tighten bolts in sequence
shown in (Fig. 33). Using a 3 step torque method as
follows:
(a) Tighten all bolts to 4.5 N´m (40 in. lbs.).
(b) Tighten all bolts to 9.0 N´m (80 in. lbs.).
(c) Tighten all bolts to 12 N´m (105 in. lbs.).
(5) Install ignition coil and spark plug wires.
Tighten fasteners to 12 N´m (105 in. lbs.).
(6) If the PCV valve was removed, apply Mopart
Thread Sealant with Teflon to threads and install
valve to cylinder head cover. Tighten PCV valve to 8
N´m (70 in. lbs.).
(7) Connect PCV and make-up air hoses to cylin-
der head cover.(8) Install upper intake manifold. (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
INSTALLATION)
INTAKE/EXHAUST VALVES &
SEATS
DESCRIPTION
The valves are made of heat resistant steel. They
have chrome plated stems to prevent scuffing. Viton
rubber valve stem seals are integral with the spring
seats. The valves have three-bead lock keepers to
retain springs and to promote valve rotation.
CLEANING
(1) Clean all valves thoroughly and discard
burned, warped and cracked valves.
VALVE SPRINGS
REMOVAL - CYLINDER HEAD ON
(1) Remove camshafts.
(2) Rotate crankshaft until piston is at TDC on
compression.
(3) With air hose attached to adapter tool installed
in spark plug hole, apply 90-120 psi air pressure.
(4) Using Special Tool MD-998772-A with adapter
6779 (Fig. 34), compress valve springs and remove
valve locks.
(5) Remove valve spring(s).
(6) Remove valve stem seal(s) by a using valve
stem seal tool (Fig. 36).
REMOVAL - CYLINDER HEAD OFF
(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-
Fig. 32 Sealer Locations
1 ± SEALER LOCATION
Fig. 33 Cylinder Head Cover Tightening Sequence
(Typical Cover Shown)
9 - 30 ENGINE 2.4LRS
CYLINDER HEAD COVER (Continued)
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DIAGNOSIS AND TESTING - ENGINE
Engine diagnosis is helpful in determining the
causes of malfunctions not detected and remedied by
routine maintenance.
These malfunctions may be classified as either
mechanical (e.g., a strange noise), or performance
(e.g., engine idles rough and stalls).
Refer to the Engine Mechanical and the Engine
Performance diagnostic charts, for possible causes
and corrections of malfunctions (Refer to 9 - ENGINE
- DIAGNOSIS AND TESTING - MECHANICAL)
(Refer to 9 - ENGINE - DIAGNOSIS AND TESTING
- PERFORMANCE).
For fuel system diagnosis, (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY - DIAGNOSIS AND
TESTING).
Additional tests and diagnostic procedures may be
necessary for specific engine malfunctions that can-
not be isolated with the Service Diagnosis charts.
Information concerning additional tests and diagno-
sis is provided within the following:
²Cylinder Compression Pressure Test
²Cylinder Combustion Pressure Leakage Test
²Engine Cylinder Head Gasket Failure Diagnosis
²Intake Manifold Leakage Diagnosis
²Lash Adjuster (Tappet) Noise Diagnosis
²Engine Oil Leak Inspection
DIAGNOSIS AND TESTING - ENGINE PERFORMANCE
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE WILL
NOT START1. Weak battery. 1. Test battery. Charge or replace as
necessary. (Refer to 8 - ELECTRICAL/
BATTERY SYSTEM - DIAGNOSIS AND
TESTING)
2. Corroded or loose battery connections. 2. Clean and tighten battery connections.
Apply a coat of light mineral grease to
terminals.
3. Faulty starter. 3. Test starting system. (Refer to 8 -
ELECTRICAL/STARTING - DIAGNOSIS
AND TESTING)
4. Faulty coil(s) or control unit. 4. Test and replace as needed. (Refer to
Appropriate Diagnostic Information)
5. Incorrect spark plug gap. 5. Set gap. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL - SPECIFICATIONS)
6. Contamination in fuel system. 6. Clean system and replace fuel filter.
7. Faulty fuel pump. 7. Test fuel pump and replace as needed.
(Refer to Appropriate Diagnostic Information)
8. Incorrect engine timing. 8. Check for a skipped timing belt/chain.
Fig. 2 Engine Identification
9 - 74 ENGINE 3.3/3.8LRS
ENGINE 3.3/3.8L (Continued)
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CONDITION POSSIBLE CAUSE CORRECTION
ENGINE STALLS
OR IDLES
ROUGH1. Idle speed too low. 1. Test minimum air flow. (Refer to
Appropriate Diagnostic Information)
2. Incorrect fuel mixture. 2. (Refer to Appropriate Diagnostic
Information)
3. Intake manifold leakage. 3. Inspect intake manifold, manifold gasket,
and vacuum hoses.
4. Faulty ignition coil(s). 4. Test and replace as necessary. (Refer to
Appropriate Diagnostic Information)
ENGINE LOSS OF
POWER1. Dirty or incorrectly gapped plugs. 1. Clean plugs and set gap.
2. Contamination in fuel system. 2. Clean system and replace fuel filter.
3. Faulty fuel pump. 3. Test and replace as necessary. (Refer to
Appropriate Diagnostic Information)
4. Incorrect valve timing. 4. Correct valve timing.
5. Leaking cylinder head gasket. 5. Replace cylinder head gasket.
6. Low compression. 6. Test compression of each cylinder.
7. Burned, warped, or pitted valves. 7. Replace valves.
8. Plugged or restricted exhaust system. 8. Perform exhaust restriction test. (Refer to
11 - EXHAUST SYSTEM - DIAGNOSIS AND
TESTING) Install new parts, as necessary.
9. Faulty ignition coil(s). 9. Test and replace as necessary. (Refer to
Appropriate Diagnostic Information)
ENGINE MISSES
ON
ACCELERATION1. Dirty or incorrectly gapped spark plugs. 1. Clean spark plugs and set gap.
2. Contamination in Fuel System. 2. Clean fuel system and replace fuel filter.
3. Burned, warped, or pitted valves. 3. Replace valves.
4. Faulty ignition coil(s). 4. Test and replace as necessary. (Refer to
Appropriate Diagnostic Information)
ENGINE MISSES
AT HIGH SPEED1. Dirty or incorrect spark plug gap. 1. Clean spark plugs and set gap.
2. Faulty ignition coil(s). 2. Test and replace as necessary. (Refer to
Appropriate Diagnostic Information)
3. Dirty fuel injector(s). Test and replace as necessary. (Refer to
Appropriate Diagnostic Information)
4. Contamination in fuel system. 4. Clean system and replace fuel filter.
RSENGINE 3.3/3.8L9-75
ENGINE 3.3/3.8L (Continued)
ProCarManuals.com
²Gradually apply air pressure from 1 psi to 2.5
psi maximum while applying soapy water at the sus-
pected source. Adjust the regulator to the suitable
test pressure that provides the best bubbles which
will pinpoint the leak source. If the oil leak is
detected and identified, repair per service manual
procedures.
²If the leakage occurs at the crankshaft rear oil
seal area, refer to the section, Inspection for Rear
Seal Area Leak.
(6) If no leaks are detected, turn off the air supply.
Remove the air hose, all plugs, and caps. Install the
PCV valve and fresh air hose (make-up air). Proceed
to next step.
(7) Clean the oil off the suspect oil leak area using
a suitable solvent. Drive the vehicle at various
speeds approximately 24 km (15 miles). Inspect the
engine for signs of an oil leak by using a black light.
NOTE: If oil leakage is observed at the dipstick tube
to block location; remove the tube, clean and reseal
using MoparTStud & Bearing Mount (press fit tube
applications only), and for O-ring style tubes,
remove tube and replace the O-ring seal.
INSPECTION FOR REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the
source of an oil leak in the rear seal area of the
engine, a more involved inspection is necessary. The
following steps should be followed to help pinpoint
the source of the leak.
If the leakage occurs at the crankshaft rear oil seal
area:
(1) Disconnect the battery.
(2) Raise the vehicle.
(3) Remove torque converter or clutch housing
cover and inspect rear of block for evidence of oil.
Use a black light to check for the oil leak. If a leak is
present in this area, remove transmission for further
inspection.
(a) Circular spray pattern generally indicates
seal leakage or crankshaft damage.
(b) Where leakage tends to run straight down,
possible causes are a porous block, oil gallery cup
plug, bedplate to cylinder block mating surfaces
and seal bore. See proper repair procedures for
these items.
(4) If no leaks are detected, pressurize the crank-
case as previously described.
CAUTION: Do not exceed 20.6 kPa (3 psi).
(5) If the leak is not detected, very slowly turn the
crankshaft and watch for leakage. If a leak is
detected between the crankshaft and seal while
slowly turning the crankshaft, it is possible thecrankshaft seal surface is damaged. The seal area on
the crankshaft could have minor nicks or scratches
that can be polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft
polishing is necessary to remove minor nicks and
scratches. The crankshaft seal flange is especially
machined to complement the function of the rear oil
seal.
(6) For bubbles that remain steady with shaft
rotation, no further inspection can be done until dis-
assembled.
(7) After the oil leak root cause and appropriate
corrective action have been identified, replace compo-
nent(s) as necessary.
DIAGNOSIS AND TESTING - CYLINDER
COMPRESSION PRESSURE
The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunc-
tions.
Ensure the battery is completely charged and the
engine starter motor is in good operating condition.
Otherwise the indicated compression pressures may
not be valid for diagnosis purposes.
(1) Check engine oil level and add oil if necessary.
(2) Drive the vehicle until engine reaches normal
operating temperature. Select a route free from traf-
fic and other forms of congestion, observe all traffic
laws, and accelerate through the gears several times
briskly.
(3) Remove all spark plugs from engine. As spark
plugs are being removed, check electrodes for abnor-
mal firing indicators fouled, hot, oily, etc. Record cyl-
inder number of spark plug for future reference.
(4) Disconnect the ignition coil electrical connector.
(5) Be sure throttle blade is fully open during the
compression check.
(6) Insert compression gage adaptor Special Tool
8116 or the equivalent, into the #1 spark plug hole in
cylinder head. Connect the 0±500 psi (Blue) pressure
transducer with cable adaptors to the DRBIIIt.
(7) Crank engine until maximum pressure is
reached on gage. Record this pressure as #1 cylinder
pressure.
(8) Repeat the previous step for all remaining cyl-
inders.
(9) Compression should not be less than 689 kPa
(100 psi) and not vary more than 25 percent from cyl-
inder to cylinder.
(10) If one or more cylinders have abnormally low
compression pressures, repeat the compression test.
(11) If the same cylinder or cylinders repeat an
abnormally low reading on the second compression
test, it could indicate the existence of a problem in
9 - 78 ENGINE 3.3/3.8LRS
ENGINE 3.3/3.8L (Continued)
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