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)
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(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)
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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)
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OPERATION
The camshaft is driven by the crankshaft via drive
sprockets and belt. The camshaft has precisely
machined lobes to provide accurate valve timing and
duration.
STANDARD PROCEDURES - CAMSHAFT
END-PLAY
(1) Oil camshaft journals and install camshaft
WITHOUTcam follower assemblies. Install rear cam
caps and tighten screws to specified torque.
(2) Using a suitable tool, move camshaft as far
rearward as it will go.
(3) Zero dial indicator (Fig. 24).
(4) Move camshaft as far forward as it will go.
(5) Record reading on dial indicator. For end play
specification, (Refer to 9 - ENGINE - SPECIFICA-
TIONS).
(6) If end play is excessive, check cylinder head
and camshaft for wear; replace as necessary.
REMOVAL
(1) Remove cylinder head cover. (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL)
(2) Remove camshaft position sensor and camshaft
target magnet. (Refer to 8 - ELECTRICAL/IGNI-
TION CONTROL/CAMSHAFT POSITION SENSOR -
REMOVAL)
(3) Remove timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - REMOVAL)
(4) Remove camshaft sprockets and timing belt
rear cover. (Refer to 9 - ENGINE/VALVE TIMING/
TIMING BELT / CHAIN COVER(S) - REMOVAL)
(5) Bearing caps are identified for location.
Remove the outside bearing caps first (Fig. 25).
(6) Loosen the camshaft bearing cap attaching
fasteners in sequence shown (Fig. 26) one camshaft
at a time.
CAUTION: Camshafts are not interchangeable. The
intake cam number 6 thrust bearing face spacing is
wider.
Fig. 22 Camshaft Seal - Installation
1 - SPECIAL TOOL MD 998306
Fig. 23 Camshafts
1 - CAMSHAFT BEARING CAPS
2 - PLUG
3 - CAMSHAFT
4 - CYLINDER HEAD
5 - CAMSHAFT OIL SEAL
Fig. 24 Camshaft End Play - Typical
RSENGINE 2.4L9-27
CAMSHAFT(S) (Continued)
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(7) Identify the camshafts before removing from
the head. The camshafts are not interchangeable.
(8) Remove camshafts from cylinder head.
NOTE: If removing rocker arms, identify for reinstal-
lation in the original position.
CLEANING
Clean camshaft with a suitable solvent.
INSPECTION
(1) Inspect camshaft bearing journals for damage
and binding (Fig. 27). If journals are binding, check
the cylinder head for damage. Also check cylinder
head oil holes for clogging.
(2) Check the cam lobe and bearing surfaces for
abnormal wear and damage. Replace camshaft if
defective.
NOTE: If camshaft is replaced due to lobe wear or
damage, always replace the rocker arms.(3) Measure the lobe actual wear (unworn area -
wear zone = actual wear) (Fig. 27) and replace cam-
shaft if out of limit. Standard value is 0.0254 mm
(0.001 in.), wearlimitis 0.254 mm (0.010 in.).
INSTALLATION
CAUTION: Ensure that NONE of the pistons are at
top dead center when installing the camshafts.
(1) Lubricate all camshaft bearing journals, rocker
arms and camshaft lobes.
(2) Install all rocker arms in original positions, if
reused.
(3) Position camshafts on cylinder head bearing
journals. Install right and left camshaft bearing caps
No.2±5andright No. 6. Tighten M6 fasteners to 12
N´m (105 in. lbs.) in sequence shown in (Fig. 28).
(4) Apply MopartGasket Maker to No. 1 and No.
6 bearing caps (Fig. 29). Install bearing caps and
tighten M8 fasteners to 28 N´m (250 in. lbs.).
Fig. 25 Camshaft Bearing Cap Identification
Fig. 26 Camshaft Bearing Cap - Removal
1 - REMOVE OUTSIDE BEARING CAPS FIRST
Fig. 27 Checking Camshaft(s) for Wear
1 - UNWORN AREA
2 - ACTUAL WEAR
3 - BEARING JOURNAL
4 - LOBE
5 - WEAR ZONE
Fig. 28 Camshaft Bearing Cap Tightening Sequence
9 - 28 ENGINE 2.4LRS
CAMSHAFT(S) (Continued)
ProCarManuals.com
CAUTION: When depressing the valve spring retain-
ers 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. 37). 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 0.762 mm (0.030
in.) spacer under the valve spring seat to bring
spring height back within specification.
HYDRAULIC LIFTERS
DIAGNOSIS AND TESTING - LASH ADJUSTER
(TAPPET) NOISE
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) During this time, 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 (integral to the head gasket)
in the vertical oil passage to the cylinder head is
plugged with debris.
(6) Air ingested into oil due to broken or cracked
oil pump pick up.
(7) Worn valve guides.
(8) Rocker arm ears contacting valve spring
retainer.(9) Rocker arm loose, adjuster stuck or at maxi-
mum extension and still leaves lash in the system.
(10) Faulty lash adjuster.
²Check lash adjusters for sponginess while
installed in cylinder head. Depress part of rocker
arm over adjuster. Normal adjusters should feel very
firm. Spongy adjusters can be bottomed out easily.
²Remove suspected lash adjusters, and replace as
necessary.
REMOVAL
NOTE: This procedure is for in-vehicle service with
camshafts installed.
(1) Remove cylinder head cover. (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL)
(2) Remove rocker arm. (Refer to 9 - ENGINE/
CYLINDER HEAD/ROCKER ARMS - REMOVAL)
(3) Remove hydraulic lifter (Fig. 38).
(4) Repeat removal procedure for each hydraulic
lifter.
(5) If reusing, mark each hydraulic lifter for reas-
sembly in original position. Lifters are serviced as an
assembly.
INSTALLATION
(1) Install hydraulic lifter (Fig. 38). Ensure the
lifters are at least partially full of engine oil. This is
indicated by little or no plunger travel when the
lifter is depressed.
(2) Install rocker arm. (Refer to 9 - ENGINE/CYL-
INDER HEAD/ROCKER ARMS - INSTALLATION)
(3) Repeat installation procedure for each hydrau-
lic lifter.
(4) Install cylinder head cover. (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION)
Fig. 37 Checking Spring Installed Height and Valve
Tip Height Dimensions
1 - GARTER SPRING
2 - VALVE SPRING SEAT
3 - CYLINDER HEAD SURFACE
Fig. 38 Hydraulic Lifter
9 - 32 ENGINE 2.4LRS
VALVE SPRINGS (Continued)
ProCarManuals.com
should be measured halfway down the cylinder bore
and transverse to the engine crankshaft center line
shown in (Fig. 42). Refer to for Engine Specifications
(Refer to 9 - ENGINE - SPECIFICATIONS). Correct
piston to bore clearance must be established in order
to assure quiet and economical operation.
NOTE: Pistons and cylinder bores should be mea-
sured at normal room temperature, 21ÉC (70ÉF).
STANDARD PROCEDURES - CYLINDER BORE
HONING
(1) Used carefully, the cylinder bore resizing hone,
recommended tool C-823 or equivalent, equipped
with 220 grit stones, is the best tool for this honing
procedure. In addition to deglazing, it will reducetaper and out-of-round as well as removing light
scuffing, scoring or scratches. Usually a few strokes
will clean up a bore and maintain the required lim-
its.
(2) Deglazing of the cylinder walls may be done
using a cylinder surfacing hone, recommended tool
C-3501 or equivalent, equipped with 280 grit stones,
if the cylinder bore is straight and round. 20±60
strokes depending on the bore condition, will be suf-
ficient to provide a satisfactory surface. Use a light
honing oil.Do not use engine or transmission oil,
mineral spirits or kerosene.Inspect cylinder walls
after each 20 strokes.
(3) Honing should be done by moving the hone up
and down fast enough to get a cross-hatch pattern.
When hone marksintersectat 40-60 degrees, the
cross hatch angle is most satisfactory for proper seat-
ing of rings (Fig. 44).
Fig. 41 Cylinder Block and Bedplate
1 - CYLINDER BLOCK
2 - BEDPLATE
Fig. 42 Checking Cylinder Bore
Fig. 43 Piston Measurement
Fig. 44 Cylinder Bore Cross-Hatch Pattern
1 - CROSS-HATCH PATTERN
2 - 40ɱ60É
9 - 34 ENGINE 2.4LRS
ENGINE BLOCK (Continued)
ProCarManuals.com
(4) A controlled hone motor speed between
200±300 RPM is necessary to obtain the proper cross-
hatch angle. The number of up and down strokes per
minute can be regulated to get the desired 40±60
degree angle. Faster up and down strokes increase
the cross-hatch angle.
(5) After honing, it is necessary that the block be
cleaned again to remove all traces of abrasive.
CAUTION: Ensure all abrasives are removed from
engine parts after honing. It is recommended that a
solution of soap and hot water be used with a
brush and the parts then thoroughly dried. The bore
can be considered clean when it can be wiped
clean with a white cloth and cloth remains clean.
Oil the bores after cleaning to prevent rusting.
CLEANING
Clean cylinder block thoroughly using a suitable
cleaning solvent.
INSPECTION
ENGINE BLOCK
(1) Clean cylinder block thoroughly and check all
core hole plugs for evidence of leaking.
(2) If new core plugs are to be installed, refer to
Engine Core Plugs for procedures (Refer to 9 -
ENGINE - STANDARD PROCEDURE).
(3) Examine block and cylinder bores for cracks or
fractures.
(4) Check block deck surfaces for flatness. Deck
surface must be within service limit of 0.1 mm (0.004
in.).
CYLINDER BORE
NOTE: The cylinder bores should be measured at
normal room temperature, 21ÉC (70ÉF).
The cylinder walls should be checked for out-of-
round and taper with Tool C119 or equivalent (Fig.
45). (Refer to 9 - ENGINE - SPECIFICATIONS) If
the cylinder walls are badly scuffed or scored, the
cylinder block should be replaced, and new pistons
and rings fitted.
Measure the cylinder bore at three levels in direc-
tions A and B (Fig. 45). Top measurement should be
10 mm (3/8 in.) down and bottom measurement
should be 10 mm (3/8 in.) up from bottom of bore.
Refer to Engine Specifications (Refer to 9 - ENGINE
- SPECIFICATIONS).
CONNECTING ROD BEARINGS
CONNECTING RODÐFITTING
(1) For measuring connecting rod bearing clear-
ance procedure and use of Plastigage(Refer to 9 -
ENGINE - STANDARD PROCEDURE). For bearing
clearance refer to Engine Specifications. (Refer to 9 -
ENGINE - SPECIFICATIONS)
NOTE: The rod bearing bolts should not be reused.
(2) Before installing theNEWbolts the threads
should be oiled with clean engine oil.
(3) Install each bolt finger tight than alternately
torque each bolt to assemble the cap properly.
(4) Tighten the bolts to 27 N´m PLUS 1/4 turn (20
ft. lbs. PLUS 1/4 turn)Do not use a torque
wrench for last step.
(5) Using a feeler gauge, check connecting rod side
clearance (Fig. 46). Refer to clearance specifications
(Refer to 9 - ENGINE - SPECIFICATIONS).
Fig. 45 Checking Cylinder Bore Size
RSENGINE 2.4L9-35
ENGINE BLOCK (Continued)
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