DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - MECHANICAL
CONDITION POSSIBLE CAUSES CORRECTION
NOISY VALVES 1. High or low oil level in
crankcase.1. Check and correct engine oil
level.
2. Thin or diluted oil. 2. Change oil to correct viscosity.
3. Thick oil 3. (a) Change engine oil and filter.
(b) Run engine to operating
temperature.
(c) Change engine oil and filter
again.
4. Low oil pressure. 4. Check and correct engine oil
pressure problem.
5. Dirt in hydraulic lifters/lash
adjusters.5. Replace hydraulic lifters/lash
adjusters.
6. Worn rocker arms. 6. Inspect oil supply to rocker arms.
7. Worn hydraulic lifters/lash
adjusters.7. Replace hydraulic lifters/lash
adjusters.
8. Worn valve guides. 8. Replace cylinder head assembly.
9. Excessive runout of valve seats
on valve faces.9. Grind valve seats and valves.
CONNECTING ROD NOISE 1. Insufficient oil supply. 1. Check engine oil level.
2. Low oil pressure. 2. Check engine oil level. Inspect oil
pump relief valve and spring.
3. Thin or diluted oil. 3. Change oil to correct viscosity.
4. Thick oil 4. (a) Change engine oil and filter.
(b) Run engine to operating
temperature.
(c) Change engine oil and filter
again.
5. Excessive bearing clearance. 5. Measure bearings for correct
clearance. Repair as necessary.
6. Connecting rod journal
out-of-round.6. Replace crankshaft or grind
surface.
7. Misaligned connecting rods. 7. Replace bent connecting rods.
9 - 6 ENGINE 2.4LRS
ENGINE 2.4L (Continued)
ProCarManuals.com
CONDITION POSSIBLE CAUSES CORRECTION
MAIN BEARING NOISE 1. Insufficient oil supply. 1. Check engine oil level.
2. Low oil pressure. 2. Check engine oil level. Inspect oil
pump relief valve and spring.
3. Thin or diluted oil. 3. Change oil to correct viscosity.
4. Thick oil 4. (a) Change engine oil and filter.
(b) Run engine to operating
temperature.
(c) Change engine oil and filter
again.
5. Excessive bearing clearance. 5. Measure bearings for correct
clearance. Repair as necessary.
6. Excessive end play. 6. Check thrust bearing for wear on
flanges.
7. Crankshaft journal out-of-round
or worn.7. Replace crankshaft or grind
journals.
8. Loose flywheel or torque
converter.8. Tighten to correct torque.
OIL PRESSURE DROP 1. Low oil level. 1. Check engine oil level.
2. Faulty oil pressure sensor/switch. 2. Replace oil pressure sensor/
switch.
3. Low oil pressure. 3. Check oil pressure sensor/switch
and main bearing oil clearance.
4. Clogged oil filter. 4. Install new oil filter.
5. Worn parts in oil pump. 5. Replace worn parts or pump.
6. Thin or diluted oil. 6. Change oil to correct viscosity.
7. Oil pump relief valve stuck. 7. Remove valve and inspect, clean,
or replace.
8. Oil pump suction tube loose. 8. Remove oil pan and install new
tube or clean, if necessary.
9. Oil pump cover warped or
cracked.9. Install new oil pump.
10. Excessive bearing clearance. 10. Measure bearings for correct
clearance.
OIL LEAKS 1. Misaligned or deteriorated
gaskets.1. Replace gasket(s).
2. Loose fastener, broken or porous
metal part.2. Tighten, repair or replace the
part.
3. Misaligned or deteriorated cup or
threaded plug.3. Replace as necessary.
RSENGINE 2.4L9-7
ENGINE 2.4L (Continued)
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CONDITION POSSIBLE CAUSES CORRECTION
OIL CONSUMPTION OR SPARK
PLUGS FOULED1. PCV system malfunction. 1. Check system and repair as
necessary. (Refer to 25 -
EMISSIONS CONTROL/
EVAPORATIVE EMISSIONS/PCV
VALVE - DIAGNOSIS AND
TESTING)
2. Worn, scuffed or broken rings. 2. Hone cylinder bores. Install new
rings.
3. Carbon in oil ring slots. 3. Install new rings.
4. Rings fitted too tightly in grooves. 4. Remove rings and check
grooves. If groove is not proper
width, replace piston.
5. Worn valve guide(s). 5. Replace cylinder head assembly.
6. Valve stem seal(s) worn or
damaged.6. Replace seal(s).
DIAGNOSIS AND TESTING - ENGINE OIL LEAK
INSPECTION
Begin with a thorough visual inspection of the
engine, particularly at the area of the suspected leak.
If an oil leak source is not readily identifiable, the
following steps should be followed:
(1) Do not clean or degrease the engine at this
time because some solvents may cause rubber to
swell, temporarily stopping the leak.
(2) Add an oil soluble dye (use as recommended by
manufacturer). Start the engine and let idle for
approximately 15 minutes. Check the oil dipstick to
make sure the dye is thoroughly mixed as indicated
with a bright yellow color under a black light.
(3) Using a black light, inspect the entire engine
for fluorescent dye, particularly at the suspected area
of oil leak. If the oil leak is found and identified,
repair as necessary.
(4) If dye is not observed, drive the vehicle at var-
ious speeds for approximately 24 km (15 miles), and
repeat inspection.
(5)If the oil leak source is not positively
identified at this time, proceed with the air leak
detection test method as follows:
²Disconnect the fresh air hose (make-up air) at
the cylinder head cover and plug or cap the nipple on
the cover.
²Remove the PCV valve hose from the cylinder
head cover. Cap or plug the PCV valve nipple on the
cover.
²Attach an air hose with pressure gauge and reg-
ulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to
more than 20.6 kpa (3 PSI) of test pressure.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.
9 - 8 ENGINE 2.4LRS
ENGINE 2.4L (Continued)
ProCarManuals.com
(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 the
crankshaft 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 TEST
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) Remove the Auto Shutdown (ASD) relay from
the PDC.
(5) Be sure throttle blade is fully open during the
compression check.
(6) Insert compression gauge adaptor Special Tool
8116 or the equivalent, into the #1 spark plug hole in
cylinder head. Connect the 0±500 psi (Blue) pressure
transducer (Special Tool CH7059) with cable adap-
tors to the DRBIIIt. For Special Tool identification,
(Refer to 9 - ENGINE - SPECIAL TOOLS).
(7) Crank engine until maximum pressure is
reached on gauge. Record this pressure as #1 cylin-
der 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
the cylinder in question.The recommended com-
pression pressures are to be used only as a
guide to diagnosing engine problems. An engine
should not be disassembled to determine the
cause of low compression unless some malfunc-
tion is present.
DIAGNOSIS AND TESTING - CYLINDER
COMBUSTION PRESSURE LEAKAGE TEST
The combustion pressure leakage test provides an
accurate means for determining engine condition.
Combustion pressure leakage testing will detect:
²Exhaust and intake valve leaks (improper seat-
ing).
²Leaks between adjacent cylinders or into water
jacket.
²Any causes for combustion/compression pressure
loss.
WARNING: DO NOT REMOVE THE PRESSURE CAP
WITH THE SYSTEM HOT AND UNDER PRESSURE
BECAUSE SERIOUS BURNS FROM COOLANT CAN
OCCUR.
Check the coolant level and fill as required. DO
NOT install the pressure cap.
Start and operate the engine until it attains nor-
mal operating temperature, then turn the engine
OFF.
Clean spark plug recesses with compressed air.
Remove the spark plugs.
Remove the oil filler cap.
Remove the air cleaner.
RSENGINE 2.4L9-9
ENGINE 2.4L (Continued)
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REMOVAL - ENGINE ASSEMBLY
(1) Perform fuel pressure release procedure (Refer
to 14 - FUEL SYSTEM/FUEL DELIVERY - STAN-
DARD PROCEDURE)
(2) Disconnect battery negative cable.
(3) Remove air cleaner housing and inlet tube.
(4) Disconnect the fuel line from fuel rail. (Refer to
14 - FUEL SYSTEM/FUEL DELIVERY/FUEL LINES
- STANDARD PROCEDURE)
(5) Disconnect all vacuum hoses.
(6) Drain cooling system. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
(7) Remove radiator fans. (Refer to 7 - COOLING/
ENGINE/RADIATOR FAN - REMOVAL)
(8) Remove radiator upper and lower hoses.
NOTE: When the transaxle cooler lines are removed
from the rolled-groove type fittings at the transaxle,
damage to the inner wall of the hose will occur. To
prevent prevent potential leakage, the cooler hoses
must be cut off flush at the transaxle fitting, and a
service cooler hose splice kit must be installed
upon reassembly.(9) Using a blade or suitable hose cutter, cut trans-
axle oil cooler lines off flush with fittings. Plug cooler
lines and fittings to prevent debris from entering
transaxle or cooler circuit. A service splice kit will be
installed upon reassembly.
(10) Disconnect transmission shift linkage and
electrical connectors.
(11) Disconnect throttle body linkage.
(12) Disconnect engine wiring harness.
(13) Disconnect heater hoses from heater (Fig. 5).
(14) Discharge air conditioning system. (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING
- STANDARD PROCEDURE)
(15) Hoist vehicle and remove front wheels and
tires.
(16) Remove accessory drive belt splash shield.
(17) Remove accessory drive belts. (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL)
Fig. 5 HEATER HOSES - 2.4L
1 - HEATER HOSES TO HEATER 3 - HEATER HOSE TO ENGINE - SUPPLY AND RETURN
2 - BOLT - HEATER TUBE SUPPORT
RSENGINE 2.4L9-13
ENGINE 2.4L (Continued)
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(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 & SEALS
REMOVAL
REMOVAL - CYLINDER HEAD ON
(1) Remove cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(2) Remove camshafts (Refer to 9 - ENGINE/CYL-
INDER HEAD/CAMSHAFT(S) - REMOVAL).
(3) Rotate crankshaft until piston is at TDC on
compression.
(4) With air hose attached to adapter tool installed
in spark plug hole, apply 90-120 psi air pressure.(5) Using Special Tool MD-998772-A with adapter
6779 (Fig. 33), compress valve springs and remove
valve locks.
(6) Remove valve spring(s).
(7) Remove valve stem seal(s) by a using valve
stem seal tool (Fig. 35).
REMOVAL - CYLINDER HEAD OFF
(1) With cylinder head removed from cylinder
block, compress valve springs using a universal valve
spring compressor.
(2) Remove valve retaining locks, valve spring
retainers, valve stem seals and valve springs.
(3) Before removing valves,remove any burrs
from valve stem lock grooves to prevent dam-
age to the valve guides.Identify valves, locks and
retainers to insure installation in original location.
(4) Inspect the valves. (Refer to 9 - ENGINE/CYL-
INDER HEAD/VALVE SPRINGS - INSPECTION)
INSPECTION
(1) Whenever valves have been removed for inspec-
tion, reconditioning or replacement, valve springs
should be tested for correct tension. Discard the
springs that do not meet specifications. The following
specifications apply to both intake and exhaust
valves springs:
²Valve Closed Nominal TensionÐ76 lbs. @ 38.0
mm (1.50 in.)
²Valve Open Nominal TensionÐ136 lbs. @ 29.75
mm (1.17 in.)
(2) Inspect each valve spring for squareness with a
steel square and surface plate, test springs from both
ends. If the spring is more than 1.5 mm (1/16 inch)
out of square, install a new spring.
Fig. 32 Cylinder Head Cover Tightening Sequence
(Typical Cover Shown)
Fig. 33 Valve Spring - Removal/Installation
1 - VALVE SPRING COMPRESSOR MD 998772A
2 - AIR HOSE
9 - 32 ENGINE 2.4LRS
CYLINDER HEAD COVER (Continued)
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OIL PAN
REMOVAL
(1) Raise vehicle on hoist and drain engine oil.
(2) Remove structural collar. (Refer to 9 -
ENGINE/ENGINE BLOCK/STRUCTURAL COVER -
REMOVAL)
(3) Remove air conditioning compressor bracket to
oil pan bolt.
(4) Remove bolts attaching oil pan.
(5) Remove oil pan.
(6) Clean oil pan and all gasket surfaces.
INSTALLATION
(1) Apply MopartEngine RTV GEN II at the oil
pump to engine block parting line (Fig. 88).
(2) Install the oil pan gasket to the block.
(3) Install pan and tighten the screws to 12 N´m
(105 in. lbs.).
(4) Install air conditioning compressor bracket to
oil pan bolt.
(5) Install structural collar. (Refer to 9 - ENGINE/
ENGINE BLOCK/STRUCTURAL COVER - INSTAL-
LATION)
(6) Lower vehicle and fill engine crankcase with
proper oil to correct level.
OIL PRESSURE SWITCH
REMOVAL
(1) Raise vehicle.
(2) Position oil collecting container under pressure
switch location.
(3) Disconnect oil pressure switch electrical con-
nector and remove switch (Fig. 89).
INSTALLATION
(1) Install oil pressure switch. Torque switch to 21
N´m (190 in. lbs.) (Fig. 89).
(2) Connect electrical connector
(3) Lower vehicle.
(4) Start engine and allow to run a minimum of 2
minutes.
(5) Shut engine off and check engine oil level.
Adjust level as necessary.
Fig. 87 Oil Filter
Fig. 88 Oil Pan Sealing - Typical
1 - SEALER LOCATIONS
Fig. 89 Engine Oil Pressure Switch
9 - 54 ENGINE 2.4LRS
OIL FILTER (Continued)
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(2) Install camshaft sprockets. Hold sprockets with
Special Tool 6848 and tighten center bolt to 101 N´m
(75 ft. lbs.) (Fig. 112).
(3) Install timing belt idler pulley and tighten
mounting bolt to 61 N´m (45 ft. lbs.) (Fig. 113).
(4) Install timing belt (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT AND SPROCKETS -
INSTALLATION).
(5) Install engine mount bracket and tighten bolts
to 61 N´m (45 ft. lbs.) (Fig. 111).
(6) Install front covers.
TIMING BELT AND
SPROCKET(S)
REMOVAL
REMOVAL - TIMING BELT
(1) Remove air cleaner upper cover, housing, and
clean air tube.
(2) Remove make-up air hose from cylinder head
cover.
(3) Raise vehicle on hoist.
(4) Remove right front wheel.
(5) Remove right inner splash shield.(6) Remove accessory drive belts (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(7) Remove crankshaft vibration damper (Refer to
9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - REMOVAL).
(8) Remove air conditioner/generator belt tensioner
and pulley assembly (Refer to 7 - COOLING/ACCES-
SORY DRIVE/BELT TENSIONERS - REMOVAL).
(9) Remove timing belt lower front cover bolts and
remove cover (Refer to 9 - ENGINE/VALVE TIMING/
TIMING BELT COVER(S) - REMOVAL).
(10) Lower vehicle.
(11) Remove bolts attaching timing belt upper
front cover and remove cover (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT COVER(S) -
REMOVAL).
(12) Remove right engine mount (Refer to 9 -
ENGINE/ENGINE MOUNTING/RIGHT MOUNT -
REMOVAL).
(13) Remove engine mount bracket (Fig. 115).
Fig. 114 Rear Timing Belt Cover Fasteners
1 - M6 BOLTS - 12 N´m (105 in. lbs.)
2 - M8 BOLTS - 28 N´m (250 in. lbs.)
3 - TIMING BELT TENSIONER
Fig. 115 Engine Mount Bracket
1 - ENGINE MOUNT BRACKET
2 - BOLTS - 61 N´m (45 ft. lbs.)
RSENGINE 2.4L9-63
TIMING BELT COVER(S) (Continued)
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