(Refer to 9 - ENGINE - DIAGNOSIS AND TESTING) - PERFORMANCE and (Refer to 9 - ENGINE - DIAGNOSIS
AND TESTING)—MECHANICAL for possible causes and corrections of malfunctions. (Refer to 14 - FUEL SYSTEM/
FUEL DELIVERY - DIAGNOSIS AND TESTING) and (Refer to 14 - FUEL SYSTEM/FUEL INJECTION - DIAGNO-
SIS AND TESTING) for the fuel system diagnosis.
Additional tests and diagnostic procedures may be necessary for specificengine malfunctions that can not be iso-
lated with the Service Diagnosis charts. Information concerning additional tests and diagnosis is provided within the
following diagnosis:
Cylinder Compression Pressure Test (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
Cylinder Combustion Pressure LeakageTest (Refer to 9 - ENGINE - DIAGNOSISAND TESTING).
Engine Cylinder Head Gasket Failure Diagnosis (Refer to 9 - ENGINE/CYLINDER HEAD - DIAGNOSIS AND
TESTING).
Intake Manifold Leakage Diagnosis (Refer to 9 - ENGINE/MANIFOLDS/INTAKEMANIFOLD - DIAGNOSIS
AND TESTING).
DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - PERFORMANCE
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE WILL NOT START 1. Weak battery 1. Charge or replace as necessary.
2. Corroded or loose battery
connections.2. Clean and tighten battery
connections. Apply a coat of light
mineral grease to the terminals.
3. Faulty starter. 3. (Refer to 8 - ELECTRICAL/
STARTING - DIAGNOSIS AND
TESTING).
4. Faulty coil or control unit. 4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
5. Incorrect spark plug gap. 5. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG
- CLEANING).
6. Incorrect right bank cam timing. 6. Refer to engine timing in this
section.
7. Dirt or water in fuel system. 7. Clean system and replace fuel
filter.
8.Faulty fuel pump, relay or wiring. 8.Repair or replace as necessary.
9. Faulty cam or crank sensor 9. Refer to Ignition system.
ENGINE STALLS OR ROUGH IDLE 1. Vacuum leak. 1. Inspect intake manifold and
vacuum hoses, repair or replace as
necessary.
2. Faulty crank position sensor 2. Replace crank position sensor.
3. Faulty coil. 3. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
4. Incorrect cam timing. 4. (Refer to 9 - ENGINE/VALVE
TIMING - STANDARD
PROCEDURE).
VALVES & SEATS - INTAKE/EXHAUST
DESCRIPTION
The valves are made of heat resistant steel and have chrome plated stems to prevent scuffing. Each valve is actu-
ated 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 (4) and valve seats, it
is important that the correct size valve guide pilot
be used for reseating stones. A true and complete
surface 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 bot-
tom 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 (6) installed height after refacing the valve andseat. The installed height for both intake
and exhaust valve springs must not exceed 40.74 mm (1.6039 in.).
5. The valve seat and valve face must maintain a face angle of 44.5 - 45 ° angle.
BLOCK-ENGINE
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 isbolted 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 limits.
CAUTION: DO NOT use rigid type hones to remove
cylinder wall glaze.
2. Deglazing of the cylinder walls may be done if the
cylinder bore is straight and round. Use a cylinder
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
sufficient to provide a satisfactory surface. Using
honing oil C-3501-3880, or a light honing oil, avail-
able from major oil distributors.
CAUTION: DO NOT use engine or transmission oil, mineral spirits, or kerosene.
3. Honing should be done by moving the hone up and down fast enough to get a crosshatch pattern (1). The hone
marks should INTERSECT at 50° to 60° for proper seating of rings (2).
4. A controlled hone motor speed between 200 and 300 RPM is necessary to obtain the proper crosshatch angle.
The number of up and down strokes per minute can be regulated to get the desired 50° to 60° angle. Faster up
and down strokes increase the crosshatch angle.
5. After honing, it is necessary that the block be cleaned to remove all traces of abrasive. Use a brush to wash
parts with a solution of hot water and detergent. Dry parts thoroughly. Usea clean, white, lint-free cloth to check
that the bore is clean. Oil the bores after cleaning to prevent rusting.
CLEANING
Thoroughly clean the oil pan and engine block gasket surfaces.
Use compressed air to clean out:
The galley at the oil filter adaptor hole.
The front and rear oil galley holes.
The feed holes for the crankshaft main bearings.
Once the block has been completely cleaned, apply Loctite PST pipe sealantwith Teflon 592 to the threads of the
front and rear oil galley plugs. Tighten the 1/4 inch NPT plugs to 20 Nꞏm (177in. lbs.) torque. Tighten the 3/8 inch
NPT plugs to 27 Nꞏm (240 in. lbs.) torque.
INSPECTION
1. It is mandatory to use a dial bore gauge to mea-
sure each cylinder bore diameter. To correctly
select the proper size piston, a cylinder bore
gauge, capable of reading in 0.003 mm (.0001 in.)
INCREMENTS is required. If a bore gauge is not
available, do not use an inside micrometer.
2. Measure the inside diameter of the cylinder bore at
three levels below top of bore. Start perpendicular
(across or at 90 degrees) to the axis of the crank-
shaft and then take two additional reading.
3. Measure the cylinder bore diameter crosswise to
the cylinder block near the top of the bore. Repeat
the measurement near the middle of the bore, then
repeat the measurement near the bottom of the
bore.
4. Determine taper by subtracting the smaller diame-
ter from the larger diameter.
5. Rotate measuring device 90° and repeat steps
above.
6. Determine out-of-roundness by comparing the dif-
ference between each measurement.
7. If cylinder bore taper does not exceed 0.025 mm (0.001 inch) and out-of-roundness does not exceed 0.015 mm
(0.0006 inch), the cylinder bore can be honed. If the cylinder bore taper orout- of-round condition exceeds these
maximum limits, the cylinder block must be replaced. A slight amount of taper always exists in the cylinder bore
after the engine has been in use for a period of time.
SEAL-CRANKSHAFT OIL-REAR
DIAGNOSIS AND TESTING - REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the source of an oil leak in therear seal area of the engine, a more
involved inspection is necessary. The following steps should be followedto 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:
a. Circular spray pattern generally indicates seal leakage or crankshaftdamage.
b. Where leakage tends to run straight down, possible causes are a porous block, oil galley pipe plugs, oil filter
runoff, and main bearing cap to cylinder block mating surfaces. See Engine, for proper repair procedures of
these items.
4. If no leaks are detected, pressurized the crankcase as outlined in the section, Inspection (Engine oil Leaks in
general)
CAUTION: Do not exceed 20.6 kPa (3 psi).
5. If the leak is not detected, very slowly turn the crankshaft and watch forleakage. 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 canbe polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft polishing is necessary to remove minor nicks or
scratches. The crankshaft seal flange is specially 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 disassembled. (Refer
to 9 - ENGINE - DIAGNOSIS AND TESTING), under the Oil Leak row, for components inspections on possible
causes and corrections.
7. After the oil leak root cause and appropriate corrective action have been identified, (Refer to 9 - ENGINE/EN-
GINE BLOCK/CRANKSHAFT OIL SEAL - REAR - REMOVAL).
REMOVAL
NOTE: This procedure can be performed in vehi-
cle.
1. If being performed in vehicle, remove the transmis-
sion.
2. Remove the flexplate (Refer to 9 - ENGINE/EN-
GINE BLOCK/FLEX PLATE - REMOVAL).
NOTE: The crankshaft oil seal CAN NOT be reused
after removal.
NOTE: The crankshaft rear oil seal remover Spe-
cial Tool 8506 must be installed deeply into the
seal. Continue to tighten the removal tool into the
seal until the tool can not be turned farther. Fail-
ure to install tool correctly the first time will cause
tool to pull free of seal without removing seal from
engine.
3. Using Special Tool 8506 (2), remove the crankshaft rear oil seal (1)
Slide snug-fitting feeler gauge between the connecting
rod and crankshaft journal flange. Refer to Engine
Specifications for the proper clearance. Replace the
connecting rod if the side clearance is not within
specification.
STANDARD PROCEDURE - PISTON FITTING
1. To correctly select the proper size piston, a cylinder
bore gauge (2), capable of reading in 0.003 mm (
.0001 in.) INCREMENTS is required. If a bore
gauge is not available, do not use an inside
micrometer.
2. Measure the inside diameter of the cylinder bore
(3) at a point 38.0 mm (1.5 inches) below top of
bore. Start perpendicular (across or at 90 degrees)
to the axis of the crankshaft at point A and then
take an additional bore reading 90 degrees to that
at point B.
3. The coated pistons (1,2) will be serviced with the
piston pin and connecting rod pre-assembled.
4. The coating material is applied to the piston after
the final piston machining process. Measuring the
outside diameter of a coated piston (1,2) will not
provide accurate results. Therefore measuring the
inside diameter of the cylinder bore with a dial Bore
Gauge isMANDATORY. To correctly select the
proper size piston, a cylinder bore gauge capable
of reading in 0.003 mm (.0001 in.) increments is
required.
5. Piston installation intothe cylinder bore requires
slightly more pressure than that required for non-
coated pistons. The bonded coating on the piston
will give the appearance of a line-to-line fit with the
cylinder bore.
INSTALLATION
CAUTION: To prevent severe damage to the Crank-
shaft, Damper or Special Tool 8512–A, thoroughly
clean the damper bore and the crankshaft nose
before installing Damper.
1. Align crankshaft damper slot with key in crankshaft.
Slide damper onto crankshaft slightly.
CAUTION: Special Tool 8512–A, is assembled in a
specific sequence. Failure to assemble this tool in
this sequence can result in tool failure and severe
damage to either the tool or the crankshaft.
2. Assemble Special Tool 8512–A as follows, The nut
(2) is threaded onto the shaft first. Then the roller
bearing (1) is placed onto the threaded rod (3)
(The hardened bearing surface of the bearing (1)
MUSTface the nut (2). Then the hardened washer (5) slides onto the threaded rod.Once assembled coat the
threaded rod’s threads with Mopar
Nickel Anti-Seize or equivalent.
3. Using Special Tool 8512–A, press damper onto
crankshaft (1).
4. Install then tighten crankshaft damper bolt to 175
Nꞏm (130 ft. lbs.).
5. Install fan blade assembly (Refer to 7 - COOLING/
ENGINE/FAN DRIVE VISCOUS CLUTCH -
INSTALLATION).
6. Install radiator upper shroud and tighten fasteners
to 11 Nꞏm (95 in. lbs.).
7. Connect electrical connector for shroud fan.
8. Install radiator upper hose.
9. Install accessory drive belt (Refer to 7 - COOLING/
ACCESSORY DRIVE/DRIVE BELTS - INSTALLA-
TION).
10. Refill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
11. Connect negative cable to battery.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE OIL LEAK
Begin with a thorough visual inspection of the engine, particularly at thearea of the suspected leak. If an oil leak
source is not readily identifiable, thefollowingstepsshouldbefollowed:
1. Do not clean or degrease the engine at this time because some solvents maycause 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 per service manual instructions.
4. If dye is not observed, drive the vehicle at various speeds for approximately 24 km (15 miles), and repeat inspec-
tion.If the oil leak source is not positively identified at this time, proceed with the air leak detection test method.
Air Leak Detection Test Method
1. Disconnect the breather cap to air cleaner hose at the breather cap end. Cap or plug breather cap nipple.
2. Remove the PCV valve from the cylinder head cover. Cap or plug the PCV valvegrommet.
3. Attach an air hose with pressure gauge and regulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to more than 20.6 kPa (3 PSI) of test pressure.
4. Gradually apply air pressure from 1 psi to 2.5 psi maximum while applyingsoapy water at the suspected source.
Adjust the regulator to the suitable test pressure that provide the best bubbles which will pinpoint the leak
source. If the oil leak is detected and identified, repair per service manual procedures.
5. If the leakage occurs at the 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 and remove the air hose and all plugs and caps. Install the PCV
valve and breather cap hose.
7. Clean the oil off the suspect oil leak area using a suitable solvent. Drive the vehicle at various speeds approx-
imately 24 km (15 miles). Inspect the engine for signs of an oil leak by usinga black light.
INSPECTION FOR REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the source of an oil leak in therear seal area of the engine, a more
involved inspection is necessary. The following steps should be followedto 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:
a. Circular spray pattern generally indicates seal leakage or crankshaftdamage.
b. Where leakage tends to run straight down, possible causes are a porous block, oil galley pipe plugs, oil filter
runoff, and main bearing cap to cylinder block mating surfaces.
4. If no leaks are detected, pressurize the crankcase as outlined in the, Inspection (Engine oil Leaks in general)
CAUTION: Do not exceed 20.6 kPa (3 psi).
5. If the leak is not detected, very slowly turn the crankshaft and watch forleakage. 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 canbe 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 disassembled.