oil change DODGE RAM 2002 Service Repair Manual

COOLANT PERFORMANCE
The required ethylene-glycol (antifreeze) and water
mixture depends upon climate and vehicle operating
conditions. The coolant performance of various mix-
tures follows:
Pure Water-Water can absorb more heat than a
mixture of water and ethylene-glycol. This is for pur-
pose of heat transfer only. Water also freezes at a
higher temperature and allows corrosion.
100 percent Ethylene-Glycol-The corrosion
inhibiting additives in ethylene-glycol need the pres-
ence of water to dissolve. Without water, additives
form deposits in system. These act as insulation
causing temperature to rise to as high as 149ÉC
(300ÉF). This temperature is hot enough to melt plas-
tic and soften solder. The increased temperature can
result in engine detonation. In addition, 100 percent
ethylene-glycol freezes at -22ÉC (-8ÉF).
50/50 Ethylene-Glycol and Water-Is the recom-
mended mixture, it provides protection against freez-
ing to -37ÉC (-34ÉF). The antifreeze concentration
must alwaysbe a minimum of 44 percent, year-
round in all climates. If percentage is lower, engine
parts may be eroded by cavitation. Maximum protec-
tion against freezing is provided with a 68 percent
antifreeze concentration, which prevents freezing
down to -67.7ÉC (-90ÉF). A higher percentage will
freeze at a warmer temperature. Also, a higher per-
centage of antifreeze can cause the engine to over-
heat because specific heat of antifreeze is lower than
that of water.
CAUTION: Richer antifreeze mixtures cannot be
measured with normal field equipment and can
cause problems associated with 100 percent ethyl-
ene-glycol.
COOLANT SELECTION AND ADDITIVES
NOTE: Refer to the vehicle's coolant bottle to iden-
tify HOAT or Non-HOAT coolant. Non-HOAT coolant
is green in color.
The use of aluminum cylinder blocks, cylinder
heads and water pumps requires special corrosion
protection. Only MopartAntifreeze/Coolant, 5
Year/100,000 Mile Formula (glycol base coolant with
corrosion inhibitors called HOAT, for Hybrid Organic
Additive Technology) is recommended. This coolant
offers the best engine cooling without corrosion when
mixed with 50% distilled water to obtain to obtain a
freeze point of -37ÉC (-35ÉF). If it loses color or
becomes contaminated, drain, flush, and replace with
fresh properly mixed coolant solution.CAUTION: Do not use coolant additives that are
claimed to improve engine cooling.
DESCRIPTIONÐENGINE OIL
API SERVICE GRADE CERTIFIED
WARNING: NEW OR USED ENGINE OIL CAN BE
IRRITATING TO THE SKIN. AVOID PROLONGED OR
REPEATED SKIN CONTACT WITH ENGINE OIL.
CONTAMINANTS IN USED ENGINE OIL, CAUSED BY
INTERNAL COMBUSTION, CAN BE HAZARDOUS TO
YOUR HEALTH. THOROUGHLY WASH EXPOSED
SKIN WITH SOAP AND WATER. DO NOT WASH
SKIN WITH GASOLINE, DIESEL FUEL, THINNER, OR
SOLVENTS, HEALTH PROBLEMS CAN RESULT. DO
NOT POLLUTE, DISPOSE OF USED ENGINE OIL
PROPERLY. CONTACT YOUR DEALER OR GOVERN-
MENT AGENCY FOR LOCATION OF COLLECTION
CENTER IN YOUR AREA.
Standard engine-oil identification notations have
been adopted to aid in the proper selection of engine
oil. The identifying notations are located on the label
of engine oil plastic bottles and the top of engine oil
cans.
In diesel engines, use an engine oil that conforms
to API Service Grade CF-4 or CG-4/SH (Fig. 3).
MOPARtprovides an engine oil that conforms to this
particular grade.
SAE VISCOSITY
An SAE viscosity grade is used to specify the vis-
cosity of engine oil. SAE 15W±40 specifies a multiple
viscosity engine oil.
When choosing an engine oil, consider the range of
temperatures the vehicle will be operated in before
the next oil change. Select an engine oil that is best
suited to your area's particular ambient temperature
range and variation. For diesel engines, refer to (Fig.
4).
Fig. 3 API Service Grade Certification LabelÐDiesel
Engine Oil
0 - 4 LUBRICATION & MAINTENANCEBR/BE
FLUID TYPES (Continued)

DESCRIPTION - AUTOMATIC TRANSMISSION
FLUID
NOTE: Refer to the maintenance schedules in this
group for the recommended maintenance (fluid/filter
change) intervals for this transmission.
NOTE: Refer to Service Procedures in this group for
fluid level checking procedures.
MopartATF +4, type 9602, Automatic Transmis-
sion Fluid is the recommended fluid for
DaimlerChrysler automatic transmissions.
Dexron II fluid IS NOT recommended. Clutch
chatter can result from the use of improper
fluid.
MopartATF +4, type 9602, Automatic Transmis-
sion Fluid when new is red in color. The ATF is dyed
red so it can be identified from other fluids used in
the vehicle such as engine oil or antifreeze. The red
color is not permanent and is not an indicator of fluid
condition. As the vehicle is driven, the ATF will begin
to look darker in color and may eventually become
brown.This is normal.A dark brown/black fluid
accompanied with a burnt odor and/or deterioration
in shift quality may indicate fluid deterioration or
transmission component failure.
FLUID ADDITIVES
DaimlerChrysler strongly recommends against the
addition of any fluids to the transmission, other than
those automatic transmission fluids listed above.
Exceptions to this policy are the use of special dyes
to aid in detecting fluid leaks.
Various ªspecialº additives and supplements exist
that claim to improve shift feel and/or quality. These
additives and others also claim to improve converter
clutch operation and inhibit overheating, oxidation,
varnish, and sludge. These claims have not been sup-
ported to the satisfaction of DaimlerChrysler and
these additivesmust not be used.The use of trans-
mission ªsealersº should also be avoided, since they
may adversely affect the integrity of transmission
seals.
OPERATION - AUTOMATIC TRANSMISSION
FLUID
The automatic transmission fluid is selected based
upon several qualities. The fluid must provide a high
level of protection for the internal components by
providing a lubricating film between adjacent metal
components. The fluid must also be thermally stable
so that it can maintain a consistent viscosity through
a large temperature range. If the viscosity stays con-
stant through the temperature range of operation,transmission operation and shift feel will remain con-
sistent. Transmission fluid must also be a good con-
ductor of heat. The fluid must absorb heat from the
internal transmission components and transfer that
heat to the transmission case.
FLUID CAPACITIES
SPECIFICATIONS
FLUID CAPACITIES
DESCRIPTION SPECIFICATION
FUEL TANK
2500 Series Club Cab
and Quad Cab with 6.5'
Short Box129 L (34 gal.)*****
All 8' Long Box 132 L (35 gal.)*****
All Cab/Chassis Models 132 L (35 gal.)*****
ENGINE OIL WITH FILTER
5.9L 4.7 L (5.0 qts.)
8.0L 6.6 L (7.0 qts.)
5.9L DIESEL 10.4 L (11.0 qts.)
COOLING SYSTEM
5.9L 19 L (20 qts.)****
8.0L 24.5 L (26.0 qts.)****
5.9L DIESEL 22.7 L (24.0 qts.)****
POWER STEERING
Power steering fluid capacities are dependent on
engine/chassis options as well as steering gear/cooler
options. Depending on type and size of internal
cooler, length and inside diameter of cooler lines, or
use of an auxiliary cooler, these capacities may vary.
Refer to 19, Steering for proper fill and bleed
procedures.
AUTOMATIC TRANSMISSION
Service Fill - 46RE 3.8 L (4.0 qts.)
O-haul - 46RE 9-9.5L (19-20 pts.)*
Service Fill - 47RE 3.8 L (4.0 qts.)
O-haul - 47RE 14-16 L (29-33 pts.)*
0 - 6 LUBRICATION & MAINTENANCEBR/BE
FLUID TYPES (Continued)

CORRECTED CASTER CHART-CAB CHASSIS
Caster
Correlation
Value
(inches)4x2 8800
lb. GVW
134.7 in.
wheel
base4x4 8800
lb. GVW
4x2 & 4x4
11000 lb.
GVW
134.7 &
138.7 in.
wheel
base4x2 & 4x4
11000 lb.
GVW 162.7
in. wheel
base
Caster   1
deg.Caster   1
deg.Caster   1
deg.
25.00 4.27É 3.77É 3.81É
24.75 4.39É 3.89É 3.91É
24.50 4.51É 4.01É 4.01É
24.25 4.64É 4.14É 4.11É
24.00 4.76É 4.26É 4.21É
23.75 4.88É 4.38É 4.31É
23.50 5.00É 4.50É 4.41É
23.25 5.12É 4.62É 4.51É
23.00 5.25É 4.75É 4.61É
22.75 5.37É 4.87É 4.71É
22.50 5.49É 4.99É 4.81É
22.25 5.61É 5.11É 4.91É
22.00 5.74É 5.24É 5.01É
21.75 5.86É 5.36É 5.11É
21.50 5.98É 5.48É 5.21É
21.25 6.10É 5.60É 5.31É
21.00 6.23É 5.73É 5.41É
20.75 6.33É 5.83É 5.51É
20.50 6.47É 5.97É 5.61É
20.25 6.59É 6.09É 5.71É
0.00 6.71É 6.21É 5.81É
STANDARD PROCEDURE - ALIGNMENT
LINK/COIL SUSPENSION
Before each alignment reading the vehicle should
be jounced (rear first, then front). Grasp each
bumper at the center and jounce the vehicle up and
down several times. Always release the bumper in
the down position.Set the front end alignment to
specifications while the vehicle is in its NOR-
MALLY LOADED CONDITION.
CAMBER:The wheel camber angle is preset and
is not adjustable.
CASTER:Check the caster of the front axle for
correct angle. Be sure the axle is not bent or twisted.Road test the vehicle and make left and right turn.
Observe the steering wheel return-to-center position.
Low caster will cause poor steering wheel returnabil-
ity.
Caster can be adjusted by rotating the cams on the
lower suspension arm (Fig. 5). (Refer to 2 - SUSPEN-
SION/WHEEL ALIGNMENT - STANDARD PROCE-
DURE).
TOE POSITION:The wheel toe position adjust-
ment should be the final adjustment.
(1) Start the engine and turn wheels both ways
before straightening the wheels. Center and Secure
the steering wheel and turn off engine.
(2) Loosen the adjustment sleeve clamp bolts.
(3) Adjust the right wheel toe position with the
drag link. Turn the sleeve until the right wheel is at
the correct TOE-IN position. Position clamp bolts to
their original position and tighten to specifications.
Make sure the toe setting does not change dur-
ing clamp tightening.
(4) Adjust left wheel toe position with tie rod at
left knuckle. Turn the sleeve until the left wheel is at
the correct TOE-IN position. Position clamp bolts to
their original position and tighten to specifications.
Make sure the toe setting does not change dur-
ing clamp tightening.
(5) Verify the right toe setting.
Fig. 5 Adjustment Cam
1 - ADJUSTMENT CAM
2 - AXLE BRACKET
3 - BRACKET REINFORCEMENT
4 - LOWER SUSPENSION ARM
BR/BEWHEEL ALIGNMENT 2 - 5
WHEEL ALIGNMENT (Continued)

If a new gear set is being installed, note the depth
variance etched into both the original and replace-
ment pinion. Add or subtract this number from the
thickness of the original depth shim/oil slinger to
compensate for the difference in the depth variances.
Refer to the Depth Variance chart.
Note where Old and New Pinion Marking columns
intersect. Intersecting figure represents plus or
minus the amount needed.Note the etched number on the face of the pinion
gear head (±1, ±2, 0, +1, +2, etc.). The numbers rep-
resent thousands of an inch deviation from the stan-
dard. If the number is negative, add that value to the
required thickness of the depth shims. If the number
is positive, subtract that value from the thickness of
the depth shim. If the number is 0 no change is nec-
essary.
PINION GEAR DEPTH VARIANCE
Original Pinion
Gear Depth
VarianceReplacement Pinion Gear Depth Variance
24232221 0 +1 +2 +3 +4
+4+0.008 +0.007 +0.006 +0.005 +0.004 +0.003 +0.002 +0.001 0
+3+0.007 +0.006 +0.005 +0.004 +0.003 +0.002 +0.001 020.001
+2+0.006 +0.005 +0.004 +0.003 +0.002 +0.001 020.00120.002
+1+0.005 +0.004 +0.003 +0.002 +0.001 020.00120.00220.003
0+0.004 +0.003 +0.002 +0.001 020.00120.00220.00320.004
21+0.003 +0.002 +0.001 020.00120.00220.00320.00420.005
22+0.002 +0.001 020.00120.00220.00320.00420.00520.006
23+0.001 020.00120.00220.00320.00420.00520.00620.007
24020.00120.00220.00320.00420.00520.00620.00720.008
3 - 20 FRONT AXLE - 248FBIBR/BE
FRONT AXLE - 248FBI (Continued)

(3) Install shock absorbers and tighten to specifica-
tions.
(4) Install RWAL sensor to the differential hous-
ing, if necessary.
(5) Install parking brake cables and cable brackets
(6) Install brake hose to the axle junction block.
(7) Install axle vent hose.
(8) Install propeller shaft with reference marks
aligned.
(9) Install wheels and tires assemblies.
(10) Add gear lubricant, if necessary.
(11) Remove lift from the axle and lower the vehi-
cle.
ADJUSTMENTS
Ring and pinion gears are supplied as matched
sets only. The identifying numbers for the ring and
pinion gear are etched onto each gear (Fig. 4). A plus
(+) number, minus (±) number or zero (0) is etched
onto the pinion gear. This number is the amount (in
thousandths of an inch) the depth varies from the
standard depth setting of a pinion etched with a (0).
The standard setting from the center line of the ring
gear to the back face of the pinion is 136.53 mm
(5.375 in.). The standard depth provides the best
gear tooth contact pattern. Refer to Backlash and
Contact Pattern in this section for additional infor-
mation.
Compensation for pinion depth variance is
achieved with a select shim/oil baffle. The shims are
placed between the rear pinion bearing and the pin-
ion gear head (Fig. 5).
If a new gear set is being installed, note the depth
variance etched into both the original and replace-
ment pinion. Add or subtract this number from the
thickness of the original depth shim/oil slinger to
compensate for the difference in the depth variances.
Refer to the Depth Variance chart.
Note where Old and New Pinion Marking columns
intersect. Intersecting figure represents plus or
minus the amount needed.
Note the etched number on the face of the pinion
gear head (±1, ±2, 0, +1, +2, etc.). The numbers rep-
resent thousands of an inch deviation from the stan-
dard. If the number is negative, add that value to the
required thickness of the depth shims. If the number
is positive, subtract that value from the thickness of
the depth shim. If the number is 0 no change is nec-
essary.Fig. 4 PINION GEAR ID NUMBERS
1 - PRODUCTION NUMBERS
2 - PINION GEAR DEPTH VARIANCE
3 - GEAR MATCHING NUMBER
Fig. 5 SHIM LOCATIONS
1 - PINION GEAR DEPTH SHIM/OIL BAFFLE
2 - DIFFERENTIAL BEARING SHIM
BR/BEREAR AXLE - 267RBI 3 - 83
REAR AXLE - 267RBI (Continued)

(3) Install front pinion bearing cup with Installer
D-146 and Handle C-4171 (Fig. 53) and verify cup is
seated.
(4) Install pinion front bearing and oil slinger, if
equipped. Apply a light coating of gear lubricant on
the lip of pinion seal.
(5) Install anewpinion seal with an appropriate
installer (Fig. 54).
NOTE: Pinion depth shims are placed between the
rear pinion bearing cone and pinion gear to achieve
proper ring and pinion gear mesh. If ring and pinion
gears are reused, the pinion depth shim should not
require replacement. If the ring and pinion gears are
replaced refer to Adjustments (Pinion Gear Depth )
to select the proper thickness shim.
(6) Place the proper thickness pinion depth shim
on the pinion gear.(7) Install rear bearing and oil slinger, if equipped
on the pinion gear with Installer C-3095-A and a
press (Fig. 55).
(8) Install original solid shims on pinion gears.
(9) Install yoke with Installer C-3718 and Yoke
Holder 6719A (Fig. 56).
(10) Install the yoke washer andnewnut on the
pinion gear. Tighten the nut to 298-380 N´m (220-280
ft. lbs.).
(11) Check bearing rotating torque with an inch
pound torque wrench (Fig. 57). Pinion rotating torque
should be:
²Original Bearings: 1 to 3 N´m (10 to 20 in. lbs.).
²New Bearings: 2.3 to 5.1 N´m (20 to 45 in. lbs.).
(12) If rotating torque is less than the desired
rotating torque, remove the pinion yoke and decrease
the thickness of the solid shim pack if greater
increase shim pack. Changing the shim pack thick-
ness by 0.025 mm (0.001 in.) will change the rotating
torque approximately 0.9 N´m (8 in. lbs.).
Fig. 53 FRONT PINION BEARING CUP
1 - INSTALLER
2 - HANDLE
Fig. 54 PINION SEAL
1 - HANDLE
2 - INSTALLER
Fig. 55 REAR PINION BEARING
1 - PRESS
2 - INSTALLER
3 - PINION GEAR
4 - PINION BEARING
BR/BEREAR AXLE - 267RBI 3 - 105
PINION GEAR/RING GEAR/TONE RING (Continued)

CAUTION: If the caliper piston is replaced, install
the same type of piston in the caliper. Never inter-
change phenolic resin and steel caliper pistons.
The pistons, seals, seal grooves, caliper bore and
piston tolerances are different.
The bore can belightlypolished with a brake
hone to remove very minor surface imperfections
(Fig. 14). The caliper should be replaced if the bore is
severely corroded, rusted, scored, or if polishing
would increase bore diameter more than 0.025 mm
(0.001 inch).
ASSEMBLY
CAUTION: Dirt, oil, and solvents can damage cali-
per seals. Insure assembly area is clean and dry.
(1) Lubricate caliper pistons, piston seals and pis-
ton bores with clean, fresh brake fluid.
(2) Install new piston seals into caliper bores (Fig.
15).
NOTE: Verify seal is fully seated and not twisted.
(3) Lightly lubricate lip of new boot with silicone
grease. Install boot on piston and work boot lip into
the groove at the top of piston.
(4) Stretch boot rearward to straighten boot folds,
then move boot forward until folds snap into place.
(5) Install piston into caliper bore and press piston
down to the bottom of the caliper bore by hand or
with hammer handle (Fig. 16).
(6) Seat dust boot in caliper (Fig. 17) with Handle
C-4171 and Installer:
²HD 56 mm caliper: Installer C-4340
²LD 54 mm caliper: Installer C-3716-A
(7) Install the second piston and dust boot.
(8) Lubricate caliper mounting bolt bushings, boot
seals and bores with Mopar brake grease or Dow
Corningt807 grease only.
CAUTION: Use of alternative grease may cause
damage to the boots seals.
(9) Install the boot seals into the caliper seal bores
and center the seals in the bores.
Fig. 13 Bushings And Boot Seals
1 - CALIPER
2 - BUSHING
3 - BOOT SEAL
Fig. 14 Polishing Piston Bore
1 - HONE
2 - CALIPER
3 - PISTON BORE
Fig. 15 Piston Seal
1 - CALIPER
2 - PISTON BORE
3 - PISTON SEAL
BR/BEBRAKES - BASE 5 - 13
DISC BRAKE CALIPERS (Continued)

Starter Motor and Solenoid
Solenoid Closing Maximum
Voltage Required7.5 Volts 7.5 Volts 8.0 Volts
* Cranking Amperage Draw
Test125 - 250 Amperes 125 - 250 Amperes 450 - 700 Amperes
* Test at operating temperature. Cold engine, tight (new) engine, or heavy oil will increase starter amperage draw.
SPECIFICATIONS - TORQUE - STARTING
SYSTEM
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Battery Cable Eyelet Nut
at Solenoid (large nut -
gas engines)25 19 221
Battery Cable Eyelet Nut
at Solenoid (large nut -
diesel engine)14 - 120
Starter Solenoid Nut
(small nut - diesel engine)6-55
Starter Mounting Bolts -
Gas Engines68 50 -
Starter Mounting Nut -
Gas Engines68 50 -
Starter Mounting Bolts -
Diesel43 32 -
STARTER MOTOR
DESCRIPTION
The starter motors used for the 5.9L diesel engine
and the 8.0L gasoline engine available in this model
are not interchangeable with each other, or with the
starter motors used for the other available engines.
The starter motor for the 5.9L diesel engine is
mounted with three screws to the flywheel housing
on the left side of the engine. The starter motor for
the 8.0L gasoline engine is mounted with two screws
to the flange on the left rear corner of the engine
block, while the starter motor for the 5.9L Gas
engine is mounted with one screw, a stud and a nut
to the manual transmission clutch housing or auto-
matic transmission torque converter housing and is
located on the left side of the engine.
Each of these starter motors incorporates several
of the same features to create a reliable, efficient,
compact, lightweight and powerful unit. The electric
motors of all of these starters have four brushes con-
tacting the motor commutator, and feature four elec-
tromagnetic field coils wound around four pole shoes.
The 5.9L and 8.0L gasoline engine starter motors are
rated at 1.4 kilowatts (about 1.9 horsepower) outputat 12 volts, while the 5.9L diesel engine starter
motor is rated at 2.7 kilowatts (about 3.6 horse-
power) output at 12 volts.
All of these starter motors are serviced only as a
unit with their starter solenoids, and cannot be
repaired. If either component is faulty or damaged,
the entire starter motor and starter solenoid unit
must be replaced.
OPERATION
These starter motors are equipped with a gear
reduction (intermediate transmission) system. The
gear reduction system consists of a gear that is inte-
gral to the output end of the electric motor armature
shaft that is in continual engagement with a larger
gear that is splined to the input end of the starter
pinion gear shaft. This feature makes it possible to
reduce the dimensions of the starter. At the same
time, it allows higher armature rotational speed and
delivers increased torque through the starter pinion
gear to the starter ring gear.
The starter motors for all engines are activated by
an integral heavy duty starter solenoid switch
mounted to the overrunning clutch housing. This
electromechanical switch connects and disconnects
BR/BESTARTING 8F - 37
STARTING (Continued)

REMOVAL - 8.0L
Two separate coil packs containing a total of five
independent coils are attached to a common mount-
ing bracket located above the right engine valve
cover (Fig. 26). The front and rear coil packs can be
serviced separately.
(1) Remove the secondary spark plug cables from
the coil packs. Note position of cables before removal.
(2) Disconnect the primary wiring harness connec-
tors at coil packs.(3) Remove the four (4) coil pack-to-coil mounting
bracket bolts for the coil pack being serviced (Fig.
26).
(4) Remove coil(s) from mounting bracket.
INSTALLATION
INSTALLATION - 5.9L
The ignition coil is an epoxy filled type. If the coil
is replaced, it must be replaced with the same type.
(1) Install the ignition coil to coil bracket. If nuts
and bolts are used to secure coil to coil bracket,
tighten to 11 N´m (100 in. lbs.) torque. If the coil
mounting bracket has been tapped for coil mounting
bolts, tighten bolts to 5 N´m (50 in. lbs.) torque.
(2) Connect all wiring to ignition coil.
INSTALLATION - 8.0L
(1) Position coil packs to mounting bracket (prima-
ry wiring connectors face downward).
(2) Install coil pack mounting bolts. Tighten bolts
to 10 N´m (90 in. lbs.) torque.
(3) Install coil pack-to-engine mounting bracket (if
necessary).
(4) Connect primary wiring connectors to coil
packs (four wire connector to front coil pack and
three wire connector to rear coil pack).
(5) Connect secondary spark plug cables to coil
packs. Refer to (Fig. 27) for correct cable order.
SPARK PLUG
DESCRIPTION
The 5.9L V-8 engines use resistor type spark plugs.
The 8.0L V-10 engine uses inductive type spark
plugs.
Spark plug resistance values range from 6,000 to
20,000 ohms (when checked with at least a 1000 volt
spark plug tester).Do not use an ohmmeter to
check the resistance values of the spark plugs.
Inaccurate readings will result.
OPERATION
To prevent possible pre-ignition and/or mechanical
engine damage, the correct type/heat range/number
spark plug must be used.
Always use the recommended torque when tighten-
ing spark plugs. Incorrect torque can distort the
spark plug and change plug gap. It can also pull the
plug threads and do possible damage to both the
spark plug and the cylinder head.
Remove the spark plugs and examine them for
burned electrodes and fouled, cracked or broken por-
celain insulators. Keep plugs arranged in the order
Fig. 25 Ignition CoilÐ5.9L V-8 HDC-Gas Engine
1 - COIL MOUNTING BOLTS
2 - IGNITION COIL
3 - COIL ELEC. CONNECTOR
4 - SECONDARY CABLE
Fig. 26 Ignition Coil PacksÐ8.0L V-10 Engine
8I - 16 IGNITION CONTROLBR/BE
IGNITION COIL (Continued)

cause of oil entry into that particular combustion
chamber.
ELECTRODE GAP BRIDGING
Electrode gap bridging may be traced to loose
deposits in the combustion chamber. These deposits
accumulate on the spark plugs during continuous
stop-and-go driving. When the engine is suddenly
subjected to a high torque load, deposits partially liq-
uefy and bridge the gap between electrodes (Fig. 30).
This short circuits the electrodes. Spark plugs with
electrode gap bridging can be cleaned using standard
procedures.
SCAVENGER DEPOSITS
Fuel scavenger deposits may be either white or yel-
low (Fig. 31). They may appear to be harmful, but
this is a normal condition caused by chemical addi-
tives in certain fuels. These additives are designed to
change the chemical nature of deposits and decrease
spark plug misfire tendencies. Notice that accumula-
tion on the ground electrode and shell area may be
heavy, but the deposits are easily removed. Spark
plugs with scavenger deposits can be considered nor-
mal in condition and can be cleaned using standard
procedures.
CHIPPED ELECTRODE INSULATOR
A chipped electrode insulator usually results from
bending the center electrode while adjusting the
spark plug electrode gap. Under certain conditions,
severe detonation can also separate the insulator
from the center electrode (Fig. 32). Spark plugs with
this condition must be replaced.
PREIGNITION DAMAGE
Preignition damage is usually caused by excessive
combustion chamber temperature. The center elec-
trode dissolves first and the ground electrode dis-
solves somewhat latter (Fig. 33). Insulators appear
relatively deposit free. Determine if the spark plug
has the correct heat range rating for the engine.
Determine if ignition timing is over advanced or if
other operating conditions are causing engine over-
heating. (The heat range rating refers to the operat-
ing temperature of a particular type spark plug.
Spark plugs are designed to operate within specific
temperature ranges. This depends upon the thick-
ness and length of the center electrodes porcelain
insulator.)
Fig. 29 Oil or Ash Encrusted
Fig. 30 Electrode Gap Bridging
1 - GROUND ELECTRODE
2 - DEPOSITS
3 - CENTER ELECTRODE
Fig. 31 Scavenger Deposits
1 - GROUND ELECTRODE COVERED WITH WHITE OR
YELLOW DEPOSITS
2 - CENTER ELECTRODE
8I - 18 IGNITION CONTROLBR/BE
SPARK PLUG (Continued)