2003 FORD MUSTANG light

z
Excessive runout of
valve seats on the
valve face. z
CARRY OUT a valve seat
runout test. INSPECT the
valve face and seat.
INSTALL new valves as
necessary. REFER to
Section 303 - 01A for 3.8L
engines or Section 303 - 01B
for 4.6L (2V) engines.
z Rattling noise—
from the bottom
of the vehicle z
Loose muffler shields
or catalytic converter
shields. z
CHECK the exhaust
system for loose exhaust
shields. REPAIR as
necessary.
z Thumping
noise— from the
bottom of the
vehicle, worse at
acceleration z
Exhaust pipe/muffler
grounded to chassis. z
CHECK the exhaust
system to chassis
clearance. CHECK the
exhaust system hangers for
damage. REPAIR as
necessary. REFER to
Section 309 - 00 .
z Whoosh— occurs
during light
vehicle
acceleration.
Heard inside the
vehicle z
Throttling late,
creating turbulence
transmitted through
the plastic manifold. z
CHECK for leaks or
missing seal in the dash
panel.
z Engine
vibration—
increases
intensity as
engine rpm is
increased z
Engine out-of-
balance. z
CARRY OUT Neutral
Engine Run- Up (NERU)
Test. ROTATE the torque
converter, 120° for 3 bolt
and 180° for 4 bolt.
INSPECT the torque
converter pilot outer
diameter to crankshaft pilot
inner diameter. REPAIR as
necessary. REFER to
Section 307 - 01 .
z Engine
vibration— is felt
with increases
and decreases in
engine rpm z
Strain on exhaust
mounts. z
CARRY OUT the Exhaust
System Neutralizing
procedure in this section.
REPAIR as necessary.
z Damaged or worn
powertrain/drivetrain
mounts. z
CHECK the
powertrain/drivetrain
mounts for damage.
REPAIR as necessary.
z Engine or
transmission
grounded to chassis. z
INSPECT the
powertrain/drivetrain for
correct clearances.
REPAIR as necessary.
z Engine
vibration—
vibration felt at all
times z
Excessive engine
pulley runout. z
CARRY OUT Engine
Accessory Test. INSTALL a
new engine pulley as
necessary. REFER to
Section 303 - 01A for 3.8L
engines or Section 303 - 01B
for 4.6L (2V) engines.
z Damaged or worn
accessory
component. z
CARRY OUT Engine
Accessory Test. REPAIR or
INSTALL a new component Klj . 27 ba
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as necessary.
z Accelerator pedal
vibration— felt
through the pedal
as a buzz z
Throttle cable loose
or misrouted. z
INSPECT the throttle cable.
REPAIR as necessary.
REFER to Section 310 - 02 .
z Engine
vibration— mostly
at coast/neutral
coast. Condition
improves with
vehicle
accelerating z
Combustion
instability. z
CHECK the ignition system.
INSTALL new components
as necessary.
z Engine vibration
or shudder—
occurs with light
to medium
acceleration
above 56 km/h
(35 mph) z
Worn or damaged
spark plugs. z
INSPECT the spark plugs
for cracks, high resistance
or broken insulator.
INSTALL a new spark plug
(s) as necessary.
z Plugged fuel injector. zREPAIR or INSTALL a new
injector as necessary.
REFER to Section 303 - 04A
for 3.8L engines or
Section 303 - 04B for 4.6L (2V)
engines.
z Damaged spark plug
wire. z
INSPECT the spark plug
wires for damage. INSTALL
a new spark plug wire(s) as
necessary.
z Contaminated fuel. zINSPECT the fuel for
contamination. DRAIN the
fuel system and refill.
z Worn or damaged
torque converter. z
CHECK the torque
converter. INSTALL a new
torque converter as
necessary. REFER to
Section 307 - 01 .
Symptom Chart—
Idle Noise/Vibration Condition
Possible Sources Action
z Idle air control (IAC)
valve moan — occurs
on throttle tip- out z
IAC valve is
contaminated
with oil. z
GO to Component Tests in
this section.
z Accessory drive belt
chirp — occurs at idle
or high idle, cold or
hot. Most common
occurrence is during
humid weather z
Accessory drive
belt worn, or
pulley is
misaligned or
loose. z
INSPECT for loose or
misaligned pulleys. CHECK
the drive belt for wear or
damage. INSTALL new
pulley(s)/drive belt, or
accessory drive components
as necessary. REFER to
Section 303 - 05 .
z Accessory drive
bearing hoot —
occurs at idle or high
idle in cold
temperatures of
approximately +4°C z
Accessory drive
idler or
tensioner pulley
bearing is
experiencing
stick/slip z
Go To Pinpoint Test C . Klj . 28 ba
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REFILL as necessary.
z Power steering pump
brackets loose or
misaligned. z
CHECK bolts, brackets
and bracket alignment.
TIGHTEN bolts to
specification. REPAIR
or INSTALL new
brackets as necessary.
REFER to Section 211 -
02 .
z Steering gear clunk
— occurs only
while cornering
over a bump (can
be temperature
sensitive) z
Steering gear. zINSPECT the steering
gear for loose mounting
bolts. TIGHTEN as
necessary. REFER to
Section 211 - 02 .
z Feedback (rattle,
chuckle or
knocking noise in
the steering gear)
— a condition
where roughness is
felt in the steering
wheel when the
vehicle is driven
over rough
surfaces z
Column
intermediate/flexible
shaft joints damaged or
worn. z
INSTALL a new
intermediate/flexible
shaft. REFER to Section 211 - 04 .
z Loose, damaged or
worn tie- rod ends. z
TIGHTEN the nuts to
specification or
INSTALL new tie- rod
ends as necessary.
REFER to Section 211 -
02 .
z Steering gear
insulators or mounting
bolts loose or
damaged. z
TIGHTEN the bolts or
INSTALL new bolts as
necessary. REFER to
Section 211 - 02 .
z Steering column
intermediate shaft bolts
are loose. z
TIGHTEN the bolts to
specification. REFER to
Section 211 - 04 .
z Steering column
damaged or worn. z
REPAIR or INSTALL a
new steering column as
necessary. REFER to
Section 211 - 04 .
z Loose suspension
bushings, bolts or ball
joints. z
INSPECT the
suspension system.
TIGHTEN or INSTALL
new components as
necessary. REFER to
Section 204 - 01 .
z Feedback (nibble
at the steering
wheel) — a
condition where
slight rotational
movement is felt in
the steering wheel
when the vehicle is
driven over rough
or grooved z
Lateral runout in the
tire or wheel. z
GO to Pinpoint Test H . Klj . 34 ba
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Section 308 - 02 .
z Grease or oil on the
clutch disc facing. z
CHECK the input shaft
seal and rear main oil
seal. REPAIR as
necessary. INSTALL a
new clutch disc.
REFER to Section 308 -
03A for T50D
transmissions or
Section 308 - 03B for
TR3650 transmissions.
z Clutch disc surface
glazed or damaged. z
INSPECT the clutch
disc surface for a
glazed, hardened or
damage condition.
CARRY OUT a disc
check. INSTALL a new
clutch disc as
necessary. REFER to
Section 308 - 01 .
z Damaged or worn
clutch pressure
plate. z
INSPECT the clutch
pressure plate for wear
or damage. INSTALL a
new clutch pressure
plate as necessary.
REFER to Section 308 -
01 .
z Flywheel surface
damaged or glazed. z
INSPECT the flywheel
for damage or wear.
CARRY OUT a
flywheel runout check.
INSTALL a new
flywheel as necessary.
REFER to Section 303 -
01A for 3.8L engines or
Section 303 - 01B for
4.6L (2V) engines.
z Clutch chatter noise—
noise when clutch
pedal is released at
initial take- off. Clutch is
hard to engage and
disengage z
Pilot bearing worn,
damaged or not
correctly aligned in
bore. z
INSPECT the clutch
pressure plate release
fingers for uneven
wear, clutch
components burnt or a
seized pilot bearing.
INSTALL a new pilot
bearing as necessary.
REFER to Section 308 -
01 .
z Clutch vibration zLoose flywheel
bolts.
z Damaged or loose
clutch pressure
plate.
z Excessive flywheel
runout. z
Go To Pinpoint Test L .
z Transmission
rattling/clattering
noise— noise at idle or
on light acceleration
from a stop. Gear
selection difficult z
Gearshift lever joint
worn or damaged. z
INSTALL a new
gearshift lever. REFER
to Section 308 - 03A for
T50D transmissions or
Section 308 - 03B for
TR3650 transmissions. Klj . 41 ba
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flange runout.
Symptom Chart—
Transmission (Automatic) Noise/Vibration Condition
Possible Sources Action
z Rattle— occurs
at idle or at
light
acceleration
from a stop z
Damaged engine or
transmission mounts. z
CHECK the
powertrain/drivetrain mounts
for damage. REPAIR or
INSTALL new mounts as
necessary.
z A loose front exhaust
pipe heat shield. z
REPAIR or INSTALL a new
heat shield as necessary.
z Loose inspection
plate or dust cover
plate. z
CHECK for loose bolts.
TIGHTEN to specifications.
REFER to Section 307 - 01 .
z Loose flex plate to
converter nuts. z
CHECK for loose nuts.
TIGHTEN to specifications.
REFER to Section 307 - 01 .
z Whine— pitch
increases with
vehicle speed.
Starts in first
and second
gear,
decreases or
goes away at
higher gears z
Damaged or worn low
one- way clutch.
z Damaged or worn
intermediate one- way
clutch.
z Friction elements.
z Damaged or worn
planetary or sun gear. z
INSPECT the transmission
for wear or damage. REPAIR
or INSTALL new components
as necessary. REFER to
Section 307 - 01 .
z Whine— the
pitch changes
with engine
speed z
A worn or damaged
accessory drive
component. z
CARRY OUT the Engine
Accessory Test. REPAIR or
INSTALL new components as
necessary.
z Incorrect fluid level. zCHECK that the transmission
is filled to the correct level.
ADD fluid as necessary.
REFER to Section 307 - 01 .
z Partially blocked filter. zINSPECT the filter. CLEAN or
INSTALL a new filter as
necessary. REFER to Section 307 - 01 .
z Worn or damaged
torque converter. z
CARRY OUT the torque
converter service and
replacement check. REFER
to Section 307 - 01 .
z Worn or damaged
front pump. z
INSPECT the front pump.
INSTALL a new front pump
as necessary. REFER to
Section 307 - 01 .
z Whine— pitch
changes with
vehicle speed z
Speedometer cable
or gears. z
REPAIR or INSTALL new
cables or gears as necessary.
z Whine/moan
type noise—
pitch increases
or changes
with vehicle
speed z
Damaged engine or
transmission mount. z
CHECK the
powertrain/drivetrain mounts
for damage. CARRY OUT
Powertrain/Drivetrain Mount Neutralizing in this section.
z U-joints worn or zINSPECT the U- joints for Klj . 45 ba
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Pinpoint Tests
The pinpoint tests are a step-by-
step diagnostic process designed to determine the cause of a z
Bump—occurs
when shifting
from PARK to
a drive or
reverse
position.
Similar to
Clunk but with
no sound z
Initial gear
engagement. z
Acceptable condition.
z Buzz or hiss zIncorrect driveline
angles. z
CHECK for correct driveline
angles. REPAIR as
necessary. REFER to Section 205 - 00 .
z Worn or damaged
main control
solenoids or valves. z
Using a transmission tester,
ACTIVATE the solenoids to
duplicate sound. INSTALL
new components as
necessary. REFER to Section 307 - 01 .
z Vibration— a
high frequency
(20–80 Hz) that
is felt through
the seat or
gear shifter.
Changes with
engine speed z
Transmission cooler
lines grounded out. z
CHECK the transmission
cooler lines. REPAIR as
necessary.
z Flexplate to torque
converter nuts loose. z
CHECK the flexplate nuts.
TIGHTEN to specification.
REFER to Section 307 - 01 .
z Fluid filler tube
grounded out. z
CHECK the fluid filler tube.
REPAIR as necessary.
z Shift cable incorrectly
routed, grounded out
or loose. z
CHECK the shift cable.
REPAIR as necessary.
Section 307 - 05 .
z Shutter or
chatter—
occurs with
light to medium
acceleration
from low
speeds or a
stop z
Electrical
inputs/outputs.
z Vehicle wiring
harness.
z Incorrect
inputs/outputs from
the powertrain control
module (PCM), digital
transmission range
(TR) sensor, brake
pedal position (BPP)
sensor, throttle
position (TP) sensor,
transmission speed
sensor (TSS), output
speed shaft (OSS)
sensor or the torque
converter clutch
(TCC). z
CARRY OUT a Torque
Converter Clutch Operation
Test. RUN on- board
diagnostics or self- test.
REFER to Section 307 - 01 .
CLEAR the DTC's, ROAD
TEST and RERUN on- board
diagnostics or self- test. Klj . 47 ba
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condition. It may not always be necessary to follow a pinpoint test to its conclusion. Carry out only the
steps necessary to correct the condition. Then, test the system for normal operation. Sometimes, it is
necessary to remove various vehicle components to gain access to the component requiring testing.
Reinstall all components after verifying system operation is normal.
PINPOINT TEST A: BRAKE VIBRATION/SHUDDER
Test Step Result / Action to Take
A1 ROAD TEST THE VEHICLE—
LIGHT BRAKING z
Check that the wheel and tires are correct for the vehicle.
Inspect the tires for abnormal wear patterns.
z Road test the vehicle. Warm the brakes by slowing the vehicle
a few times from 80– 32 km/h (50 to 20 mph) using light braking
applications. At highway speeds of 89–97 km/h (55- 60 mph),
apply the brake using a light pedal force.
z Is there a vibration/shudder felt in the steering wheel, seat
or brake pedal? Yes
GO to
A4 .
No
GO to A2 .
A2 ROAD TEST THE VEHICLE—
MODERATE TO HEAVY
BRAKING z
Road test the vehicle. At highway speeds of 89–97 km/h (55- 60
mph), apply the brake using a moderate to heavy pedal force.
z Is there a vibration/shudder? Yes
For vehicles with ABS,
GO to
A3 . For vehicles
with standard brakes,
GO to A4 .
No
Vehicle is OK. VERIFY
condition with customer.
TEST the vehicle for
normal operation. A3 NORMAL ACTUATION OF THE ABS SYSTEM DIAGNOSIS
z
During moderate to heavy braking, noise from the hydraulic
control unit (HCU) and pulsation in the brake pedal can be
observed. Pedal pulsation coupled with noise during heavy
braking or on loose gravel, bumps, wet or snowy surfaces is
acceptable and indicates correct functioning of the ABS
system. Pedal pulsation or steering wheel nibble, (frequency is
proportioned to the vehicle speed) indicates a concern with a
brake or suspension component.
z Is the vibration/shudder vehicle speed sensitive? Yes
GO to
A5 .
No
The brake system is
operating correctly. A4 APPLICATION OF THE PARKING BRAKE
z
NOTE: Begin at the front of the vehicle unless the vibration or
shudder has been isolated to the rear.
z This test is not applicable to vehicles with drum- in-hat type
parking brakes. For vehicles with drum- in-hat parking brakes,
proceed to the next test. For all other vehicles, apply the
parking brake to identify if the problem is in the front or rear
brake. At highway speeds of 89–97 km/h (55- 60 mph), lightly
apply the parking brake until the vehicle slows down. Release
the parking brake immediately after the test.
z Is there a vibration/shudder? Yes
GO to
A7 .
No
GO to A5 .
A5 CHECK THE FRONT WHEEL BEARINGS
z
Check the front wheel bearings. Refer to Wheel Bearing Check in this section.
z Are the wheel bearings OK? Yes
GO to
A6 . Klj . 48 ba
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4. While the noise is occurring, either place an EngineEAR probe near the IAC valve and the inlet
tube, or create a 6.35 mm (0.25 in)- 12.7 mm (0.50 in) air gap between the inlet tube and the
clean air tube. If the IAC valve is making the noise, install a new IAC valve.
5. Test the vehicle for normal operation.
Steering Gear Grunt/Shudder Test
1. Start and run the vehicle to operating temperature.
2. Set engine idle speed to 1200 rpm.
3. CAUTION: Do not hold the steering wheel against the stops for more than three to
five seconds at a time. Damage to the power steering pump will occur.
Rotate the steering wheel to the RH stop, then turn the steering wheel 90° back from that
position. Turn the steering wheel slowly in a 15° to 30° arc.
4. Turn the steering wheel another 90°. Turn the steering wheel slowly in a 15° to 30° arc.
5. Repeat the test with power steering fluid at different temperatures.
6. If a light grunt is heard or a low (50- 200 Hz) shudder is present, this is a normal steering system
condition.
7. If a loud grunt is heard, or a strong shudder is felt, fill and purge the power steering system.
Checking Tooth Contact Pattern and Condition of the Ring and Pinion
There are two basic types of conditions that will produce ring and pinion noise. The first type is a howl
or chuckle produced by broken, cracked, chipped, scored or forcibly damaged gear teeth and is
usually quite audible over the entire speed range. The second type of ring and pinion noise pertains to
the mesh pattern of the gear pattern. This gear noise can be recognized as it produces a cycling pitch
or whine. Ring and pinion noise tends to peak in a narrow speed range or ranges, and will tend to
remain constant in pitch.
1. Raise and support the vehicle. For additional information, refer to Section 100 - 02 .
2. Drain the axle lubricant. Refer to Section 205 - 02A for Ford 7.5 rear axles or
Section 205 - 02B for
Ford 8.8 integral axles.
3. Remove the carrier assembly or the axle housing cover depending on the axle type. Refer to Section 205 - 02A for Ford 7.5 rear axles or
Section 205 - 02B for Ford 8.8 integral axles.
4. Inspect the gear set for scoring or damage. Klj . 64 ba
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