light FORD MUSTANG 2003 User Guide

A rhythmic tap, similar to a clock noise.
Tip-
In Moan
A light moaning noise heard during light vehicle acceleration, usually between 40- 100 km/h (25-65
mph).
TIR
The acronym for total indicated runout is TIR.
Tire Deflection
The change in tire diameter in the area where the tire contacts the ground.
Tire Flat Spots
A condition commonly caused by letting the vehicle stand while the tires cool off. This condition can be
corrected by driving the vehicle until the tires are warm. Also, irregular tire wear patterns in the tire
tread resulting from wheel- locked skids.
Tire Force Vibration
A tire vibration caused by variations in the construction of the tire that is noticeable when the tire
rotates against the pavement. This condition can be present on perfectly round tires because of
variations in the inner tire construction. This condition can occur at wheel rotation frequency or twice
rotation frequency.
Transient
A noise or vibration that is momentary, a short duration.
Two- Plane Balance
Radial and lateral balance.
Vibration
Any motion, shaking or trembling, that can be felt or seen when an object moves back and forth or up
and down.
Whine
A constant, high- pitched noise. Also described as a screech.
Whistle
High- pitched noise (above 500 Hz) with a very narrow frequency band. Examples of whistle noises are
a turbocharger or airflow around an antenna.
Wind Noise
Any noise caused by air movement in, out or around the vehicle. Klj . 10 ba
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Neutral Coast Down Speed Test
To carry out this test, proceed as follows:
zDrive at a higher rate of speed than where the concern occurred when carrying out the Slow
Acceleration Test.
z Place the transmission in NEUTRAL and coast down past the speed where the concern occurs.
z The concern is vehicle speed- related if duplicated while carrying out this test. This eliminates
the engine and the torque converter as sources.
z If the concern was not duplicated while carrying out this test, carry out the Downshift Speed
Test to verify if the concern is engine speed related.
z Proceed as necessary.
Downshift Speed Test
To carry out this test, proceed as follows:
zShift into a lower gear than the gear used when carrying out the Slow Acceleration Test.
z Drive at the engine rpm where the concern occurs.
z The concern is engine speed related if duplicated while carrying out this test. This eliminates the
tires, wheels, brakes and the suspension components as sources.
z If necessary, repeat this test using other gears and NEUTRAL to verify the results.
z Proceed as necessary.
Steering Input Test
To carry out this test, proceed as follows:
zDrive at the speed where the concern occurs, while making sweeping turns in both directions.
z If the concern goes away or gets worse, the wheel bearings, hubs, U- joints (contained in the
axles of 4WD applications), and tire tread wear are all possible sources.
z Proceed as necessary.
Brake Test
To carry out this test, proceed as follows:
zWarm the brakes by slowing the vehicle a few times from 80–32 km/h (50–20 mph) using light
braking applications. At highway speeds of 89–97 km/h (50– 60 mph), apply the brake using a
light pedal force.
z Accelerate to 89–97 km/h (55–60 mph).
z Lightly apply the brakes and slow the vehicle to 30 km/h (20 mph).
z A brake vibration noise can be felt in the steering wheel, seat or brake pedal. A brake noise can
be heard upon brake application and diminish when the brake is released.
Road Test Over Bumps
To carry out this test, proceed as follows: Klj . 7 ba
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„
Loudness proportional to vehicle speed. Low- frequency noise at high
speeds, noise and loudness increase with speed. GO to Symptom Chart —
Driveline Noise/Vibration .
„ A low- pitched noise (drumming). GO to Symptom Chart — Engine
Noise/Vibration .
„ Vibration occurs at a particular speed (mph) regardless of acceleration or
deceleration. GO to Symptom Chart — Tire Noise/Vibration .
„ Noise varies with wind/vehicle speed and direction. GO to Symptom Chart — Air Leak and Wind Noise .
„ Related to engine speed.
„Noise varies with engine rpm. GO to Symptom Chart — Engine
Noise/Vibration .
„ Vibration occurs at a particular speed (mph) regardless of engine speed
(rpm).
2. Acceleration
„Wide open throttle (WOT)
„Engine induced contact between components. Inspect and repair as
necessary.
„ Noise is continuous throughout WOT. Exhaust system or engine ground
out. GO to Symptom Chart — Engine Noise/Vibration .
„ Light/moderate acceleration
„Tip- in moan. Engine/exhaust noise. GO to Symptom Chart — Engine
Noise/Vibration .
„ Knock-type noise. GO to Symptom Chart — Engine Noise/Vibration .
„ Driveline shudder. GO to Symptom Chart — Driveline Noise/Vibration .
„ Engine vibration. GO to Symptom Chart — Engine Noise/Vibration .
3. Turning noise. GO to Symptom Chart — Steering Noise/Vibration .
4. Braking
„Clicking sound is signaling ABS is active. Acceptable ABS sound.
„ A continuous grinding/squeal. GO to Symptom Chart — Brake Noise/Vibration .
„ Brake vibration/shudder. GO to Symptom Chart — Brake Noise/Vibration .
5. Clutching
„A noise occurring during clutch operation. GO to Symptom Chart — Transmission
(Manual) and Transfer Case Noise/Vibration .
„ Vibration. GO to Symptom Chart — Transmission (Manual) and Transfer Case
Noise/Vibration .
6. Shifting
„Noise or vibration condition related to the transmission (automatic). GO to
Symptom Chart — Transmission (Automatic) Noise/Vibration .
„ Noise or vibration related to the transmission (manual). GO to Symptom Chart —
Transmission (Manual) and Transfer Case Noise/Vibration .
7. Engaged in four- wheel drive. GO to Symptom Chart — Transmission (Manual) and
Transfer Case Noise/Vibration .
8. Cruising speeds
„Accelerator pedal vibration. GO to Symptom Chart — Engine Noise/Vibration .
„ Driveline vibration. GO to Symptom Chart — Driveline Noise/Vibration .
„ A shimmy or shake. GO to Symptom Chart — Tire Noise/Vibration .
9. Driving at low/medium speeds Klj . 11 ba
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occurs on first
(morning) brake
application
pads.
Caused by humidity and
low disc brake pad
temperature.
z Squealing noise— a
continuous squeal z
Disc brake pads
or linings worn
below minimum
thickness. z
INSTALL new disc brake
pads. REFER to Section 206 - 03 for front disc brake
pads or Section 206 - 04 for
rear disc brake pads.
z Squealing noise— an
intermittent squeal
brought on by cold,
heat, water, mud or
snow z
Disc brake pad. zAcceptable condition.
z Groaning noise—
occurs at low speeds
with brake lightly
applied (creeping) z
Disc brake
pads. z
Acceptable condition.
z Grinding noise—
continuous z
Disc brake pads
or linings worn
below minimum
thickness. z
INSPECT the disc brake
pads, brake discs and
attaching hardware for
damage. REPAIR or
INSTALL new components
as necessary. REFER to
Section 206 - 03 for front
disc brakes and Section 206 - 04 for rear disc brakes.
z Moaning noise zBrake linings
contaminated
with grease or
oil. z
INSPECT the brake pads
and shoes for
contamination. REPAIR or
INSTALL new components
as necessary. REFER to
Section 206 - 03 for front
disc brakes or Section 206 -
04 for rear disc brakes.
z Brake
vibration/shudder—
occurs when brakes
are applied z
Uneven disc or
drum wear.
z Uneven disc
brake pad or
lining transfer.
z Suspension
components. z
Go To Pinpoint Test A .
z Brake
vibration/shudder—
occurs when the brake
pedal is released z
Brake drag. zINSPECT the disc brake
pads or linings for
premature wear. REPAIR
or INSTALL a new caliper
or wheel cylinder as
necessary. REFER to
Section 206 - 03 for front
disc brakes and Section 206 - 04 for rear disc brakes.
Symptom Chart—
Driveline Noise/Vibration Condition
Possible Sources Action
z Axle howling or
whine— front or rear
axle z
Axle lubricant
low. z
CHECK the lubricant level.
FILL the axle to
specification.
z Axle housing zINSPECT the axle housing Klj . 17 ba
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noise—
normally
accompanied by
vibration Powertrain/Drivetrain Mount Neutralizing in this
section.
z Damaged or
misaligned exhaust
system. z
INSPECT the exhaust
system for loose or broken
clamps and brackets.
CARRY OUT Exhaust System Neutralizing in this
section.
z Whistling noise—
normally
accompanied
with poor idle
condition z
Air intake system. zCHECK the air intake
ducts, air cleaner, throttle
body and vacuum hoses for
leaks and correct fit.
REPAIR or ADJUST as
necessary. REFER to
Section 303 - 12
z
Clunking noise zWater pump has
excessive end play or
imbalance. z
CHECK the water pump for
excessive end play.
INSPECT the water pump
with the drive belt off for
imbalance. INSTALL a new
water pump as necessary.
REFER to Section 303 -
03A .
z Generator has
excessive end play. z
CHECK the generator for
excessive end play.
REPAIR or INSTALL a new
generator. REFER to
Section 414 - 02 .
z Pinging noise zExhaust system leak. zINSPECT the exhaust
system for leaks. REPAIR
as necessary.
z Gasoline octane too
low. z
VERIFY with customer the
type of gasoline used.
CORRECT as necessary.
z Knock sensor
operation. z
CHECK the knock sensor.
INSTALL a new knock
sensor as necessary.
REFER to Section 303 - 14 .
z Incorrect spark
timing. z
CHECK the spark timing.
REPAIR as necessary.
z High operating
temperature. z
INSPECT cooling system
for leaks. CHECK the
coolant level. REFILL as
necessary. CHECK the
coolant for the correct mix
ratio. DRAIN and REFILL
as needed. CHECK engine
operating temperature is
within specifications.
REPAIR as necessary.
z Foul- out spark plug. zCHECK the spark plugs.
REPAIR or INSTALL new
spark plugs as necessary.
z Catalytic converter. zAcceptable noise.
z Knocking noise—
light knocking
noise, also z
Excessive clearance
between the piston
and the cylinder wall. z
Engine cold and at high
idle. Using an EngineEAR,
pull a spark plug or fuel Klj . 24 ba
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described as
piston slap. Noise
is most
noticeable when
engine is cold
with light to
medium
acceleration.
Noise disappears
as engine warms
injector connector until the
noise goes away. CARRY
OUT a cylinder bore
clearance to piston check.
INSTALL a new piston.
REFER to
Section 303 - 01A
for 3.8L engines or
Section 303 - 01B for 4.6L (2V)
engines.
z Knocking noise—
light double
knock or sharp
rap sound.
Occurs mostly
with warm engine
at idle or low
speeds in DRIVE.
Increases in
relation to engine
load. Associated
with poor
lubrication history z
Excessive clearance
between the piston
and the piston pin. z
INSTALL a new piston or
piston pin. REFER to
Section 303 - 01A for 3.8L
engines or Section 303 - 01B
for 4.6L (2V) engines.
z Knocking noise—
light knocking
noise is most
noticeable when
engine is warm.
Noise tends to
decrease when
vehicle is
coasting or in
neutral z
Excessive clearance
between the
connecting rod
bearings and the
crankshaft. z
Engine warm and at idle.
Using an EngineEAR,
PULL a spark plug or fuel
injector connector until the
noise goes away. INSTALL
new bearings. REFER to
Section 303 - 01A for 3.8L
engines or Section 303 - 01B
for 4.6L (2V) engines.
z Knocking— deep
knocking noise.
Noise is most
noticeable when
engine is warm,
at lower rpm and
under a light load
and then at float z
Worn or damaged
crankshaft main
bearings. z
CARRY OUT DERU test.
CHECK for noise with
vehicle at operating
temperature, during
medium to heavy
acceleration. CHECK at
idle with injector
disconnected, noise does
not change. INSTALL new
main bearings. REFER to
Section 303 - 01A for 3.8L
engines or Section 303 - 01B
for 4.6L (2V) engines.
z Knocking noise—
occurs mostly
with warm engine
at light/medium
acceleration z
Spark plugs. zCHECK the spark plug for
damage or wear. INSTALL
new spark plugs as
necessary.
z Carbon accumulation
in combustion
chamber. z
REMOVE carbon from
combustion chamber.
z Whine or
moaning noise z
Air intake system. zCHECK the air cleaner and
ducts for correct fit.
INSPECT the air intake
system for leaks or
damage. REPAIR as
necessary. Klj . 25 ba
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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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