Ford Falcon. Manual — part 13

100-04-24

Noise, Vibration and Harshness

100-04-24

DIAGNOSIS AND TESTING (Continued)

Condition

Source

Action

Excessive runout of valve seats on the

CARRY OUT a valve seat runout test.

INSPECT the valve face and seat.

valve face.

INSTALL new valves as necessary.
REFER to Section 303.

Rattling noise—from the bottom of the

Loose muffler shields or catalytic

CHECK the exhaust system for loose

vehicle

converter shields.

shields. REPAIR as necessary.

Thumping noise—from the bottom of

Exhaust pipe/muffler grounded to

CHECK the exhaust system to chassis

clearance. CHECK the exhaust system

the vehicle, worse at acceleration

chassis.

hangers for damage. REPAIR as
necessary.

Engine vibration—increases intensity

CARRY OUT Neutral Engine Run-up

Engine out-of-balance.

(NERU) Test. ROTATE the torque

as engine rpm is increased

converter, 120

° for 3 bolt and 180° for

4 bolt. INSPECT the torque converter
pilot outer diameter to crankshaft pilot
inner diameter.

Engine vibration—is felt with increases

CARRY OUT the Exhaust System

Strain on exhaust mounts.

Neutralizing procedure in this section.

and decreases in engine rpm

REPAIR as necessary.

Damaged or worn powertrain/drivetrain

CHECK the powertrain/drivetrain

mounts for damage. REPAIR as

mounts.

necessary.

Engine or transmission grounded to

INSPECT the powertrain/drivetrain for

correct clearances. REPAIR as

chassis.

necessary.

Engine vibration—vibration felt at all

CARRY OUT Engine Accessory Test.

Excessive engine pulley runout.

INSTALL a new engine pulley as

times

necessary. REFER to Section 303.

Damaged or worn accessory

CARRY OUT Engine Accessory Test.

REPAIR or INSTALL a new

component.

component as necessary. REFER to
Section 303-05.

Engine vibration—mostly at

CHECK the ignition system. INSTALL

Combustion instability.

coast/neutral coast—condition

new components as necessary.

improves with vehicle accelerating

Engine vibration or shudder—occurs

INSPECT the spark plugs for cracks,

Worn or damaged spark plugs.

with light to medium acceleration

high resistance or broken insulator.
INSTALL a new spark plug(s) as

above 56 km/h (35 mph)

necessary.

REPAIR or INSTALL a new injector as

Plugged fuel injector.

necessary.

INSPECT the spark plug wires for

Damaged spark plug wire.

damage. INSTALL a new spark plug
wire(s) as necessary.

INSPECT the fuel for contamination.

Contaminated fuel.

DRAIN the fuel system and refill.

CHECK the torque converter. INSTALL

Worn or damaged torque converter.

a new torque converter as necessary.
REFER to Section 307-01 .

Symptom Chart—Idle Noise/Vibration

Condition

Source

Action

Idle air control (IAC) valve moan —

GO to Component Tests in this

IAC valve is contaminated with oil.

occurs on throttle tip-out

section.

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100-04-25

Noise, Vibration and Harshness

100-04-25

DIAGNOSIS AND TESTING (Continued)

Condition

Source

Action

Accessory drive belt chirp — occurs at

Accessory drive belt worn, or pulley is

INSPECT for loose or misaligned

idle or high idle, cold or hot—most

pulleys. CHECK the drive belt for wear

misaligned or loose.

common occurrence is during humid

or damage. INSTALL new pulley(s) or
accessory drive belt, as necessary.

weather

REFER to Section 303-05 .

Accessory drive bearing hoot —

Accessory drive idler or tensioner

Go to PinPoint Test C .

occurs at idle or high idle in cold

pulley bearing is experiencing stick/slip

temperatures of approximately +4

°C

between ball bearings and bearing

(+40

°F) or colder at first start of the

race.

day

Power steering moan — occurs at high

High fluid viscosity, or plugged

Go to PinPoint Test D .

idle and possibly at idle during the first

reservoir screen in power steering

cold start of the day in temperatures of

reservoir starves pump causing

approximately -18

°C (0°F) or

cavitation.

colder—noise can even be a severe
screech for less than one minute in
very cold temperatures of
approximately -29

°C (-20°F) or colder

Alternator whine — during high

CHECK for changes in the noise level

Alternator electrical field noise.

electrical loads at idle or high idle, a

while changing electrical loads (such

high pitch whine or moan is emitted

as rear defrost, headlamps etc.).
CARRY OUT a alternator load test.

from the alternator

REFER to Section 414-00 . If the
system passes the load test, the noise
is from the alternator bearings,
INSTALL new bearings. If the system
fails the load test, INSTALL a new
alternator. REFER to Section 414-02 .

Drumming noise — occurs inside the

Exhaust system vibration excites the

Go to PinPoint Test E .

vehicle during idle or high idle, hot or

body resonances inducing interior

cold—very low-frequency drumming is

noise.
Engine vibration excites the body

very rpm dependent

resonances inducing interior noise.

Hissing noise — occurs during idle or

Vacuum leak or idle air control (IAC)

CHECK the air intake system from the

high idle that is apparent with the hood

inlet to each cylinder intake port.

valve flow noise.

DISCARD the leaking parts, and

open

INSTALL a new component.

CHECK for correct driveline angles.

Automatic transmission buzz or hiss

Incorrect driveline angles.

REPAIR as necessary. REFER to
Section 205-00 .

Worn or damaged main control

Using a transmission tester,

ACTIVATE the solenoids to duplicate

solenoids or valves.

sound. INSTALL new components as
necessary. REFER to Section 307-01 .

Manual Transmission Clutch throw-out

INSTALL a new throw-out bearing.

Worn throw-out bearing.

bearing whine—a change in noise

REFER to Section 308-01 .

pitch or loudness while depressing the
clutch pedal

Heating, vacuum and air conditioning

Damaged or worn HVAC blower

INSTALL a new blower motor. REFER

(HVAC) system chirp — most audible

bearing.

to Section 412-02 .

inside the vehicle—listen for a change
in noise pitch or loudness while
changing the HVAC system blower
speed

Air conditioning (A/C) clutch ticking —

Acceptable noise.

LISTEN to the clutch to determine if

occurs when the compressor clutch

the noise occurs with clutch

Incorrect air gap.

engagement. A small amount of noise

engages

is acceptable. If the noise is excessive,
CHECK the A/C clutch air gap.
INSPECT the A/C clutch for wear or
damage. INSTALL a new clutch as
necessary. REFER to Section 412-03 .

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100-04-26

Noise, Vibration and Harshness

100-04-26

DIAGNOSIS AND TESTING (Continued)

Condition

Source

Action

Intermittent rattle, or scraping/rubbing

INSPECT the exhaust system for

Loose exhaust heat shield(s).

loose parts using a glove or clamps to

noise

verify cause. REPAIR as necessary.
REFER to Section 309-00 .

Wiring, hose or other part interfering

INSPECT the accessory drive system

closely verifying there is adequate

with the accessory drive belt or pulley.

clearance to all rotating components.
REPAIR as necessary.

Engine ticking or knocking noise —

Piston noise or valvetrain noise (bled

Go to PinPoint Test F .

occurs during idle or high idle during

down lifter/lash adjuster).

the first cold start of the day

A continuous, speed-dependent rattle

Piston noise or valvetrain noise (bled

Go to PinPoint Test F .

from the engine — occurs during idle

down lifter/lash adjuster).

or high idle during the first cold start of
the day and disappears as the engine
warms up

Idle vibration—a low-frequency

Using the diagnostic tool, CHECK the

Cylinder misfire.

vibration (5-20 Hz) or mild shake that

ignition system. CARRY OUT a
cylinder power test. REFER to Section

is felt through the seat/floorpan

303-00 .

Engine or torque converter out of

VERIFY the torque converter to

crankshaft pilot clearance is correct,

balance.

REPAIR as necessary. RE-INDEX the
torque converter on the flex plate by
120

° on a 3-bolt converter or 180° for

a 4-bolt converter. REFER to Section
307-01 . RETEST the vehicle.

Idle vibration—a high-frequency

VERIFY concern occurs at engine

Exhaust system mounts bound up.

vibration (20–80 Hz) or buzz, that is

firing frequency. CHECK that the
exhaust system vibrates at the same

felt through the steering wheel or seat

frequency as the engine. ADD 9–14
km (20–30 lb.) to the tail pipe to test,
CARRY OUT Exhaust System
Neutralizing in this section.

INSPECT that the power steering lines

Power steering lines grounded out.

are not contacting the chassis or each
other. REPAIR as necessary.

NEUTRALIZE the powertrain/drivetrain

Engine mounts binding.

mounts. CARRY OUT
Powertrain/Drivetrain Mount
Neutralizing in this section.

Symptom Chart—Squeak and Rattle

Condition

Source

Action

Squeak—heard inside the vehicle

Insufficient lubrication on the door

LUBRICATE the hinge or check strap.

when closing/opening the door

hinge or check strap.

Internal door components loose,

CHECK the inside of the door.

TIGHTEN or ALIGN as necessary.

rubbing or misaligned.

USE the Rotunda Squeak and Rattle
Kit to ISOLATE any rubbing
components.

Squeak—heard inside the vehicle

REPAIR or INSTALL a new glass

Worn or damaged glass run/channel.

run/channel. REFER to Section 501-11

when closing/opening the window

.

Squeak—heard outside of vehicle

Exhaust shield rubbing against the

CHECK the exhaust system. REPAIR

as necessary. REFER to Section

when closing/opening the door

chassis or exhaust pipe.

309-00 .

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100-04-27

Noise, Vibration and Harshness

100-04-27

DIAGNOSIS AND TESTING (Continued)

Condition

Source

Action

Squeak—occurs with initial brake

Under certain conditions, asbestos free

Disc brake pads.

pads can generate a squeak noise.

pedal application

This noise is normal and does not
indicate a concern.

Squeak—a constant noise that occurs

INSPECT the pads for oil, grease or

Damaged or worn disc brake pads.

brake fluid contamination. CHECK for

with brake pedal applications

glazed linings. A brake disc with hard
spots will also cause a squeak type
noise. REPAIR or INSTALL new brake
pads as necessary. REFER to Section
206-03 .

Squeak—noise occurs over bumps or

INSPECT the control arm bushings.

Worn control arm bushings.

Spray with lubricant and CARRY OUT

when turning

a “bounce test” to determine which
bushing. REPAIR as necessary.
REFER to Section 204-01 for front
bushings or Section 204-02 for rear
bushings.

Worn or damaged shock

INSPECT the shock absorber for

damage. CARRY OUT a “bounce test”

absorber/strut.

to isolate the noise. INSTALL a new
shock absorber/strut as necessary.
REFER to Section 204-01 for front
shock absorber/strut or Section 204-02
for rear shock absorber/strut.

Rattle—heard when closing/opening

Loose internal door mechanism,

REPEAT the motion or CARRY OUT a

“tap test” to duplicate the noise.

the door or window

bracket or attachment.

INSPECT the door for loose
components. TIGHTEN loose
components.

Squeak or rattle—heard inside the

Misaligned glove compartment

ALIGN the glove compartment door.

vehicle over rough roads/bumps

door/hinge.

Instrument panel trim loose or

INSPECT the instrument panel trim for

missing or loose clips or screws.

misaligned.

REPAIR as necessary.

CARRY OUT a “touch test”.

Loose interior component or trim.

ELIMINATE the noise by pressing or
pulling on interior trim and
components.

Squeak or rattle—noise with a

INSPECT the upper and lower

Damaged or worn sub-frame mounts.

absorbers for damage or wear.

vibration concern

CHECK the sub-frame for damage.
CHECK the nuts and bolts are
tightened to specifications. TIGHTEN
as necessary.

Symptom Chart—Steering Noise/Vibration

Condition

Source

Action

Steering grunt or shudder — occurs

GO to Steering Gear Grunt/Shudder

Steering gear or power steering hoses.

when turning into or out of a turn at

Test component test in this section.

low speeds (temperature sensitive)

Steering System clonk—hydraulic

CHECK for leaks in the system.

Air in the steering hydraulic system.

PURGE the air from the system.

knocking sound

REFER to Section 211-00 .

Power steering pump moan — loud

Power steering hose grounded out to

INSPECT the power steering hoses.

humming noise occurs when the

chassis.

REPAIR as necessary.

steering wheel is rotated to the stop
position. Produces a 120-600 Hz
frequency that changes with rpm

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