Ford 2003 Mustang Workshop Manual page 73

Drone type noise
Sputter type
noise—noise
worse when cold,
lessens or
disappears when
vehicle is at
operating
temperature
Rattling noise—
noise from the
upper engine
(valve train).
Worse when
engine is cold
Generator electrical
field or bearings.
Exhaust system.
A/C compressor.
Powertrain mounts.
Damaged or worn
exhaust system
components.
Low oil level.
Thin or diluted oil.
Low oil pressure.
Worn rocker
arms/fulcrums or
followers.
Worn valve guides.
CARRY OUT generator
load test. REPAIR or
INSTALL a new generator
as necessary. REFER to
Section 414-02 .
CARRY OUT the Exhaust
System Neutralizing in this
section. REPAIR as
necessary.
CHECK for noise with
vehicle at constant speeds.
CYCLE the compressor on
and off and listen for a
change in pitch. REPAIR as
necessary. REFER to
Section 412-03 .
CARRY OUT the
Powertrain/Drivetrain
Mount Neutralizing in this
section.
INSPECT the exhaust
system for leaks or
damage. REPAIR as
necessary. REFER to
Section 309-00 .
CHECK oil level. FILL as
necessary.
INSPECT the oil for
contamination. If oil is
contaminated, CHECK for
the source. REPAIR as
necessary. CHANGE the oil
and filter.
CARRY OUT an oil
pressure test. If not within
specifications, REPAIR as
necessary. REFER to
Section 303-00 .
CARRY OUT a valve train
analysis. INSTALL new
valve train components as
necessary. REFER to
Section 303-01A for 3.8L
engines or Section 303-01B
for 4.6L (2V) engines.
CARRY OUT a valve train
analysis. INSTALL new
valve guides as necessary.
REFER to Section 303-01A
for 3.8L engines or Section
303-01B for 4.6L (2V)
engines.