Ford 2003 Mustang Workshop Manual page 99

Carry out the Vehicle Cold Soak Procedure
in this section.
Key in START position.
Assess the airflow.
Raise the engine speed to 1500 rpm while
listening for the moan to increase in
proportion to the airflow.
Key in OFF position.
Does the moan increase in proportion to
the airflow?
E2 CHECK THE ENGINE DRIVEN COOLING
FAN AT NORMAL OPERATING TEMPERATURE
Key in START position.
Run the engine to normal operating
temperature while listening for the moan to
stop.
Key in OFF position.
Does the moan stop?
PINPOINT TEST F: DRUMMING NOISE
F1 CHECK THE EXHAUST SYSTEM
Key in START position.
Increase the engine rpm until the noise is the loudest. Note
the engine rpm.
Key in OFF position.
Add approximately 9 kg (20 lb) of weight to the exhaust
system. First place the weight at the tail pipe and test, then
at the front pipe.
Key in START position.
Increase the engine rpm and listen for the drumming noise.
Note the engine rpm if the noise occurs.
Key in OFF position.
Using a vibration analyzer (VA), determine the amount of
vibration that occurs with the drumming noise.
Is the noise/vibration reduced or eliminated, or does the
noise/vibration occur at a different rpm?
F2 POWERTRAIN/DRIVETRAIN MOUNT NEUTRALIZING
Carry out Powertrain/Drivetrain Mount Neutralizing
section. Test the system for normal operation.
Is the noise reduced or eliminated?
Test Step
Yes
TEST the fan for normal operation. If the
fan tests normal, GO to
REPAIR as necessary.
No
Normal system operation.
Yes
Normal clutch operation.
No
INSTALL a new fan clutch. TEST the
system for normal operation.
Result / Action to Take
Yes
CARRY OUT
System Neutralizing
section. TEST the system
for normal operation.
No
GO to F2
Yes
in this
Vehicle OK. TEST the
system for normal
operation.
No
E2 . Otherwise,
Exhaust
in this
.