Ford Falcon. Manual - part 10
100-04-12
Noise, Vibration and Harshness
100-04-12
DIAGNOSIS AND TESTING (Continued)
engine rpm and, if possible, determine the
If the vibration/noise is duplicated when carrying
vibration frequency.
out this test, the belts and accessories are not
sources.
Attempt to identify what part of the vehicle the
concern is coming from.
If the vibration/noise was not duplicated when
carrying out this test, install each accessory belt,
Attempt to identify the source of the concern.
one at a time, to locate the source.
Proceed as necessary.
Vehicle Cold Soak Procedure
Drive Engine Run-Up (DERU) Load Test
To carry out this procedure, proceed as follows:
To carry out this test, proceed as follows:
Test preparations include matching customer
conditions (if known). If not known, document the
WARNING: Block the front and rear
test conditions: gear selection and engine rpm.
wheels, and apply the parking brake and the
Monitor the vibration/noise duration with a watch
service brake, or injury to personnel can
for up to three minutes.
result.
Park the vehicle where testing will occur. The
CAUTION: Do not carry out the Engine
vehicle must remain at or below the concern
Load Test for more than five seconds or
temperature (if known) for 6-8 hours.
damage to the transmission or transaxle can
Before starting the engine, conduct a visual
result.
inspection under the hood.
Block the front and rear wheels.
Turn the key on, but do not start the engine.
Apply the parking brake and the service brake.
Listen for the fuel pump, anti-lock brake system
Install a tachometer.
(ABS) and air suspension system noises.
Shift the transmission into DRIVE, and increase
Start the engine.
and decrease the engine rpm between an idle to
approximately 2,000 rpm. Note the engine rpm
CAUTION: Never probe moving parts.
and, if possible, determine the vibration
Isolate the vibration/noise by carefully listening.
frequency.
Move around the vehicle while listening to find the
general location of the vibration/noise. Then,
Repeat the test in REVERSE.
search for a more precise location by using a
If the vibration or noise is duplicated when
stethoscope or EngineEAR.
carrying out this test, inspect the engine and
Refer to Idle Noise/Vibration in the Symptom
transmission or transaxle mounts.
Chart to assist with the diagnosis.
If the concern is definitely engine speed-related,
carry out the Engine Accessory Test to narrow
6: Check OASIS/TSBs/Repair History
down the source.
After verifying the customer concern, check for OASIS
Proceed as necessary.
reports, TSBs and the vehicle repair history for related
Engine Accessory Test
concerns. If information relating to a diagnosis/repair
is found, carry out the procedure(s) specified in that
To carry out this test, proceed as follows:
information.
If no information is available from these sources, carry
WARNING: Block the front and rear
out the vehicle preliminary inspection to eliminate any
wheels, and apply the parking brake and the
obvious faults.
service brake, or injury to personnel can
result.
7: Diagnostic Procedure
CAUTION: Limit engine running time to
Qualifying the concern by the particular sensation
one minute or less with belts removed or
present can help narrow down the concern. Always
serious engine damage will result.
use the “symptom” to “system” to “component” to
NOTE: A serpentine drive belt decreases the
“cause” diagnosis technique. This diagnostic method
usefulness of this test. In these cases, use a
divides the problem into related areas to correct the
vibration analyzer, such as the EVA, to pinpoint
customer concern.
accessory vibrations. An electronic listening
Verify the “symptom”.
device, such as an EngineEAR, will also help to
Determine which “system(s)” can cause the
identify noises from specific accessories.
“symptom”.
Remove the accessory drive belts.
If a vibration concern is vehicle speed related,
Increase the engine rpm to where the concern
the tyre and wheel rpm/frequency or
occurs.
driveshaft frequency should be calculated.
G72679 en