Econoline E350 1 Ton V8-5.4L Prop SOHC VIN Z (1998)
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Verify the "symptom".
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Determine which "system(s)" can cause the "symptom".
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If a vibration concern is vehicle speed related. the tire and wheel rpm/frequency or driveshaft frequency should be calculated.
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If a vibration concern is engine speed related. the engine, engine accessory or engine firing frequencies should be calculated.
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After determining the "system", use the diagnostic tools to identify the worn or damaged 'components".
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After identifying the "components". try to find the "cause" of the failure.
Once the concern is narrowed down to a symptom/condition. proceed to NVH Condition and Symptom Categories.
Operating Condition - Vehicle Is Not Moving
1.
Static operation
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Noise occurs during part/system functioning.
GO to Symptom Chart - Squeak and Rattle.
2.
While cranking
1.
Grinding or whine, differential ring gear or starter motor pinion noise. GO to Symptom Chart - Engine Noise/Vibration.
2.
Rattle. Exhaust hanger, exhaust heat shield or A/C line noise. GO to Symptom Chart - Squeak and Rattle.
3.
Vibration. Acceptable condition.
3.
At idle
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Idle noise. GO to Symptom Chart - Idle
Noise/Vibration.
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Idle vibration or shake. GO to Symptom
Chart - Idle Noise/Vibration.
4.
During Gear Selection
1.
Vehicle parked on a steep incline. Acceptable
noise.
2.
Vehicle parked on a flat surface. GO to Symptom Chart - Driveline Noise/Vibration.
3.
Vehicle with a manual transmission. GO to Symptom Chart - Transmission (Manual) and Transfer Case Noise/Vibration.
Operating Condition - Vehicle Is Moving
1.
Depends more on how the vehicle is operated
1.
Speed related
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Related to vehicle speed
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Pitch increases with vehicle speed. GO
to Symptom Chart - Tire
Noise/Vibration.
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Noise occurs at specific vehicle speed.
A high-pitch noise (whine). GO to
Symptom Chart - Driveline
Noise/Vibration.
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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.
