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Test Description
The number(s) below refer to the steps) in the diagnostic table.
2:
This test is to verify that the vibration is present during diagnosing. Other vehicle components may
cause a similar symptom such as the exhaust system, or the drivetrain.
3:
This test is to verify that the drive belt(s) or accessory drive components may be causing the vibration.
Remove the drive belt(s) and operate the engine for a few seconds, this will verify if the vibration is
related to the drive belt(s) or not. With the drive belt(s) removed the water pump will not operate and the
engine may overheat. Also diagnostic trouble codes (DTCs) may set when the engine is operated with the
drive belt (s) removed.
4:
The drive belt(s) may cause a vibration. While the drive belt(s) is removed this is the best time to
inspect the condition of the drive belt(s).
6:
Inspection of the fasteners can eliminate the possibility that a incorrect bolt, nut, spacer, or washer was
installed.
8:
This step should only be performed if the fan is driven by the drive belt. Inspect the engine cooling fan
for bent, twisted, loose, or cracked blades. Inspect the fan clutch for smooth operation. Inspect for a bent
fan shaft or a bent mounting flange.
9:
Inspect the water pump drive shaft for being bent. Also inspect the water pump bearings for smooth
operation and excessive play. Compare the water pump with a known, good water pump.
10:
Accessory drive component brackets that are bent, cracked, or loose may put an extra strain on that
accessory component causing it to vibrate.
Drive Belt Vibration Diagnosis
Step
Action
Yes
No
DEFINITION: The following items are indications of drive belt vibration:
z
The vibration is engine-speed related.
z
The vibration may be sensitive to accessory load.
NOTE:
Refer to Belt Dressing Notice in Cautions and Notices.
1
Did you review the Symptoms - Engine
Mechanical diagnostic information, and perform
the necessary inspections?
Go to
Step 2
Go to
Symptoms -
Engine
Mechanical
2
Verify that the vibration is engine related.
Does the engine make the vibration?
Go to
Step 3
Go to Diagnostic
Aids
3
1. Remove the drive belt (s). Refer to
Drive
Belt Replacement - Accessory
or
Drive
Belt Replacement - Air Conditioning
.
2. Operate the engine for no longer than 30 to
40 seconds.
Go to
Vibration Analysis
- Engine
in Vibration
2004 Chevrolet Corvette
2004 ENGINE PERFORMANCE Engine Mechanical (Introduction) - 5.7L - Corvette
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December-24-07 10:50:10 AM
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