To carry out this procedure, proceed as follows:

• Test preparations include matching customer conditions (if known). If not known, document the test conditions: gear selection and engine rpm. Monitor the vibration/noise duration with a watch for up to three minutes .
• Park the vehicle where testing will occur. The vehicle must remain at or below the concern temperature (if known) for 6-8 hours .
• Before starting the engine, conduct a visual inspection under the hood.
• Turn the key on, but do not start the engine. Listen for the fuel pump, Anti-lock Brake System (ABS) and air suspension system noises.
• Start the engine.
• Isolate the vibration/noise by carefully listening. Move around the vehicle while listening to find the general location of the vibration/noise. Then, search for a more precise location by using a stethoscope or EngineEAR.

CAUTION : Never probe moving parts.

• Refer to Idle Noise/Vibration in the Symptom Chart to assist with the diagnosis. See: Noise, Vibration, and Harshness Diagnosis\Symptom Charts\Idle Noise/Vibration