Locate The Noise And Identify The Root Cause

WARNING: This page is about a different car, the 2007 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.

Narrow down the noise to a general area. To help pinpoint the source of the noise, use a listening tool (Chassis Ear: J-39570, Engine Ear: J-39565 and mechanic's stethoscope).
Narrow down the noise to a more specific area and identify the cause of the noise by:

removing the components in the area that you suspect the noise is coming from.
Do not use too much force when removing clips and fasteners, otherwise clips and fasteners can be broken or lost during the repair, resulting in the creation of new noise.
tapping or pushing/pulling the component that you suspect is causing the noise.
Do not tap or push/pull the component with excessive force, otherwise the noise will be eliminated only temporarily.
feeling for a vibration with your hand by touching the component(s) that you suspect is (are) causing the noise.
placing a piece of paper between components that you suspect are causing the noise.
looking for loose components and contact marks.

Refer to "GENERIC SQUEAK AND RATTLE TROUBLESHOOTING ".