2002 QX4 vibration

[Israelpr]

There is a vibration I believe is on the passenger side between the seat and the engine. It's not a "rattling" sound like heat shields, but more like a "vibration" involving "metal and rubber". It happens when I acelarate and decelarate only. It does not happen during steady driving. Nothing vibrates in the QX4 (steering wheel is fine and it's properly aligned) but there "a vibrating sound". Any ideas what this may be or how I can identify the problem? Thanks.

[Towncivilian]

Are your wheels properly balanced? Are the tire pressures all within specification? Any worn suspension bushings or components on the passenger side (check sway bar links, tie rod ends, etc)? Check out the motor mounts too.