Steering System Noise Definitions: Moan
WARNING: This page is about a different car, the 2006 Ford Pickup, 2006 Ford F550 Super Duty, 2006 Ford F450 Super Duty, and 2006 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
Moan is the general structure-borne noise of the steering system. Moan is typically in the frequency range of 100 Hz to 600 Hz. Moan is primarily transmitted to the driver via body structure, through the pump mount, engine mounts, power steering lines and brackets. For problem vehicles, moan is a loud humming noise, often present when the wheel is turned and the system is loaded. It may change in frequency with RPM and if the system is loaded or unloaded.