Unfortunately my 2004 mini cooper s' power steering decided to go. Before it went it was making loud whining noises. Then, it just gave out as I came out of a turn.:confused:

Lots of info here which may help you:
Power Steering Pump replacement - Forums (http://forum.minicooper.org/showthread.php?t=9626)

unfortunately my friend , you are a victim of the very common power steering failure. Not much to do but to get it fixed, if you drive it too much without it you stand the chance of damaging your rack. :frown:

I have read all that I can find here and elsewhere about the dreaded power steering pump failure. My daughter's went out at about 104k miles in her '04 MCS. . . . All the classic symptoms exhibited, so we pulled the pump and had it rebuilt by a facility in Idaho (Module Master) for a reasonable price, then reinstalled it. STILL NO STEERING! We can hear and feel the pump running, and the cooling fan passed a bench test (though we discovered its fuse was blown - original cause of the pump failure maybe?). We are thinking that some driving of the car without the PS pump may have damaged the rack (as mentioned by ACallahan, above) or the steering column U-joint is buggered. It is REALLY hard steering.

Where do we go from here? Replace the rack and see if that is the source of troubles? How does one diagnose a bad rack? Should I trust one from a rebuilding shop that sells on eBay?

Are you sure the rebuilt pump is ok? The electric pump motor may run but is it actually pumping fluid around and running at the correct speeds under load?

If the rack goes there are usually leaks as fluid finds it way past the seals into the rubber gaiters/bellows each end but it may only leak internally.......the seals wear over time but a pump overheating can also damage the rubber seals inside the rack if the ps fluid gets very hot.

Some on Mini2 with strong arms have driven for a period of time without power steering with no reported damage to the rack but as said it is probably not recommended for any length of time.