Whistle noise coming thru dash of my 2002 BMW Z3

SOURCE: 1997 BMW z3 1.9 L.

I had the same problem on my 98 z3 1.9. I sprayed a little silicone spray lubricant from the bottom of the steering wheel into the crack between the stationary and turning parts. That took care of it (for a couple of months now).

SOURCE: 2003 BMW 325i will start but making noise

It might be a faulty power steering pump. Try checking the level of the power steering fluid. It is probably best you have your power steering system checked by a mechanic.

Does the noise occur only when the vehicle is moving?

Try moving the steering wheel from side to side, while stationary (but don't do it too often, or you might damage something). If the noise is still present when the car is stationary, then it probably is the power steering system.

If the noise only occurs while the vehicle is moving, it could be a problem with the differential/final drive, or even wheel bearings.

SOURCE: BMW Z3 2001 3.0i Power steering is completely out.

Sounds like it. Loosen the belt and try to turn the pump by hand. It should turn quit easily. If it doesn't, it will need attention.

SOURCE: my 2002 bmw 525i makes

Please describe the noise. Is the noise inside the car or beneath the car? Is it a squeak, a clink, or a grind?
If the car has over 100k miles on it, and it makes a hydraulic pump whine when you turn the wheel, look in the reservoir and see if the fluid is still bright red. If the fluid has turned brown, many (including me) have been able to quiet the whine by removing the reservoir and flushing the gunked up screen in the reservoir out with solvent, and then replacing the power steering fluid with fresh fluid.
If you do this yourself, be prepared to dedicate a whole Saturday to the job. If you have any drips from your power steering hoses (common) this will give you the excuse to get in there and replace the leaking hoses while you are at it.

SOURCE: Whistle noise inthe front of the engine of bmw z3 2000 2.3

a leak in a hose or a bearing on a motor