Is the power steering fluid level ok?I have a 2012 Mini Cooper s Bayswater I bought the car about 6 months ago with no problems but now it’s develped a very high pitch noise when it’s moving it’s not the breaks and it does it at 10mph-60mph very loud when pulling away from a junction it’s not the window or the breakpads ive took it back to place of purchase they have no idea what it is and can’t replicate the noise but every time I drive it it’s there and very annoying something the noise only occurs once the car is hot for excample once it’s been driven 15 mins or so does anyone have any idea please help!
Can you affect the noise by turning the steering wheel as sharp as it is safe to do from right to left to right again?
Can you affect the noise by applying the brakes at various levels?
Is the A/C system off? Does the noise change if you turn on the A/C? Play with the cabin vent fan control?
What about windows? Enlist the help of someone to push against each of the windows (other than your driver window you can push that yourself) to see if the noise can be affected by pressure against a window.
If the car is fitted with a run/moon roof can you press against this and affect the noise?
I am not aware of this with the Mini but with one car I owned (Boxster) the front trunk lid leading edge was positioned quite a bit lower than the trailing edge of the front bumper cover. Some owners thought this wrong and unsightly and adjusted the lid's edge to be flush. The car developed a wind noise.
My point is you need to consider possibly a hood or even a hatch lid may not be adjusted properly and could account for the noise.
Added: Forgot to mention but the noise could be a failing water pump or possibly a failing accessory drive idler/tensioner roller bearing. The car needs to be inspected for signs of any issues like a water pump or accessory drive problem.
Do the tires show any signs of odd wear? Feathering of the tread blocks of front or rear tires? Signs of roughness of the surface of the tread blocks. Normally the rubber surface wants to be smooth. If not this can be a sign for wheel/tire alignment which can cause the tires to make noise.