Ford Fiesta, spinning whistling noise

[Emma0909]

Hi everyone,

so ive been experiencing a high pitched whistling noise on my car for a fair few months, used to be when I passed approx. 50mph once I’d done abit of distance (maybe because the car had warmed up). Visited the garage and suggested maybe my wheel bearings, but as I hadn’t yet recorded the sound and they could not hear it themselves, they couldn’t find any obvious faults. Since the sound has got a lot worse and had now turned into almost a spinning noise. It’s still after I’ve drove around for a bit but a lot more frequent and at lower speeds, sometimes even when I’m initially pulling away. Any suggestions at what this could be would be massively appreciated

(if helpful will try to upload recorded noise)

[Tdci-Peter]

4 hours ago, Emma0909 said:

suggested maybe my wheel bearings,

Modern wheel bearings often make a speed dependant droning noise. Not really a whistle, but much higher than the rumble that is usually heard with older bearings. It carries on regardless of gear, and even in neutral. As it gets worse, it will usually change appreciably when cornering, but initially it may stay the same regardless of bends. There will most likely be no detectable roughness, vibration or sound when turning or twisting the wheels by hand.

Turbo hose leaks (if you have a turbo) can hiss or whistle, but only at fairly wide throttle openings. Will go quiet as soon as you release the throttle.

Air noise, perhaps round bits of heat shield coming loose under the car, or some other change to the aerodynamics, can give a whistle which is very speed dependant.

Aux belts and some equipment on them like alternators, can whistle, this will be rpm dependant rather than speed dependant. So will vary with what gear you are in.