Polo GTI "whistle" sound

[PoloGTInoob]

Hey guys

I posted about this before and no one could hear the sound in my video so im going to try again

I have a Polo GTI which is otherwise fine and has just had a minor service (oil change) at VW. However, intermittently, it makes a weird high pitched whining or whistle sound. It only happens maybe 5% of the time. I feel like it is brought on by driving in heavy traffic. But take that with a pinch of salt.

Oil and coolant temps normal, its not affected by RPM, fans and AC turned off, same with infotainment system and radio off or on. Its noticeable when idling, i think the sound remains when i drive off, but its harder to hear.

please, just tell me someone can hear the sound in this audio Its subtle, but you can hear the engine rumble and a whining sound (almost like a flute) that my phone only just picks up. Any ideas? It almost sounds like video interference, like a digital flute sound. if you hear that, its the sound the car is making, not the video.

As it is intermittent, ive not been able to take it to a VW dealer while its happening.

https://youtube.com/shorts/v6fOC1JbXaE?feature=share (maybe use headset to hear clearly)

[SRGTD]

I can hear it. No idea what it is though - sorry .

Can’t say I’ve noticed a similar noise with my 2020 GTI+, although I have my radio on 100% of the time, so I’d be unlikely to hear it as the noise is very subtle in your video clip. I’ll try and remember to turn the radio off next time I use my car and I’ll have a listen.

[TrebleTA]

Do you have the fan on in the car, could not see in the video, bit the squeek seems to be something rotating, can it only be herd inside the vehicle?

I'm thinking the interior fan maybe getting power when it's off

[PoloGTInoob]

The fan and AC are off. I had a listen under the bonnet and couldn't hear the noise. I even let the engine warm up so that the engine (radiator) fan came on but couldn't hear it.

[TrebleTA]

So it's inside the car. Is there a cooler on the UI.
Else and maybe if your car has the engine speaker, anyone know how they work are they vacuum or powered. If powered could be that.
Else anyone know the fuse for the in car fan. Removing that would exclude it.

[SRGTD]

So it's inside the car. Is there a cooler on the UI.

That’s a possibility.

On a previous VW I owned, I seem to remember I could hear the infotainment unit cooling fan running after I’d turned the engine off.

[PoloGTInoob]

I wonder if this could be it. It would make sense that the infotainment fan would only come on after I've been driving for a while. It continues when I turn the system off but you'd expect the fan to continue anyway.

[SRGTD]

I wonder if this could be it. It would make sense that the infotainment fan would only come on after I've been driving for a while. It continues when I turn the system off but you'd expect the fan to continue anyway.

Worth trying a couple of journeys with the infotainment unit switched off to see whether or not the noise is still present.

[Harrihealey02]

The infotainment fan is located around the glovebox compartment and you can hear it but it doesn’t sound like that sound you have. In my new polo the fan is a lot quieter than the last polo I owned from 2019, but another thing it could be is your air conditioning pump as it sounds like some sort of pump. When the car AC is switched off, it does not actually fully turn off as you would assume, it still runs at about 5 or 10% just to prevent moisture build up and you can see it taking energy when you use the multimedia energy display that it still draws power even when it’s switched off.

[PoloGTInoob]

One thing I should clarify is the sound goes away completely if you turn the engine off and will resume immediately when it's turned back on. But it's not affected by turning the infotainment system on or off, which might rule it out.