Weird whistling noise coming from engine bay...?

[Parky]

Before anyone suggests it no I don't have a small bird living in my engine bay...

This has been going on a while, sounds like it is coming from the right hand side of the bay and the pitch alters with the speed of the engine (faster = higher pitched, slower = lower pitched)... It's literally like a whistling sound like wind blowing through trees.
It isn't loud but is noticeable.

It's not the turbo as I've recently replaced that and it did it before as well, I've checked ancillary belts and they're all good, nothing rubbing on them, and I'm at a loss as to what it could be.

It only happens under load, I haven't been able to replicate it on a ramp, and the fact that the pitch changes with the engine speed tells me it's something ancillary, alternator bearings or a pump on it's way out maybe?

Anyone experienced this before? It's getting on my tits now and I want it sorted!

Edit, it's both on and off boost, so not likely a leaking air pipe.. Right?

 

[Chriscooke]

When you say it only happens on load are you sure it's not a window seal thats gone? these can whistle and get louder with speed. Have you tried driving along and depressing the clutch to see if it makes a difference?

 

[spoonman]

its not coming from your front right speaker or tweeter by any chance? the interference noise caused by alternators omitting too much electrical discharge and interfering with voltage signals from your battery which sometimes gets picked up by audio

 

[Auss15]

Sounds like a gasket to me..

 

[S15_SAM]

Just to throw my 2 pence in.

Sounds like either gearbox whine, or alternator bearing.

But without hearing it, it could be any of what's been suggested above. Can you get a video?

 

[Parky]

Chris, it's not speed related, definitely changes with the revs. I'll try dipping the clutch and see what it does.

Spoonman, it does it regardless if the stereo is on or off, I thought interference as well.

Auss15 all the gaskets were replaced just before xmas, with decent gaskets and all studs and hardware upgraded, they all still seem good.

Sam I'll try and get a video later. I was having issues with the alternator belt being squeaky and coming loose so I'm thinking the two could be related..

 

[Parky]

Well Spoonbob seems to have nailed it, despite what I said above, I went out, car started whistling, turned the stereo off, and the noise disappeared. F'in lol. And yeah it seems to be the front right speakers. Glad it isn't anything engine related. :thumbs: