Whining and No Hot Air Coming From Windscreen Vent?

[jdw88rm]

Hi guys,

driving home last night, I got bored with my music so was driving in silence and noticed a whining noise (almost like fast air moving over a gap like a draught) and also there was no hot air coming from windscreen vent unless I turned it up full. All other vents worked fine?!
Anyone ever had anything like this or could think what it could be?

Cheers!

 

[quattrojames]

It will be a stuck motor on your heater adjustment mechanism.

This will get you started:

http://www.audi-sport.net/vb/a4-a4-cabriolet-s4-forum-b6-chassis/49307-help-windscreen-demister.html

 

[jdw88rm]

The demister blows air but its just not hot!? The other vents around the car still blow hot and cold!?

 

[quattrojames]

It will be a stuck motor on your heater adjustment mechanism.

It's in the drivers side footwell from memory.

I think it might be a yellow mechanism, but I'm not sure. Hopefully someone can set me right.

 

[jdw88rm]

Heating now seems to be fixed but whining noise is still there. Comes on at around 40mph and mostly when I accelerate? Not sure if it's always been there but only noticed it when I was driving along motorway with no music and now I know it's there I keep listening out for it?

 

[jdw88rm]

Bump - any theories?

 

[PetrolDave]

Do you have all the face vents closed? If it tries to direct air to them and they're all closed it will whistle.

 

[jdw88rm]

All vents closed yeh. Ive had a google and wheels bearings/pulleys seem to whine when on their way out??

 

[jdw88rm]

Bump

 

[quattrojames]

I'm not really sure what you're asking?

About the windscreen vent or the whining?

It's no use bumping without providing any more information, this is why you haven't had any replies.

Is it engine dependent? Speed dependent? Does it go when you dip the clutch? etc etc

 

[jdw88rm]

Sorry, I'm just wondering what this noise could be... it's not linked to the heaters at all. It starts at around 30mph and gets louder the faster I go. It's like a whine or like a draught (high wind passing through an enclosed space). I tried taking a video but you can barely hear it on there

 

[IanFM]

What engine do you have?

 

[jdw88rm]

1.9tdi 02 plate

 

[Mike_B]

Quite probably a wheel bearing.

 

[PetrolDave]

All vents closed yeh.

Try opening one vent a tiny amount...

With all the vents closed there's nowhere for the air that is being pushed in as you drive so it builds up in the heater pipework and finds the "easiest" way out, which is usually squeezing past the small gaps in the face level vents - hence the whistling. If you crack one face level vent open slightly it's got an easier route out and the whistling stops.