Whistling noise at 60mph

[kop77audi]

Hi all,

my A4 S-line has started to whistle when I reach speeds of about 60mph, the noise seems to be coming from the bottom right hand corner of the windscreen (as you sit in the car) or it could even be a vent as its very hard to pin point it.....

it gets worse when you let down either of the front two windows and it doesn't matter if you open it an inch or 6 inches it will sound louder,

with the bonnet closed I stuffed a scarf down under the wiper arms and went for a test drive and it worked, the noise stopped

I thought it could be the wipers but it still does it with the wipers working,

the only other thing to mention is that the aircon has stopped, the econ light is on continuously,

any ideas?

thanks.... :Blush:

[kop77audi]

I've been going for test drives since I posted and I've found (accidentally) that as soon as I turn on the heating it stops it from happening,

I was traveling at a constant 65 mph and I switched on & of the heating several times and within about 2 seconds of switching it on the whistling stops but sometimes it does whistle again at 70mph+

[kop77audi]

Could it be happening because the aircon has completely leaked out as the whistling only happens when cold air in on.... ?

[Roonster]

Purely for elimination purposes, It's worth checking all the Rubber Seals and trims around the Bonnet and Scuttle area. Make sure there is not a build up leaves in the base of the Scuttle/Fan Housing. Worth ruling out (and free) before looking at more elaborate solutions.

[kop77audi]

Thanks for that, yes I had a good look around that area and all is fine...

I have just discovered something else though, the belly pan is missing, it was not put back on by the garage who fixed my steering problem recently,

I rang them and its still in the workshop, hopefully when I put this back on it will solve the problem.... hopefully!!

[kop77audi]

Right... so I put back on the belly pan and it made no difference,

just been for another drive and it whistles with the heater off and as soon as I switch it back on the whistling noise lowers and even stops at some speeds,

here's the thing though.... even after I turn on the heater to stop the whistling if I switch on the re-circulation switch it whistles again,

I took out the glove box and had a look at the flap and it seems to close fine,

I'm lost..... any ideas?

thanks,

[kop77audi]

Bump..... :confused:

[kop77audi]

Hi again,

just got my car back from the aircon guy with the aircon fixed & working again but it still didn't solve the whistling noise,

the only thing that helps is turning on the fan, whether it be hot air or cold air, fast or slow, it will almost stop the whistling noise..... until you hit about 70mph!

once again I stuffed a scarf down under the wiper arms all along the black plastic mesh thing and it works.... it doesn't make a sound,

could it be that the windscreen is letting air?

I also think that the front windscreen was replaced at some stage because it doesn't have the Audi symbol like the others but why now after 12 months of ownership.....

last thing to mention is that about a week before this noise started to happen I had the steering rack out & reconditioned, whether that has any bearing on it r not!!

any ideas guys, I'm really struggling here..... thanks

[micheal balbrig]

Could it have anything to do with the pollen filter,or housing cracked,these were probably disturbed when working on rack / removing battery.Its just peculiar
that whistle tone changes with fan operation. (check to see if third bolt in rack was replaced, maybe wind is whistling through hole)
Because you seem to get rid of noise with the scarf across scuttle,why not concentrate here to eliminate problem.
Maybe you could try sealing areas with tape temporarily to try to pin point exact area that is causing noise.

[kop77audi]

Hi again,

can anyone tell me what this for, it was just lying there beside the pollen filter housing,

it seems to go back into the car via the passenger side front wing but I cant find what its supposed to be attached to?

2457824579

[kite]

Is the other end connected to the battery ?
Looks like the vent tube to me, not sure where the end goes.

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[kop77audi]

Yes... its vent pipe that goes to the side of the battery, but it didnt fix my problem

this is what I've done so far,

Removed the wipers & tested

Removed the wiper arms & tested

Remove the plastic grille under the wiper arms & tested

Remove the pollen filter housing completely and stuffed the opening to the fan with rags & tested

Lifted the lid of the ECU housing and stuff rags around & under the ECU & tested

Put silicone along the bottom of the windscreen when the grille & wiper arms etc was off & tested

Put everything back on and stuff rags all along the bulk head, all around the master cylinder, all around the battery and all around the ECU box & tested

Put a blanket all along the top of the bulkhead (found it hard to close the bonnet) & tested

I spoke to a few mechanics and they are at a loss, Just doesn't make sense!!!

[kite]

You could have an air distribution flap sticking.
Scan for faults and reset the flap motors in badic settings.
You will need VCDS for this.

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[kop77audi]

You could have an air distribution flap sticking.
Scan for faults and reset the flap motors in badic settings.
You will need VCDS for this.

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I forgot to mention that..... my guy scanned for faults & found none,

should I ask him to reset them to basic settings anyway or is that something to do if a fault is found,

thanks again....

[micheal balbrig]

Just a thought !!!
The whistle that reduces when heater is turned on, is it possible that it is current being used that is altering whistle intensity.
If you were to turn lights on would it do similar?
Just something to try if flaps don't cure problem.

Have a look at the rubber seal where rack enters bulkhead
Also it might help to use a stethescope (with someone else driving) to try to locate problem.
Some motor factors stock same.

[kop77audi]

No.... I'm afraid that didnt work either,:Blush:

[kite]

You can do an output test to see if they are moving correctly.

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[kop77audi]

thanks, sorry for sounding stupid but can you explain an output test a bit more,

at least I'll know what I'm taking about tomorrow when I go back to my mechanic.....

[kite]

An output test can be performed with VCDS. It shows if the flap motors are moving correctly.
If they don't you can try a reset in basic settings.
Flap motors are known to jam and can be removed and opened, sometimes a regrease gets them going again.

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[kop77audi]

thanks for that....

I'll get my guy to try it out,