New ABY owner with humming noises....

[JamesHarrold]

New on here guys so be gentle
Bought my 93 ABY coupe about a month ago now and have to get this off my chest.......
Its the best damn thing I have EVER bought
Been looking for a clean genuine example for about 2 years so am well happy now.....
However, 2 weeks ago I noticed a humming/whining noise just after heavy braking.
For example, braking for a roundabout (no noise) and after about 4-5 seconds it sounds like someone has a foghorn under the bonnet!
It has been getting worse over the past couple of weeks, so much so that it is now happening nearly all the time the brakes are applied
If I move the steering wheel whilst it is humming at me, it does stop briefly, but starts again soon after.
Been searching on here for similar issues and it seems to be pointing towards the brake pressure accumulator....anyone experienced the same thing or have any ideas?
Cheers
James

[shaun5]

Hello and welcome First thing we need to know is what brakes are you running/ standard?. I have got the mov-it set up and i get the same symptoms if i brake really heavily. Nothing wrong with the brakes and when they cool down no noise.

[JamesHarrold]

Thanks for the reply Shaun5....
It has 996 calipers with A8 discs, standard rears.
Dont think its a friction issue - sounds like an air leak of somekind, or a pump on the way out?
Really hope its not expensive...

[SteveH]

It doesn't sound familiar to me, does it only happen whilst your moving? You can get some funny sounds from the ABS if the wheel sensors are incorrectly positioned.

to the forum

[Acidburn]

does the noise go away when you brake?

[JamesHarrold]

The noise doesnt seem to change when you brake and I have just been outside and stamped on the brakes in the driveway - HARD....and its still there!
If I move the wheel slightly, it does get quieter or even stop....

[dest]

Sounds like the same as mine, you need to put some copperslip (or similar) on the back of the pads

[bluetack]

I have a similar noise on mine 93 ABY. I am pretty sure my noise comes from the blower fan inside /under the dashboard.
My theory is this, the fan is running quietly and when you brake heavily it moves the bearing and then the noise begins.
I also sometimes get the noise on icy mornings and more strangely it goes away when you turn the wheel. This is something to do with the bearing moving.
One test is to turn the fan off when the noise is on. Mine always goes away.

[JamesHarrold]

Thanks for all the info guys....much appreciated
Will try turning the fan off next time it happens to see the result.
Gotta change the pads soon, so will try the copperslip idea....although I must say it sounds more terminal than that!
James

[GT500]

Is it a humm or a humming vibration?
My guess if its not the fan would be tired engine mounts, engine touches sub frame,
you could try a washer between the mount and the engine mounting on the passenger side (easy to get to) just to lift it a little. Then try it, if it helps I'd be ordering some new mounts.
Mine does this at the mo, but more when using engine braking and brakes.
HTH

[QuattroFever]

I got 996's and a8's and i get a humming as well. it goes through the whole car.

only starts when its warm. goes away when I press the brake then slowly fades back in.

[JamesHarrold]

Glad I am not the only one then QuattroFever
Sounds like the same problem.
Do you know what causes it or how it can be rectified?
Wonder if anyone has the same problem using standard front brakes....
James

[dest]

Its what I said

[JamesHarrold]

Thanks Dest
Will try that tonight and see what happens....
On the same subject (kinda) I have to replace rear pads and discs soon - Anyone have any suggestions or is it best to go for standard from GSF or similar?
Cheers
James

[BRY]

If you're not upgrading disc wise stick with standard and get the winding in tool, as it makes it that much easier it's worth the cost of it.