Hissing From Drivers Footwell

RAG · Apr 11, 2016

Hi,

Hi have been reading a previous post in relation to this problem by rikkbb, great post and thanks for the info.

However I was hoping that someone may be able to provide the following additional info??

How do I diagnose what component is failing?
And where or how do I find the part number without removing the part?
Any pictures or threads other than mentioned for more information?
Any other useful info?

Thank you in advance for your help.

AndrewBates · Apr 11, 2016

if the noise goes away when you press the brake pedal its your brake servo that is at fault. apparently a ;large portion of engine parts removal is needed to install it as its near enough impossible to do otherwise

RAG · Apr 12, 2016

AndrewBates said:
if the noise goes away when you press the brake pedal its your brake servo that is at fault. apparently a ;large portion of engine parts removal is needed to install it as its near enough impossible to do otherwise

Thanks Andrew. I did suspect it was this failing. I had guessed it was a big ish job. Do you know any part numbers? The car is an S3 2007 8P 265hp with BHZ engine code.

Hookmonster · Apr 12, 2016

Yes brake servo.. if you touch the bake lightly does it stop hissing... 1860 quid at audi... gulp

Hookmonster · Apr 12, 2016

The servo was 250 quid.. the rest was labour

RAG · Apr 12, 2016

Hi Hookmonster,

Yes it does get quieter the more you put the foot on the brake. I already changed my pants after speaking with Audi earlier about the cost lol.
I am speaking to my regular performance specialists to see what they can do as I am thinking of getting a Sachs clutch fitted so maybe can be done at the same time with no or very little additional cost, fingers crossed.
Thanks for the info though. Don't suppose anyone knows the part number?

Hookmonster · Apr 12, 2016

Im afraid i dont know the part number but mine is a 2010 sportback with 59k on the clock with full audi service history ( car was originally purchased from there too.. and audi solihul were good enough to do it for half price.. 850 all in.. the lady on service dept desk asked the service dept manager and he cut the price in half...

Which makes me wanna go back for work that needs doing now...good customer service that...

RAG · Apr 13, 2016

Very good customer service and the price is a lot better than original quote. Audi quoted me £1200 but as I am upgrading the clutch I will get it done at the same time by the performance specialists. Thanks for the info.

madvw · Apr 18, 2016

Paid £450 to replace the brake server in my late 2008 S3 SB. This was at a main dealer and was after a 50% goodwill reduction for customer loyalty.

They did comment afterwards that they needed to remove the front, move the engine forward and drop the prop to get to it to replace it.

The strange thing was that after it was replaced, it had a 2cm-ish play at the top of the pedal, where it sort of clicked before you could feel the braking effort. Not a big deal, but it did feel different. Hissing was all gone after that.

RAG · Apr 19, 2016

madvw said:
Paid £450 to replace the brake server in my late 2008 S3 SB. This was at a main dealer and was after a 50% goodwill reduction for customer loyalty.

They did comment afterwards that they needed to remove the front, move the engine forward and drop the prop to get to it to replace it.

The strange thing was that after it was replaced, it had a 2cm-ish play at the top of the pedal, where it sort of clicked before you could feel the braking effort. Not a big deal, but it did feel different. Hissing was all gone after that.

Hi madvw,

Thanks for the info, I have found out that al though it is not a big job as far as the unit it self it is the accessing the part that takes the time. I would have thought that a part that may need replacing would have been designed to be accessed a little easier. Any way getting prices in now so with any luck it wont be to bad.

Ill mention to my chosen technician the issue with the brake pedal so as I do not get the same feel of 2cm play.

As far as I can tell I have no affects of the servo hissing apart from the annoying sound. Maybe ill have to live with it a little longer :-(

Lewbo · Apr 20, 2016

I had exactly the same problem on my 2008 S3 back in 2012 and was indeed the brake servo, got a local indi specialist to do it as Audi quoted £900 and they did it for £350 all in.

RAG · Apr 29, 2016

Lewbo said:
I had exactly the same problem on my 2008 S3 back in 2012 and was indeed the brake servo, got a local indi specialist to do it as Audi quoted £900 and they did it for £350 all in.

Where are you based? that sounds like a great price. I am in Sussex.

RAG · May 6, 2016

Hi,

Just wanted to update the thread to say that I have now had the Master Cylinder & Servo replaced and all is well and quiet. No more hissing from the footwell and the brakes are more responsive at lower RPM. Cost more than I had hoped but well worth doing. The master cylinder needed replacing as it had leaked internally and was the cause of the servo problem.

The VW technician who did the work said it took 5 hours and he did not need to disconnect the AC pipes but did drain the coolant. I think from what he said he took front bumper off, loosened the whole engine and had it on engine brace, he then pulled the engine forward a little and bingo he had the space to do the job. He had no need to disconnect the prop or drive shafts to do the job. Thought this would be worth knowing for those with the time and inclination to do this job themselves.

All in all it was less than half the price of Audi main dealer and as this mechanic is fully trained to the highest standard as a VW Technical Adviser I felt it was well worth price at £680 all in, including the dredded.

Now for the clutch.

Thank to all for advice and help on this issue.

Hookmonster · May 6, 2016

Glad its sorted

RAG · May 6, 2016

Hookmonster said:
Glad its sorted

Thanks for the advice Hookmonster,

Just as little side note. As I was talking with the tech guy last night I mentioned that my fuel economy had suffered recently and I could not work out why. Later in the discussion I explained that I had cleaned the Revo panel filter and treated it with dirt retention spray. He then piped up to say that may well be the reason for the fuel economy as it has probably caked the AMF gauge on the air intake with oil. I took it off and cleaned it and my MPG went back up from average 20-23 mpg to 27-34 mpg. Such an easy job to do that it is good advice to check and clean this regularly.

I am sure most of you knew this anyway. ;-)

Cambaines · May 9, 2016

@RAG I will try anything for better mpg, I average 20mpg, what's the AMF gauge? are you talking about the maf?

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RAG · May 9, 2016

Cambaines said:
@RAG I will try anything for better mpg, I average 20mpg, what's the AMF gauge? are you talking about the maf?

Sent from my iPhone using Tapatalk

Air Mass Flow sensor at the top of the engine in the black cover on the air intake. It had a two Torque screws holding it in. Remove it from the cover and give it a good clean with brake cleaner inside and out. Do you have the same engine?

Cambaines · May 9, 2016

I had a clean of that when I fitted my induction, I think it may just be my driving style maybe, mines a 2.0 tfsi? I get about 30mpg on a run

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RAG · May 9, 2016

Cambaines said:
I had a clean of that when I fitted my induction, I think it may just be my driving style maybe, mines a 2.0 tfsi? I get about 30mpg on a run

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Yeh that sounds about right depending on fuel and map settings.

Hissing From Drivers Footwell

My 2008 - S3 - 8P

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My 2008 - S3 - 8P

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My 2008 - S3 - 8P

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My 2008 - S3 - 8P

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My 2008 - S3 - 8P

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My 2008 - S3 - 8P

My 2008 - S3 - 8P

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My 2008 - S3 - 8P

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My 2008 - S3 - 8P

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My 2008 - S3 - 8P

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