Single knock when braking or accelerating...

[dieselmonkey]

Hi all,

Went out in the car today and ended up in standing traffic as usual...

As it was a nice day, I decided to wind down the windows. Soon after doing so, it became apparent that there was a squeaking noise coming from the N/S front wheel. Also, as we went on... stop - start, stop - start. I started to notice a strange knock when pulling away and again when breaking. Less so on gentle braking. As I have recently had some new wheels fitted. I checked to make sure that the hadn’t worked loose... This was not the case. I can see the discs and pads, between the alloy spokes, they look fair... a bit worn, but not down to the bone... Is it possible the calliper may have worked loose or something here? The noise does sound almost like it is coming from underneath the engine bay.

If I throw it in reverse and hit 5 mpg then brake hard. There’s a definitive single knock. Then going forward, sometimes there is a single knock on acceleration, but definitely when hitting the brakes. Not forgetting the persistent squeaking noise…

Any ideas???

P.S Also went down to Halfords today to get some replacement wiper blades, and to my surprise they don’t sell them for my model… 2001 A4. Is this a main dealer purchase?

[Dave Avant]

Pads can move in the caliper/carrier but not excessively to cause a knock.

If the wheels are correctly torqued up and are the correct fitment, they shouldn't cause any probs. A worn suspenion part, like a ball joint or pivot could cause a knock.

Have you got a decent jack? Try jacking it and waggling the wheel tofind any 'play' in the suspension parts. Are get a mate to listen next the wheel when you move.

Which wheels are they, did you notice the knock before getting them?

The wipers are Audi's own and you can't get off the shelf wipers from Halfords. They pretty expensive at the dealers, but I got mine from GSF parts (German Swedish French). Its the clip that holds them on. Nice and quick and easy to change, just that you can only get them at the dealers or specialists. The rear one (Avant) I need to get from the dealer as I've tried a few off the shelf types as it just clips in, but they are all too wide or the clip doesn't hold them.

[dieselmonkey]

Cheers Dave Avant...

I have a trolley jack. I'll have a look tomorrow. What exactly should I be looking for? I have tried pulling and pushing the wheel whilst on the ground to see if there is any play and also bouncing on the front wing/suspension to see if the knocking noise happens then, but I couldn't replicate the problem.

The wheels are RS6 18" replicas, I have had these for about 1 month and the noise has only just started to happen.

Your right the wipers are easy to remove. I'll try GSF for the parts. It's only the rubber on the drivers side. However, I have tried cutting the refills once before and never again... Easier with the complete unit.

Mark

[RickT]

in regards to wipers...

im not sure where you guys are from.. but i always go to Andrew Page who supply BOSH wipers and get them at trade price..

The Audi ones are BOSH but just come in the audi box...

It cost me £15.99 for the better ones pair.. (theres 2 options)

RiCKT

[Dave Avant]

Cheers Dave Avant...

I have a trolley jack. I'll have a look tomorrow. What exactly should I be looking for? I have tried pulling and pushing the wheel whilst on the ground to see if there is any play and also bouncing on the front wing/suspension to see if the knocking noise happens then, but I couldn't replicate the problem.

The wheels are RS6 18" replicas, I have had these for about 1 month and the noise has only just started to happen.

Your right the wipers are easy to remove. I'll try GSF for the parts. It's only the rubber on the drivers side. However, I have tried cutting the refills once before and never again... Easier with the complete unit.

Mark

Try grabbing it and giving it a good waggle laterally and vertically. Or on ball joints I have used a big screw driver or jack handle, stuck it between suspension parts and as they say in America - Levered it to see if there is any play.

[Dave Avant]

in regards to wipers...

im not sure where you guys are from.. but i always go to Andrew Page who supply BOSH wipers and get them at trade price..

The Audi ones are BOSH but just come in the audi box...

It cost me £15.99 for the better ones pair.. (theres 2 options)

RiCKT


Just over t'other side of Pennines. The wipers I got were £15 (Pair), not Bosch, but German, can't remember the name. Might remeber Andrew, seen one his vans around here.

[Huweth]

Could also be the cv joints or wheel bearing, though thats probably less likely than a worn bush.

[dieselmonkey]

Hi all...

Well some good news...

First off got the wipers sorted... Called Andrew Page but they confirmed my fears that the 2001 on model has to be sourced direct from manufacturer. Called local Audi dealer, they charged me £17 for driver’s side - £14 for passenger... Done and dusted now...

As for the knocking noise... Well this got considerably worse over the last couple of days... Checked the wheel nuts, but to no avail... Tight as you like.

Now a noticeable vibration was evident at high speeds... Now certain it was pointing towards a dodge driveshaft, I jacked it up on the passenger side and shook the wheel around… And to my amazement the bloody thing was all over the show.

Still unable to move the wheel nuts… I dropped it and loosened all the nuts. Jacked it up again and removed the wheel. The brake disc was rocking around, but according to the Haynes manual, this is normal. They are held in place by the wheel nuts.

Cleaned out the threads with a bit of WD and re-fitted the wheel… Now the wheel is tight up against the hub, all suspicious noises eradicated.

My concern now is that, there could be some unseen damage to the wheel and or hub… Is this possible, everything looks ok…

[Niall76]

I'd say that if it's all tight now and there's no noise you've gotten away with it guv.

If the wheel bearing was away then you'll hear a distinct rumble from it.

If the wheel was dameged then you'ld feel it.

If all is quiet and smooth then karma has been restored.

[onzarob]

I agree niall76, the wheel holds the disk to the hub, the hub is held inplace by the hub nut.

Rob:D

[Col]

Don't laugh at this !!!

But...

According to dear old VW themselves an unexplained knock can sometimes be caused by the lock striker bar for the doors.

Try rapping one or two turns of tape around them and see if it goes away, assume Audi locks would be the same.

[dieselmonkey]

Good news then...

I'll just keep my eye on the wheel, just to make sure it doesn't loosten up again.

Thank's again...

[AudiA62.5TDI]

Hi all,

Went out in the car today and ended up in standing traffic as usual...

As it was a nice day, I decided to wind down the windows. Soon after doing so, it became apparent that there was a squeaking noise coming from the N/S front wheel. Also, as we went on... stop - start, stop - start. I started to notice a strange knock when pulling away and again when breaking. Less so on gentle braking. As I have recently had some new wheels fitted. I checked to make sure that the hadn’t worked loose... This was not the case. I can see the discs and pads, between the alloy spokes, they look fair... a bit worn, but not down to the bone... Is it possible the calliper may have worked loose or something here? The noise does sound almost like it is coming from underneath the engine bay.

If I throw it in reverse and hit 5 mpg then brake hard. There’s a definitive single knock. Then going forward, sometimes there is a single knock on acceleration, but definitely when hitting the brakes. Not forgetting the persistent squeaking noise…

Any ideas???

P.S Also went down to Halfords today to get some replacement wiper blades, and to my surprise they don’t sell them for my model… 2001 A4. Is this a main dealer purchase?


Hello

I have the very same annoying "single" knock and only happens when braking to a stop. Did you use an Audi dealer or an independant?

[dieselmonkey]

Hi, As you will see from the rest of the post, the noise was down to a loose wheel. The knocking noise was the brake disc moving back and forth when braking and accelerating.

Since then the driver’s side wheel has also worked loose. I'm kind of hoping it’s due to the wheels being new and bedding in. Otherwise, they are just cheap and cr@p...

Is this normal for new alloys???

[onzarob]

Hello

I have the very same annoying "single" knock and only happens when braking to a stop. Did you use an Audi dealer or an independant?

I would suspect your knock to be a bush or suspension knuckle.

I would advise you start a new thread to avoid confussion with this topic.

Cheers

Rob:D

[guyg]

Pads can move in the caliper/carrier but not excessively to cause a knock.

They did in my Passat - I changed the front pads a while back and couldn't get to the dealers so fitted pattern pads.

Immediately after fitting the new pads, I got a resonably loud 'clunk' from the offside front on braking, especially when manouvering at lower speeds, switching from forward to reverse and vice-versa.

Now there's a few miles, it comes and goes a bit with the brake dust, but it's still there. A mate who works in a garage tells me that pattern parts often have crap tolerances. It's irritating, but not enough for me to change the pads...

Cheers

Guy

[AudiA62.5TDI]

Guy

Many thanks for the reply. I appreciate it.

I decided to book it in since I had a "play" with it last night. Everything seems quite tight.

I am hoping that it is the brake pads and nothing else more serious/expensive.

Apart from your pads, has your Passat been a good purchase. Time will tell with my a6............

Regards

Danny

[guyg]

Hi Danny

I had a 1995 A6 [2.0 ABK engine] which I bought at 60k and I added another 120k over 6 years. I sometimes wish I still had it. You could almost climb in with the engine, and I could change the cam belt myself in 15 minutes.

Apart from the usual comsumables the only things I had to change was a throttle position sensor and a set of hydraulic cam followers at 120k.

I haven't been so lucky with the Passat, two of the windows have packed up and VAG don't sell replacements for the broken clips seperately, they want me to by the whole panel and regulator mechanism. I also had the rad fail at 80k and because the car is so akward to work on, the job cost over £400 [the rad itself was £80]. I've also had some fun with the alarm system but hopefully this will be all...

I would have got another A6 myself but didn't quite have the budget; I hope you''ll be happy with yours.

All the best

Guy

[stuartliddell]

Guy

Many thanks for the reply. I appreciate it.

I decided to book it in since I had a "play" with it last night. Everything seems quite tight.

I am hoping that it is the brake pads and nothing else more serious/expensive.

Apart from your pads, has your Passat been a good purchase. Time will tell with my a6............

Regards

Danny

Hello danny,
i have the same problem you have had/got! When you took your car in what did they say was wrong? My problem only started when i had my discs and pads replaced!!

regards stuart

[jammapic]

I think I have this same knock... is the one everyone is talking about, like a deep 'thud'.

I also can only to get it to do it once. If I brake hard it does it - and then not again, until I accelerate hard, when it will do it. Then it will do it if I brake hard (if you all follow)

I also (ocasionally) hear it when I corner very hard!

JP