[Seb_RS3]

I have an unknown knocking noise that keeps happening on my car. It’s more prevalent when the car is facing down hill but can happen at other times. It also doesn’t happen all the time. It usually starts when braking but sometimes can stick around after that and when it does is made worse again by braking. However once you come back to the car later the noise is gone.

I’ve been to the garage several times with it now and no one can find anything wrong. Just had the CV joint on the side where the noise is coming from replaced (front near) and a whole bunch of bushes changed. I’m at a complete loss now.

https://youtu.be/pyVNaoy-P5k

Does anyone have any ideas / has encountered this before.


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[0120raptor]

At time 2.49 that`s at wheel speed. I`d look at loose wheel nuts, cv`s, drive shaft bolts,cracked discs,badly warped discs,loose hub nuts,loose calipers.  

[Seb_RS3]

At time 2.49 that`s at wheel speed. I`d look at loose wheel nuts, cv`s, drive shaft bolts,cracked discs,badly warped discs,loose hub nuts,loose calipers.

Yeah sorry forgot to put the time stamp on there.

Yeah the noise always follows wheel speed. If you stick it in neutral while it’s doing it and increase revs it doesn’t change.

The wheel has been on and off a good few times now and the bolts feel solid so I don’t think it’s that.

The CV joint and the associated flanged shaft have just been replaced last week to no avail.

The disks look fine and there’s no cracking. Could a slight warp present with out the usual associated vibration?
Though I would have though that a warped disk would have been constant? Or could it be so slight that it would only present when exposed to heat?

As for all the other bits I’ll have to check the tightness for myself but the techs at the garage didn’t notice any loose fixing on the brakes etc. But like I said I’ll check them again to make sure.


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[Dooahhdoo]

Just thinking out loud I can hear the noise before 2:49 although not as obtrusive. Have you checked the wheels for a crack or buckle?

[RS3Dell]

Yeah sorry forgot to put the time stamp on there.

Yeah the noise always follows wheel speed. If you stick it in neutral while it’s doing it and increase revs it doesn’t change.

The wheel has been on and off a good few times now and the bolts feel solid so I don’t think it’s that.

The CV joint and the associated flanged shaft have just been replaced last week to no avail.

The disks look fine and there’s no cracking. Could a slight warp present with out the usual associated vibration?
Though I would have though that a warped disk would have been constant? Or could it be so slight that it would only present when exposed to heat?

As for all the other bits I’ll have to check the tightness for myself but the techs at the garage didn’t notice any loose fixing on the brakes etc. But like I said I’ll check them again to make sure.


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A warped disc would be felt as a pulsing through the brake pedal.

Do you get the noise when stationery as im thinking of a duel mass flywheel issue.... could be wrong tho.

Dell.

[Seb_RS3]

A warped disc would be felt as a pulsing through the brake pedal.

Do you get the noise when stationery as im thinking of a duel mass flywheel issue.... could be wrong tho.

Dell.

No noise when stationary in any gearbox setting (D/N/P) does that rule out the DMFW?

And yeah there’s no pulsing through the brake pedal that I can feel.


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[RS3Dell]

No noise when stationary in any gearbox setting (D/N/P) does that rule out the DMFW?

And yeah there’s no pulsing through the brake pedal that I can feel.


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I was just thinking aloud about the noise being speed related as you slow down.

Dell.

[MJRS3]

Hi, did you ever get to the bottom of this issue? My 8P has started displaying the same symptom under moderate braking too.
Cheers.

Michael

[Seb_RS3]

I've not gotten to the bottom of it yet as I haven't really looked any more into it. I suspect it's the brakes though as low speed vibrations did eventually present. (Though I don't know why the more pronounced knocking would only be present following spirited driving.)

 

They're due for changing again soon so I'll be able to see then.

[MJRS3]

I've not gotten to the bottom of it yet as I haven't really looked any more into it. I suspect it's the brakes though as low speed vibrations did eventually present. (Though I don't know why the more pronounced knocking would only be present following spirited driving.)

 

They're due for changing again soon so I'll be able to see then.

 

I was thinking it might be brake related too, but I have only just had all the discs and pads changed last year and visually they look to be fine. It feels like it may be related to the shifting of weight when braking moderately (hence why it occurs mostly after spirited driving). I need to find the time to get a proper look under the car and check that nothing is loose/worn at the rear.

 

If I have any joy in pinpointing the issue I'll give you a heads up Seb.

 

Michael 

[flybynite]

Have you checked the play in the transfer case bearings. Lots of those seem to be starting to go, good to catch them before the play in the bearings takes out the bevel gears. Get the oil in the transfer case checked as I think that has been the problem for some.

[MJRS3]

Have you checked the play in the transfer case bearings. Lots of those seem to be starting to go, good to catch them before the play in the bearings takes out the bevel gears. Get the oil in the transfer case checked as I think that has been the problem for some.

Hi, I had the transfer box oil replaced last month along with the haldex, stronic, rear diff and engine oils.

The work was done at an Indie who is very thorough and nothing was flagged at the time. It's very frustrating but then again the 8P is now over 10yrs old so weird noises are bound to start occurring I guess 

 

Michael

[MJRS3]

Morning gents, just a quick update on this in case it helps anyone in the future.

The issue has now been resolved on my car- it turns out it was the inner edge of the metal backing plate of the front brake pads (EBC Redstuff) catching on the central hub of the brake discs (Reyland bolted discs). The pads have been chamfered down to give clearance and the noise has gone. I'm guessing that as the pad material wore down over time the inner edge of the backing plate was able to come into contact with the disc hub and heavy braking through spirited driving pushed the material harder against the disc.

 

Mike

[Seb_RS3]

Morning gents, just a quick update on this in case it helps anyone in the future.

The issue has now been resolved on my car- it turns out it was the inner edge of the metal backing plate of the front brake pads (EBC Redstuff) catching on the central hub of the brake discs (Reyland bolted discs). The pads have been chamfered down to give clearance and the noise has gone. I'm guessing that as the pad material wore down over time the inner edge of the backing plate was able to come into contact with the disc hub and heavy braking through spirited driving pushed the material harder against the disc.

 

Mike

 

 

Could you seen obvious signs of this contact on the backing plate? (Ie was it all scratched clean where it had been making contact?)

[MJRS3]

Could you seen obvious signs of this contact on the backing plate? (Ie was it all scratched clean where it had been making contact?)

Hi Seb, the only visual clue was the outer most edge of the disc hub had been worn down to bare metal.

[MJRS3]

You can see how it was before being remedied on the attached photo.

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