Strange "scraping" noise??

[pauldoherty]

HI ,

I have an issue with my May 08 A4 2.0 TDI 143 - ( for a start the brakes have been squealing since 14k and I have now done 48k!) every couple of months or so, and for no apparent reason, I get a noise when driving that can best be described as a metal scraping noise, that lasts for 10-15 minutes and then goes again. I have asked Audi to look at it when in for a service but they could not find any problem.
It sounds that aggressive that I cannot believe that something isn't getting worn away - first of all I thought it was something making contact with one of the wheel, and I asked ATS to have a look at the wheels when getting tyres done, but no damage??
There is absolutely no point in me taking the car to the dealer, as they would not hear the noise and would just tell me to keep an eye on it, and I am not sure why the brakes are squealing under light braking; or indeed if the 2 issues could be related.


Has anyone any ideas?

[moose-P]

May not be the same thing, but something to check ...... in France last year we started to get a "grindy" sort of noise when braking hard, fully loaded ... but when running normally there was no problem ....... a couple of days later, descending Mont Ventoux, the grinding noise came back with a vengeance so stopped to look at the brakes through the wheels - the rear pads looked low, but still had a few mm of material on them Drove on again, and as the downhill continued, so did the noise ..... so stopped and had another look

What was happening turned out to be quite simple - the discs themselves had worn slightly, and the slight lip this created meant that when braking hard the backing plates for the pads just came into contact with the lip around the outside of the disc - a new set of rear pads and all was OK again

[pauldoherty]

Cheers Moose-P,

To be honest that was the only thing I could put the brake squealing down to - the rear pads, as the front have been changed. And, as there are lips on the discs, this may be the answer. Thanks, and I will certainly look into it!

[Mclucker]

New pads alone may not work; usually the discs need to be turned down or preferably replaced.

[B6Andy101]

How about a bit of grit / small stone between the pad and disc. Lots of it about at the moment.

[gibbyd]

How about a bit of grit / small stone between the pad and disc. Lots of it about at the moment.

Agree with this as I had this problem back in Oct one morning, screeching through my Village with everyone looking and thinking how glad they were not to have a new Audi. The noise was unbelievable, then just stopped, just like that!

[pauldoherty]

A stone or bit of grit was the first thing that I thought of, but it has been happening now for 30 odd k, so any foreign body would have desintegrated by now.

[rila75]

This is due to the brake pads holder not returning back in position so pads are touching the brakes disk. i.e holders are stuck. Usualy hapens in cold whether when the hand brake has been applied for a long time. After the car is driven for a while the "stuck" looses itself. don't apply the handbrake in cold whether when car stationary for long time or have a garage to look into it and mayby clean the hydravliks. i t my need new brakes fluid as well.

[B6Andy101]

This is due to the brake pads holder not returning back in position so pads are touching the brakes disk. i.e holders are stuck. Usualy hapens in cold whether when the hand brake has been applied for a long time. After the car is driven for a while the "stuck" looses itself. don't apply the handbrake in cold whether when car stationary for long time or have a garage to look into it and mayby clean the hydravliks. i t my need new brakes fluid as well.

Try a bit of Copperslip on the back of the pads when you put them in

[moptisam2]

Without me boring you all with my opinion of main dealers (and in particular Volkswagen in Plymouth, who couldn't sort out a problem with the brakes on my Golf that my local family garage found and fixed in 20 minutes!) I would say try to find a local garage with a good reputation that doesn't just put the car on a computer but actually looks for the fault!