Question - Can Warped Discs Cause Vibration Noise whilst NOT Braking?

[fran-s3]

Would appreciate your help guys - last gremlin am trying to solve!

Problem:

Vibration noise well more of a slight droning really at 40mph and stays until around 44mph and goes. Random?! Also when braking from 40mph + I get bad vibration from my steering wheel. Also if travelling at 80mph I get a slight constant vibration through my steering wheel as well whilst not braking......

Garage Solution:

Been advised today my front brake discs are warped by a VW specialist. That would explain the judder whilst braking but could it also be making the whirring noise at 40mph? I've had my wheels balanced which helped but didn't cure it - was even worse before.

Suspension wise I've had 2 new shocks 8months ago so know it can't really be them. What's frustrating is they're black diamond grooved discs that are only 1.5 years old - should these be lasting longer? They certainly weren't cheap! Anyone else's discs lasted longer? I'm not an aggresive braker either.

The garage advised it could be the discs that are warped causing the vibration noises to... Only other things I can think of are wheel bearing <although this should be constant apparently at all speeds?> or drive shaft? But garage is saying isn't suspension related. Should I get a second opinion?

Any thoughts or advice greatly appreciated.

 

[jojo]

My experience with warped disks on an S3 is vibration through the steering and brake pedal when braking, otherwise, it would just drive normally. No sounds.

 

[jojo]

Oh, and just to add, I also overheated a set of brake pads which left a mark on my brake disks, this caused an aeroplane type of sound under braking until it was worn away, and it actually felt like warped brake disks at the time.

 

[aragorn]

I'd change the disks and see what happens, they need done anyway by the sounds of it.

 

[steve bain]

no. shouldn't do it.

look at buckled wheels! they may have balanced them but buckles will always cause vibration and some wheel guys just follow the computer!

 

[a3tdi2001]

Could well be. I had "warped" discs which were making a fairly loud modulating grinding sound around 30mph. Didn't think it could be the discs until I renewed the brakes and greased them up: noise no more. Does a light drag of the brakes change the sound?
This might be worth a read and ties in with the post by jojo: StopTech : Balanced Brake Upgrades

 

[fran-s3]

Thanks Guys!

Arghhh what to do lol! Yeah I didn't think it would effect any noises if the brakes aren't applied but interesting what a3tdi2001 said. Maybe I should bite the bullet and do them and see what happens. How long should a brake disc typically last for?

Buckled wheels interesting point actually - not taken any bangs on the wheels and I did swap them front to back interesting and still the same. Is it easy to spot a buckled wheel? Just to add a light dab on the brakes doesn't change the sound a3tdi2001 - it still makes the same rumbly sound at 40mph... Strange one!

 

[a3tdi2001]

Did the garage check the run-out of the discs?

 

[TwinCamMan]

You will spot a buckled wheel easy enough, put the wheel you are looking at in the air (axle stand) and get someone to give the wheel a good hard spin while you watch the rim. If it's going to be buckled it's probably going to be on the inside, hence getting someone else to spin it for you. Or if you have a balancer, or access to one, you'll spot it straight away on that.

But as was said if your discs are shot you'll have to replace them anyway. But if the sound you have is a rumbly one it sound like the start of a wheel bearing on the way out, can you work out which wheel it's coming from?

 

[s3dave]

If the run out of the disc is really bad it can cause vibrations /noise as it is trying to push the piston back from the pads on each revolution

 

[fran-s3]

No they didn't - I didn't realise you could do that actually? What does that mean - do you need a machine to do that?

Ok cheers TwinCamMan - I had them balanced actually and I watched my mate balance them on his machine when he took them off - so presumably he would of spotted if it was buckled. Only one was slightly out... Did improve it slightly. No I can't workout which side it's coming from - to be honest it doesn't sound like it's coming from a specific sound to be honest. Just feel vibration through the steering wheel...

Yeah your right chaps I need discs and pads anyway... Will go for standard Pagid or Mintex discs (not sure which are best) and I may as well go for some DS2500's pads while I'm at it.... Certainly can't justify black diamonds anymore after this experience.

Interesting S3Dave... Didn't realise that maybe that's what it could be doing? Hmmm would explain it.

 

[rraghvani]

If wheel bearings were slightly knackered, then they would make a grinding noise when turning fully either left or right. If it was proper knackered, then you would be able to feel play while moving the wheel (front wheels jacked up) or slight grinding noise while turning them by hand.

If the brake disc were warped, then the vibration will get worse while braking and the car will pull in direction of wheel being braked most; you will get excessive heat coming from the wheel; you will get a pulsating feel though the brake pedal too.

Sometimes brake pads get stuck on the brake callipers if they are not cleaned and greased properly.

If the wheel is not aligned properly (check tyre tread is not worn), or balanced (check wheel has weight balancers, most wheels do), or tyre may have a bulge, then this can cause the steering wheel to vibrate left and right too.

I had similar problems about a month ago after fitting new Pagid brake disc; I had frown my diamond black combi (grooved & drilled) as cracks were appearing after two years of use; I was slightly lazy and didn&#8217;t properly clean the wheel hub and brake callipers. Had massive vibrations after coming off a motorway, and I was fighting with the steering wheel to keep the car straight. Anyway, one weekend, just spent some time doing the job properly, cleaned wheel hubs, callipers and even brake pads with a wire brush, and had greased the section where the brake pads slide on. The car runs nicely now without any viberations, apart from the knocking feeling that comes through the steering wheel as most of by bushes have worn out.

 

[fran-s3]

Well after having a word with Black Diamond who turned out to be quite helpful, I've been offered a new set at a trade price. Although they still work out at almost double the cost of standard Pagid discs would be from GSF - unsure whether to bite the bullet still. They were out of warranty as it's normally 12months. Hmm... Only value I can think of is resale value in the furture if someone see's black diamond discs they may want the car more.

 

[A3Tom]

Before you start buying stuff mate I'd take the discs and pads off, clean it all and refit with a good amount of copper slip etc etc.

 

[Sandip]

Check the wear on the tyres is even, if a tyre has been running slightly down on pressure it may have a flat spot on it which will make a sound as though you have a worn bearing

 

[fran-s3]

Thanks for the advice guys... Yeah had new tyres recently F1 GSD3's so they're good. Do wheels bearing make a sounds constantly in everyones experiece? My noise seems to be at 40mph then goes at say 43... Random?! Then steering vibrates on motorway at higher speeds slightly. Random.

 

[jojo]

Thanks for the advice guys... Yeah had new tyres recently F1 GSD3's so they're good. Do wheels bearing make a sounds constantly in everyones experiece? My noise seems to be at 40mph then goes at say 43... Random?! Then steering vibrates on motorway at higher speeds slightly. Random.

Knackered wheel bearings, in my experience, is a constant drone which changes sound with the car's speed. If you are doing 40mph, and there's a sound, try coasting(pressing the clutch down) to see if the sound is still there, if it is, then it could well be wheel bearings.

 

[fran-s3]

Guys just an update and another good result. Dropped the car of to Ed @ APS in Brackley (APS | Independent Specialist | Audi | Volkswagen | Porsche) who diagnosed and fixed the rumble! Turned out it was actually the driver side wheel bearing! Replaced (apparently it practically fell out as it was so bad - and was knackered. Usually they're pressed out by force!) So again another mystery solved, great customer service by Ed's team as usual and they know they're stuff. Hope this helps anyone else with a similar issue. Hope my suspension gremlins are now over for the time being!

 

[Westy]

glad you got it sorted mate.