scraping noise

[faker]

Anyone have any idea why when I corner hardish left there's a scraping - rubbing sound? There are absolutely no visible signs of contact with wheels or suspension parts. Really confusing...

[RicardoM]

How many turns (or better degrees) does the steering wheel from wheels straight to full left and full right respectively? Try to be very accurate.

[faker]

Roughly a quarter to a half turn is all that's required to make the noise.

Edited 24 March, 2017 by faker

[faker]

And only left turn

[RicardoM]

I asked something else. It was about the symmetry of the steering. Anyways, if there is indeed no obvious visible signs of scraping, I would look at front brakes. The splash cover might be deformed or the sliding pins of the caliper might be seized.

 

It would help (as usual) to know the history of the issue. For some reason nobody feels useful to describe how the issue started, what related repairs have been done lately, what is the most suspect area, what has been done to diagnose the issue, etc. We are left guessing based on very little information...

Edited 25 March, 2017 by RicardoM

[faker]

Well.... 1999 skoda felicia. 50k, I'm the third owner and have owned it for a year. Noise just came in to it all of a sudden. Extensive checks carried out. Dust cover on the front brakes not making contact on cornering, tyres not making contact with arches or mud flaps (that's the sort of noise I'm hearing), no rubbing or contact on full lock, no seized or worn brake components. As I've said, between a quarter turn to a half turn to the left side only, there is a scraping noise, with absolutely no visible signs of contact at all. I was beginning to think it could be something to do with the diff!

[faker]

Oh. Steering symmetry. Alignment is perfect with steering wheel straight and true. 

[faker]

Sound is coming from offside (drivers - right hand corner).

[RicardoM]

Did you check if the front wheels are proper torqued? 

Is the noise happening at any speed?

What makes you think the diff has anything to do with the rubbing noise?

[faker]

Wheels are torqued. Hub is tight. One and a half turns from centre to full lock, left and right. 

 

I can't explain it!

 

Don't know why I thought it was the diff. I can't find and faults with the front right wheel assembly...

[mikefelicia]

Take it to a  Skoda dealer for a MOT and tell them the problem.

[faker]

Doesn't work like that in Northern Ireland. MOT centres are run by the government and staffed by civil servants. MOT testing facility only.

 

Not to worry. I'll struggle on! It's been doing it for a few months now... not getting any better or worse!

[RicardoM]

Again, is the noise happening at any speed?

[faker]

Only under hard cornering to the left. Relative to the cornering force rather than speed.

[RicardoM]

I think I know where this topic is heading but let's persevere...

 

Is the front suspension modified in any way relative to the stock version?

What kind of tyres on the front? Any deformity of the rims? Any lump on the tyre? What happens if you switch the front wheels?

Did you hit a curb, a hole in the road or any other obstacle?

Did the noise start to occur after another person drove your car and possibly "forgot" to tell you?

Try to remember any event that might be linked with the noise. This kind of things don't just start occurring out of the blue.

[faker]

Had Silverstone tyres on the front until two weeks ago. Rear tyres were old and very dozed and cracked. Swapped the Silverstones to the rear and fitted two new Nordex tyres on the fronts. All rims are true. Brand new tyres now up front. Good tyres on rear. 

 

This noise is a bit of a head scratcher. Front discs are not new by any means, but still in good shape with recent pads. 

 

No bearing noise or free play.

 

Standard ride height with standard components. 

 

I think you may be right Ricardo. Thanks for all your input here. I can't find the source myself, which led me to suspect that something may be wrong with the drive train  (when I previously mentioned the diff). I was thinking that with worn bushings, strut tops etc, that the components may be flexing or moving more than normal, allowing say the hub assembly and driveshaft to press against the box and diff.... I haven't a clue what's going on. All I know is that when I steer hard left there's a noise from under the car, that I can't find, and all the components look good! 

 

 

Edited 26 March, 2017 by faker

[faker]

wee car really is in good shape. Drives great, will probably need a clutch soon, and could do with a couple of drop links, but other than that it's good. 

 

I'm not planning on rebuilding the thing though!

 

Edited 26 March, 2017 by faker

[RicardoM]

faker

Try to concentrate and answer all my questions to get to the bottom of it.

 

Now, it's almost a head scratcher indeed if you are 100% sure there are no visible signs of rubbing. But let me ask you this: how did you check the car underneath? Did you raise the car on a ramp and used a bright workshop lamp? Did you have access to a visiting pit and used a bright workshop lamp? Did you raise the front of the car on jack stands and used a bright workshop lamp? Or did you just raise each side of the car with the jack of the car and had a peek underneath? I think you understand where I'm going.

 

If you had best access and plenty of light, there are only a few possible issues left such as:

• the brake disk develops a 'ridge' from the brake pads both towards its center and towards its exterior. It is common practice to file the ridges before installing new brake pads. Check and act accordingly.
• you failed to mention if the noise started to occur after changing the brake pads or after changing the tyres.
• you didn't swap front tyres (left <-> right) as requested to see what happens

For a transmission / diff noise to occur suddenly, a big shock is needed. You didn't mention if one of you had a close encounter with a hole or a curb.

[faker]

Hi Ricardo 

 

I'd the felicia up on a trolley jack and stands.

I was right underneath it.

 

Noise started months ago, long before new pads were fitted, or the brand new tyres... (and the reason these changes have been made).

 

I can raise the car up and take photos if you wish, there are no signs of obvious contact anywhere..

 

Noise literally started all of a sudden. Quite some time ago. 

 

No sudden impact in my ownership  (other than a minor clout to the sump over some rough ground last year. Little dent to metal sump, nothing more).

[RicardoM]

Well then, you have two things to try and check according to my previous message.

[faker]

Cheers Ricardo 

[RicardoM]

Extra job: check if all bolts and nuts related to suspension, steering, and brakes are torqued properly. A rubbing noise should leave a mark unless it is inside the brake caliper or the rubber boots of the CV axle(s).

 

PS

In mystery noise cases like yours, I mount a miniature video camera in a strategic point under the car and go for a spin to recreate the noise. Maybe you can do that too or at least record a video from inside the car to let us hear the noise too. Upload the video on YouTube or similar and share the link to it.

[faker]

Hi Ricardo 

 

I regularly use a dash camera in my octavia. I could mount it in the felicia and see if it can pick up the sound. Leave it with me.

 

 

[RicardoM]

Did you find the cause of the mystery noise?

[faker]

Hi Ricardo. Still no wiser at this stage... no idea what is causing the noise. Car still drives great and it doesn't hinder it at all...