Scraping noise from steering

[MDA123]

I have a 2010 B6 Passat 2.0 TDI which has done just 38000 miles and there is a scraping noise coming from the steering. I've jacked the car up and spun each wheel in turn - no noise. I've jacked up both front wheels together and turned to the left and right turning each wheel - no noise. I've removed each wheel and examined the discs, brake pads, back plates, linkages, suspensions arms, boots, gaitors and cannot find any evidence of scraping or metallic noise; pads are only half worn and there are no stones or anything which might be touching the discs.
I can only hear this scraping noise with the window open whilst actually driving and turning slowly to the left or right - it makes no difference if I brake gently so I guess this confirms there's nothing wrong with the brake pads and it is not on full lock.
Any clues please?

[RichardSEL]

Manual or auto?
From your description this scraping noise only occurs when in drive? What about when in freewheel forward, in neutral?
What about when in reverse both in movement in reverse gear, and freewheel movement in reverse?

[Doctle Odd]

Can you post a video or sound clip?

[MDA123]

I doubt if I can post a video or sound clip (but I'll see what I can do with my camera) but it is a manual and there is still some noise when freewheeling in neutral - but, when I can find somewhere suitable, I will check this when reversing. What sort of noise would dry bearings make or maybe a problem with the steering rack/drive shaft? There is no leakage anywhere, no splits in rubber boots, steering is perfectly straight and the suspension seems fine (no rattles). I cannot detect the noise at speed but I don't turn corners at speed so I don't know what would happen. For sure though, the noise is getting worse.

[sar02]

Is it possible you have a faulty ball joint?, might only show under load.

[Flash2]

Maybe a small stone has got jammed in one of the brake calipers or the carriers. That can cause intermittently sounds like your pads are completely worn down to the metal or sometimes a higher pitched screech.
It would be worth removing the wheels and taking a look in behind the discs before getting into anything more complicated.

Jim.

[MDA123]

Indeed that was my thought. I've removed the wheels and examined the brake pads (only half worn), back plates and discs and cannot find anything wrong, although I did not remove the pads or the calipers. Anyway, I couldn't detect any noise when turning the wheels by hand but of course the fronts will only turn slowly (FWD). I thought about jacking the front up and running the engine but I can dismiss that as I can hear this noise when coasting in neutral or in fact having switched the engine off and freewheeling to a halt (pressing or releasing the brakes made no difference). The noise is most pronounced when just beginning to turn left or right (not on full lock) but I can now even hear it when gliding to a halt (engine off) going in a straight line. I can hear a distinct scraping noise with almost a 'groaning' type noise as I turn the wheel. I suspect it is getting worse but I haven't yet been able to hear it when reversing.

[micheal balbrig]

The brake back plate, could it be close enough to the disc to to contact same if bearing had slight movement

[MDA123]

There's clear air behind the brake back plate so I can't see how it could be touching the disc - also no marks on the disc either side so it can't be a stone or something caught behind it.

[Flash2]

I've had cars on on the up on the ramp with the brake caliper removed and still struggled to find the tiny stone that was wedged in and causing the noise. There must be something about the geometry of the brakes on VWs that causes this because this seems to happen a lot.

Found this clip on youtube : Stone in Brake - YouTube (https://www.youtube.com/watch?v=JHwhQpquEdA)

[MDA123]

I guess I'll have to get the calipers off and see if there is anything wedged in there but there are no score marks on the discs and I couldn't detect any noise when jacked up and turning the wheels by hand. The scratchy noise does sound like a trapped stone but why the scraping or groaning noise as I steer left or right? Could it be a totally dry CV joint? The rubber isn't split and there is no leakage.

[Doctle Odd]

Is there PS fluid in it? Is the aux belt tensioner tight?

[Flash2]

The scratchy noise does sound like a trapped stone but why the scraping or groaning noise as I steer left or right?

Because there is always slight play in the wheel bearings and that causes the brake disc to move slightly when cornering.

[MDA123]

Is there PS fluid in it? Is the aux belt tensioner tight?

No PS fluid - it's electric.

[Doctle Odd]

Ah I see.

[vespa]

I suspect the backplate is touching under the stress of turning and not showing any marking as yet. You could try changing the pads in case they are the cause.

[MDA123]

I've just done over 200 hundred miles to Gatwick Airport and back so it can't be rust and there's nothing rattling or shaking but when I've got the time I will remove the pads and check behind the calipers. It's just strange that from about a month or so ago this noise started just as I begin to turn the steering in either direction. I'll see if I can record the sound because it's not exactly like metal to metal making contact more a low scraping/rumbly noise.

[MDA123]

Update
I have not yet had the calipers off or the pads out but I have had a serious problem: no clutch. Yesterday the car wouldn't re-start - pressing the key did nothing; I noticed the message screen said to press the clutch (you always have to press the clutch to start) but I was already pressing it - so I released it and pressed again and the car started. A little later that evening it started but then no gears - nothing from the clutch pedal, pumped it up and down but I couldn't select a gear. I have to admit I was just a little panicky but eventually realised that the pedal was actually stuck half way down so I manually lifted it up. That worked and my clutch pressure was back and the car was then drivable. Today, not only does it drive okay (touch wood) but the scraping/rumbly noise appears to have gone. I'm not exactly confident that all is well as maybe I have a problem with the clutch and presumably DMF assembly?

[DMitch16]

That said mine had a strange rumbling / scraping noise when freewheeling - turned out that the last tyre place had buttressed the hub threads with their stupid air wrench torque set too high!! The right wheel was not evenly tight on the hub even though the bolts themselves felt pretty tight and there was no shudder or other signs of unbalance. Took the bolts which were fine and still intact out and used copper ease on the threads. Counted the revolutions on each bolt from start to tight and all had same number to the point where they reached the right torque - no more noise!! Will change hubs eventually as they are only £40 each but tyres have a year left in them still and hopefully wheels won't need to come off until then.

You should not use any substances on wheel bolts as it can lead to stud overtorquing and with alloys serious cracking especially if you hit a few road bumps or pot holes. I used the copper ease just to get the bolts to fully screw into the hub then cleaned off the copper ease from the bolts and holes.

[RichardSEL]

What's the "right torque"? When I changed to Kumho's a few months back used a backstreet 'n gutter place to change from mail order delivery. At £10 a corner with balance. They used an air wrench too (as well as using the same old valves...) You've got me wondering, so might as well check. What size rims yours? Mine's 16"

[DMitch16]

Some say between 80 Nms and 120 Nms depending on the nuts / bolts and wheel composition but 80Nms is a little low. Mine are 17" stock 5 spoke Sport alloys and 120Nm is the recommended torque (they actually get tighter on the car but this may be due to the buttressed threads). A very good tyre fitter friend of mine says 110 to 120 Nms is right for most modern wheels and although he uses an air wrench to save time getting them on he slackens off each bolt slightly and uses a torque wrench to apply the final pressure of 120 Nms. The trouble is that some fitters can't be bothered with the final part and have their wrenches set well over 150 Nms so no-one can come back to them if the wheel comes loose! Cross threading is also an issue as an air wrench would simply ram the bolt into the hub across the normal thread grooves without anyone noticing (until you try to take the wheel off!).

All current VWs have an alloy wheel bolt recommended torque of 120Nm with the exception of the Tiguan and Sharan 2010 on (140), Sharan and Multivan to 2003 (170) and Toureg, T5 and Amarok (180).

[Doctle Odd]

The correct torque is 110 nm or 81 lbs, Those rattle guns are always set too high and I have often seen guys starting the bolts with them, this is a stupid thing to do