Tracking, steering wheel and the ESP light

[JGP]

Got the issue with the ESP light coming on after about 20 mins on a motorway. The steering wheel has always been about 8° of centre to the right. Conclusion was that if car tracking was aligned with steering wheel straight the ESP would be cured.
So far so logical.
Repeated attempts at tracking with laser devices. All four wheels. Up to maybe a dozen attempts. Every time it goes for a test drive the tracking has changed by a mm or two or sometimes more and the steering wheel always seems to fall back into the 8° offset. Almost as if the wheels are mounted on loose hubs.

Absolutely baffled. The point being that even if it was a cut and shut job (God I hope that is is not) then it is likely any incorrect readings would be constant and unrepairable. This seems to involve movement somewhere but everything seems tight. Track rod ends have some movement by design but have new ones so should be well within tolerances.

It is an A4 tdi Quattro Sport 130 if that makes any difference
All those involved are at a loss.
Any ideas?

[abyrne153]

I had this as well on my 2.5 quattro sport after the guy doing the alignment was careless and left the steering off centre. The fault is caused by the steering angle sensor being unable to pick up a signal and like yours it only showed up on motorways. The fault was easily cured on mine as I took it back and made them set the wheel straight and do the 4 wheel alignment again. I am totally at a loss as to how yours is going off after being checked so often. Perhaps the alignment equipment needs calibrated ? Maybe you should try another garage if you haven't already !

[JGP]

That is the problem. This is the second place I have tried. Both places are pretty good and know their stuff. The second place is also a racing specialist so are hot on suspension - which kind of makes it even more puzzling.
Hopefully it will be something so obvious that everyone has overlooked it and we will get a collective "of course thats it"

In the meantime trying a new set of wheels to see whether that is where the problem lies.

[Alan02]

If you are happy that alignment is correct. Re-align the steering wheel.

[trioptics130]

i have had audi code in cruise for me this morning and because they had to take off the slipring and because in the past i clouted a stone knocking the wheel alignment out the esp light wouldnt reset, made the comment to either re-center the wheel or re-track the road wheels should sort it apparantly that wont do it, the slipring has to be recentered and would take half an hour. Half an hour later job done so if i were you let audi sort it for about the same money it would cost for the tracking to be done

[JGP]

Thanks to all for replies. I will let you know how I get on. Hopefully nothing major.

JG

[abyrne153]

Its unlikely but you could try to swap the tyres around just in case there is a dodgy tyre or maybe a damaged rim causing this ? It wouldn't cost anything and it may be worth trying.

[Dazzler01]

Had the same thing happen on a subaru imprezza once and it was the steering rack bolts that had worked loose,baffled just about everyone before it was found(by accident)its an easy check to do-you may be suprised !!!!!!!!

[JGP]

Not quite the steering arm but the front suspension arm. The bush had worn so much that it was jamming itself from side to side and not showing any movement even with a crow bar - of course road travel was enough to move it. Only spotted through someone being under the car at the right time. £60 part fitted and bingo Alles ist gut.

Thanks to all for help