Square wheel sensation

[Redzer]

i noticed a strange thing that happens occasionally with my A6 when slowing to a stop.

If the car is rolling very slowly with the clutch in, the engine running and without touching the brakes you can feel a sensation that can best be described as being like you had one square or 50 pence shaped wheel fitted on the car or the abs was kicking in at a very slow rate.

Its not the wheels or the road surface causing it, just curious if anyone else had ever noticed this and had an idea what it might be.

[djl78]

Sounds like warped brake discs to me.I have it on my polo and find it really annoying but am too tight to buy new discs.
regards
djl

[Redzer]

The brakes are ok and theres nothing noticeable under braking,

i presume if the discs were warped you could do a quick check by jacking up the car, rotating the wheel by hand and checking if the pads were catching at some point or if the wheel rotated freely.
must have a look at them and see.

[moggies]

You could simply have an out of shape tyre. I would have thought it to be a rear, as if it was front the steering wheel would rock slightly as you roll along. I would jack up the car and spin each wheel and look along the line of the tyre.

[radix]

I never noticed that before, but maybe its possible that it would be a flywheel/clutch thing, that it only does it at certain rps (low in this case)?
What mileage is on it, and did u have to do the flywheel or clutch before!?
On that point, something i've noticed with mine:
When you go to move off after starting the car, you'll hear a click, (and you'll actually feel it on the clutch pedal) when you let out the clutch for the first time after the car has been started. It wont do it again no matter how many times you let the clutch in or out, unless you switch off the car and start it again! Weird I know, but i'm guessing it does it for a reason at the fact that it doesn't do it every time, that its just the first time after the car has been started!
We also have a 00 first edition A6 1.9TDI 115bhp and it doesn't do it at all on that, so i'm wondering is it something with the SE?

[paul b]

i noticed a strange thing that happens occasionally with my A6 when slowing to a stop.

If the car is rolling very slowly with the clutch in, the engine running and without touching the brakes you can feel a sensation that can best be described as being like you had one square or 50 pence shaped wheel fitted on the car or the abs was kicking in at a very slow rate.

Its not the wheels or the road surface causing it, just curious if anyone else had ever noticed this and had an idea what it might be.

Possibly the inner (obviously not outer!) constant velocity joint may have seized up.

Only way of knowing is to take them off and give them a wiggling.

Had this a long time ago on a VW Scirocco, gave it a very weird sensation.

Just possibly though, but its worth checking.

[Redzer]

Thanks for the replies guys, its not really a big deal just curious if anyone else had noticed it.

i havent noticed that click you mention either Radix.

The car has 63k miles on it and hasnt had the flywheel changed.
Ive had a problem with uneven running in a very specific rev range for a long time now so i'm paying attention to every little niggle with the car hoping i'll stumble across a related problem that might help the uneven running problem too.

Once i get a dry day where i have a few hours to myself i intend to have a poke around the car and see what i can find.

[NickPicks]

I had this feeling once on my old Hillman Imp. It turned out to be a bulge in the tread of one of the rear tyres. It felt a bit bumpy at 30 mph, but got a lot worse as the car got faster!