A8 Auto rolls backwards down hills

[A8Sport]

Just come to sell my car and the buyer stopped on a steep hill (1:8ish). He then took his foot off the brake and the car started to roll backwards. This suprised me as I had never noticed this during normal driving.

It holds fine at 900rpm but at tickover of about 750-800rpm it rolls backwards. Not just a little bit but continuosly until you hit the brakes or throttle.

a) Is this serious?
b) What might be causing it?
c) Is it something I can fix cheaply or do I just raise the engine idle to 900rpm?

[Gerbil]

Not sure what model you have but my 05 has an automatic "hand brake" that kicks in on any steep gradient? The red light on the button glows and you can normally hear the servo operate.

It sounds as though you need to get the tick over checked and the hand brake, unless your model is significantly different to my 05.

Good luck

[oldgrowler]

i would suggest you get the tickover checked as it should be 850rpm as i found out the other day as i had local audi check mine as i thought it was running high but they tell me thats the best rpm for it

[A8Sport]

Thanks guys. Garage adjusted it and everything is fine now. It sailed through it's MOT too which was nice. Now I just need to sell it.