srmurrayut

I had same issue with my 2005 A6 3.2Q at about 19K miles. I had never seen this before in 40 years of cars so took to dealer and read forums. Found that it is quite common. Got a bottle of fluid at the dealer - VW/Audi Petosin, cost about $20, topped of fluid and groan is gone. I suppose I could have found a cheaper local source, but this bottle will likely last longer than the car - so what!

MP4.2+6.0

Check the Audi fuid capacity chart if you want the official word. Available in any Bentley on line manual; I looked at it as recently as yesterday. Or, go to any Audi dealer parts counter.

The mineral stuff has not been used in new cars for 17 years now. Having owned a C3 (Audi 5000/100) pre-changeover, I can confirm first hand the nightmare those systems were with the prior fluid--blown steering racks were common on those cars. A thousand dollars + back then to have it replaced. Yes, as I said in the post, my car is marked wrong too.

Once again, going all the way back to the original post, from experience the old mineral based oil can cause it to make noise when cold. That and the wear factor are presumably among the reasons Audi got away from it.

schnellmb

it's getting out of the system somehow.

KevinGary

Dealer just replaced lines and clamps for power steering in my 2005 A6 4.2, 36k miles

Igor2003

If it is green it'smineral, if it's not green - it's synth.