On my car. I literally have a cluster In pieces on my desk that I was repairing. The old empty was the 1/8th of a tank marker.
Mine has done the same thing...171K on mine. Not sure it there is a way to recalibrate it or whether the fault lies in the float in the tank. It has been getting progressively worse to...to the point that it showed over 1/2 tank and I actually ran out of fuel. I went 490 miles on that tank I later discovered though...haha.
Check the gauge against the "miles to empty" in the central display if they agree it's the sender(s) if not use VAG.com to check the gauge.
2 senders in a quattro.
Dirty senders is pretty common, you can clean them with a pink eraser and contact cleaner . Replace the tank seals otherwise they will leak. I cleaned mine a year ago any they are still OK.
Oh yea I'm more than aware it's the cluster... The vagcom tests prove it.
I have an extra cluster that the tach doesn't work and the oil light flashes, but everything else is perfect. I removed the gas gauge motor from the good cluster and plan to install it into my current cluster. I'm gonna line it up with the vag-com tests- or I hope it all works out that way. I've read it could be the firmware for the cluster as well.
Process part one- the good cluster stripped down:
Last edited by DougLoBue; 04-26-2012 at 11:02 PM.
Doug, let me know if that works out for you - I (and every other TT owner ) have the same issue, and also a spare cluster.