I have a 2001 A4 1.8T AWM Quattro Avant with ESP

The oil temp gauge is intermittent, the ABS light flickers (it's not on or blinking), the red break light flashes and the mph guage jumps while the car is not moving. The RPM gauge and everything else is fine. The engine also runs a little ruff when the mph gauge is jumping. No check engine light.

When the engine is cold and I start it up, no symptoms on the dash. When I warm it up and then start driving it, the break light comes on and all the other stuff mentioned start freaking as well. The symptoms continue after car is parked after it's warmed up. Shut car off while warm, start up while warm, symptoms continue.

I sent the instrument cluster in for repair, they fixed the LCD screen because it was bad but they said everything else in the cluster checked out fine, gauges and indicator lights work as expected.

Next I suspected ABS issue. Disconnected the ABS modulator/pump, no change in symptoms. Disconnected the ABS computer under the rear seat, no change in symptoms.

I can't find anything on any forums anywhere that is similar to my symptoms.

Help me solve this wonder piece of German engineering....

 

Wow.....180+ views and not a single comment on this one. Seems like something most Audi owners would eventually experience with this particular chassis type.

There is a grounding stud on the fire wall, right under where the coolant expansion tank is. Remove the expansion tank and it will be right there in your face. All sorts of brown wires running to it and the wires will be loose.

Tighten it and all your intermittent issues will go away.

That lug has effect on the mph/speedo gauge, oil temp gauge, abs light, break light, I'm also suspecting low oil temp sensing (sometimes my low oil light would come on, even though I have good pressure and a new oil pressure sensor).

I hope this post helps people before they go swapping out ABS parts and sensors, etc...