DWPC

The single engine issue I had on my Audi was the aux cooling pump for the water-cooled turbos. I haven't found any mechanical details or diagrams for the V8 turbo engine that say if the turbos are w/c or not.

bigbuzuki

The 955 turbos are water cooled.
Don't know about the Direct Fuel Injection V8.

DWPC

955 is through '06 (eg '07), right?

bigbuzuki

Correct.

touareg

How can you tell the pump is running. Is it only during engine on or after you park.

XR4Tim

From the General Servicing & Repair book:
"To cool the turbochargers while the engine is not running, the electric coolant circulation pump, which is installed behind the wheel house cover at the left front, can be switched on. The electric coolant circulation pump is switched on as needed in run-on operation together with the electric cooling fans by the DME control module."

touareg

Cool, thanks. Used to cars that have it always running after driving for a bit, but I never hear it on mine. Just metal pinging from material contraction and air compressor noises.

DWPC

When I drove an Audi 2.7T, the aux cooling pump ran frequently after parking in the garage. I've never heard it run in my CTT; even in an AZ summer.

JAGMAN1

I can hear it on mine. It has a low hum that is audible for a minute or two after the engine is turned off

touareg

I always assumed that was the air compressor, since typically my car would settle at the same time.