need some help - coolant leak

[drexplode]

i accidently posted this in the B5 S4 forum...

Hey guys, I just got home about 20 mins ago and then poke my head into the garage and found a small coolant leak on the ground. Open up the reservoir and it gushes out.

Checked the following:
-coolant reservoir
-coolant hoses to radiator
-radiator

I cant think of another place where it would be coming from. It appears the drips are coming from somewhere in the middle of the engine (not the back, not the front). My mechanic thought it might be the coolant temp sensor...?

What are your thoughts???

Car = 1999 A4 2.8 w/ 117k miles.

pics:

[offroader1006]

turbo line

[drexplode]

haha its the 2.8 V6, i wish i had a turbo :-)

when the car is on level ground w/ belly pan off and i open the reservoir cap the fluid gushes out of the passenger side.

T-flange on the back of the engine? Is there a DIY?

[drexplode]

is there a after-run / auxiliary pump on the 2.8? if so, where is it located?

[drexplode]

Audi doctor says it is the rear pipe that connects to the aux water pump. Labor + parts = 2 benjis. Phew, i thought it was a head gasket.

[w4xm4n]

Having this same issue at the moment. Did you ever find a DIY on this? I'm going through the bently book now, and very well may make one...

[Mad Cow]

The aux pump is tucked way in there, under the passenger side head near the AC compressor. I didn't even know there was one until I tore my motor down, that's how hidden it is.