Here is the Audi A4 B6 1.8T 2002 Avant
It happens at COLD START
You can hear that some High Pitch repeating noise
Most obvious starts at 00:17 and onwards

Weeeee...Wommmmm....

Very High pitch

Anyone can advise ?

Thanks

 

mine did the same thing until i changed timing belt and water pump.

 

does this HVAC kick on when the noise comes on? Try Turning off HVAC and see if it still happens. Could be AC compressor. Could be water pump if you havent changed it and you have over 75k.