bizarre noise

[Simon Allcorn]

Just took my 92 90q 2.8 V6 on a 100 miles drive and as I parked it and
stopped the engine there was the sound of *something* spinning down from
what sounds like very high rpm - the closet thing I can compare it to is a
turbo (a previous car was a SAAB 900 Turbo) spinning down after a run ( or
come to think of it a plane shutting the main engines down after coming to
rest). Anyway it stopped about 3 seconds after the crank has stopped turning
and I haven't a clue what it could be. The engine has aircon that dosen't
work (as I found out yesterday) but we where using it on and off during the
drive. Not sure how relevant the aircon is but I know next to nothing about
it.

On another note I'm using VAG-COM to get the trouble codes from the car -
555 - (O2 sensors - surprise !) but looking in the Bentley it suggests
looking at block 10 to get the output voltage from the sensors, but VAG-COM
says that blocks 1 - 25 are not available - does this mean that I can not
measure the output voltage of the O2 sensors ? (Engine is a 1992 AHH type)


Simon