I have a 2004 S10 pickup with ~2900 miles on it. I noticed during the last
200 miles or so a funny noise that accompanies shifting.
I would describe it as a whistling noise, like wind through reeds... that
almost has a ringing sound with it. It seems to happen when the torque
converter unlocks and goes away shortly after shifting up. Nothing feels
wrong at all. Also, it doesn't happen until everything is warmed up a bit,
maybe 10-20 minutes of driving.
I'm going to stop by the dealer and have a service guy drive around with me
for a listen, but I thought it would be worth asking here as well.