on my old 95 monte carlo with the 3.4 L engine , after I had one of the power steering lines replaced , I noticed a similar noise , usually on increase in engine rpm made louder when turning.
I had been using gm ps fluid and lucas ps stop leak before , but now the pump was refiled with standard atf III , so either the fluid or the new hose section was the cause. regardless It worked fine until I stopped driving that car not too long ago.
what color is your PS fluid ? if its red most likely ATF III trans fluid, the GM stuff is more of a light almost clear oil.
