Car a/c question help?

when i first bought my 2000 firebird, whenever i ran the a/c there was very large amounts of water that pooled up under the vehicle. i knew a little water was normal, not a pool the size of my car. now no water comes out at all and there even is a strange metallic sound coming from the compressor. my mechanic suggested adjusting the a/c clutch for the sound. any other suggestions?