gmanhouser

I've owned a 2001 Tahoe since 2009, and we love it. I replaced the entire AC system two years ago, and it has run great. However, a week ago I had to replaced the original radiator, and immediately after which I began hearing a new and very loud jackhammer-type noise, but only in low RPMs. After several times hearing it, I pulled over but couldn't see anything. I tried emulating gear progression while in park, when "snap" something broke. It was the AC belt, snapped in half, not worn or otherwise damaged. After replacing the belt, the noise remained, but only occurring between 1.5-2.0 RPMs. I soon determined the AC tensioner would vibrate very violently, causing the jackhammer noise. I replaced it (twice, with two different brands), but the noise still crops up. The noise ONLY occurs when the AC is on. I don't want to automatically just replace the compressor, but does anyone have any ideas for why I'm having this noise? Could my new belt be too loose??