I have a 1999 Chevt Tahoe 5.7L Vortec 4x4. When in stop and go traffic with the a/c on my truck sounds like a leaf blower or a transfer truck when I take off. If I give it half throttle or so it will go away when I get over 35 or so. Doesn't do it at highway speeds at all. If I do alot of driving in stop and go traffic it gets really bad and the truck has no power at all, and I have to cut off the a/c and drive without it and in a few mins of driving the sound will go away. I am lost on this one and it is driving me crazy! Any ideas?