Hello everyone, I am a new poster here, and would like to share how I solved the problem with the Intex 2500 g.p.h. cavitating (rattling) when using the skimmer basket attachment, what is happening, is the pump is trying to push more water through the filter than it is able to pull in through the suction line, and the problem is not with the pump but is with the blue skimmer hose screw on adapter, it is restricting the volume of water needed for the pump to work properly, (imagine holding your hand over the suction end of a vacuum cleaner and reducing the amount of air being sucked in by the motor, this is exactly what is happening with the pump. What I did to solve this issue was to remove the blue adaptor, and drill a few holes around it to let more water into the pump, I did this one hole at a time and re-attatched the hose after each one, I ended up drilling 10..... 11/64 size holes into it before the pump would stop rattling, and there is more than enough water being pulled through the skimmer hose to operate the skimmer at 100%.
I hope this helped anyone else encountering this problem