My old 56633 2500 gallon Intex pump, that I had for my old ring style pool, just died so I went ahead and hooked up the one that came with 4' x 18' metal frame pool I bought last summer. The new pump is a 1500 gallon pump, and this is the first time it's been out of the box. It's noisy (sounds rattly), barely moves water and seems to stop all together (though still running) after about 20 minutes. When I look in the pool, the return is not returning anything - or at least I can't see or feel any movement.

Is this normal behavior for these pumps?