New Intex Pool Pump - Noisy - not pumping

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?

I don't think thats normal behavior for any kind of pump, although I have heard that those new Intex pumps that come with the pools are very under powered. Have you checked to be sure there is nothing blocking the pump or its screens and that all the air has been bled out first? I think they have an air release somewhere. Air in there will cause it to overheat and then it can burn out. Sounds like that may be whats happening. Also, does that pool have a valve at the return or inlet to the pump that may be blocked or shut? You may want to check all of these items.

The inlets are both open and I didn't see anything blocking the pump on initial inspection. I'm just puzzled as my older pump never acted or sounded like this.

I'm in the process of drying the old one out. Next time I'm at the house, I'll hook it up and pray it works.

As for the new one, it's out of warranty even though it's never been used. If it burns up, I'll just throw it away.

Sounds like there is air in the line. Did you prime your system?

Yes I primed the system and yes it does still sound like it has air in it, which is weird.

Took the hoses back off it and found there's a small mesh screen inside the inlet. I took that part of the pump apart and cleaned it out. Got the pump back up and running and it did the same thing within the hour. Checked the screen again and it had more stuff stuck to it, but not as bad as before. This is what's getting past my skimmer and should be getting caught in the filter, but it's not getting that far. Needless to say, I put the pump back into the shed and am now using my old one again now that it has dried out.

In the 3 years I've owned my older pump I never had this problem. It's just the newer one that's giving me trouble. I'm guessing it's a design flaw, but who knows. In any case, it's not worth the aggravation.

It sounds to me that your new pump is moving more fluid than your old one.
I'm no expert on pool pumps, but I've worked on industrial pumps for 25 years. When a pump sounds like it's got gravel in it, it is starving for fluid. It's not air in the line. Air doesn't make any noise by itself. If the suction line is not flowing enough water to the pump, then the pump gets loud and sounds like it's got gravel in it. The term is cavitation. It means that the intake line is partially blocked or too small for the pump.