There are going to be a couple things you have to check. Without hearing the sound myself, the first thing I would check is the pump. Make sure there is nothing jamming it up. Something in it, or its bearings are bad. How to check, take the belt off the bottom of the machine and spin the small pulley in the rear from underneath. You should be able to freely spin the pulley to the pump.
The tub has a brake on it, So you shouldn't be able to spin it by hand. Though possible, but VERY difficult.
Another thing that maybe going bad on the machine is the thrust bearings. This is the cam mechanism that releases the brake so the tub will spin. When they go bad it sounds like you stuck a pencil in a fan blade.
But it sounds like from the way you describe it the motor is shutting off and has to cool down before it will start. I would check the pump.
I hope this helps you out. If you have anymore questions please feel free to ask. You can still ask me questions about your machine after you press the accept button.
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