on the pump note, those pumps have a bad pump failure rate, would just buy a better one, also how old is that one, some I hear run for a couple years, some a couple weeks, and if it was a loud grinding noise the motor is locked, no chance of repair unless you drop a new motor in it. On the how long can you run your system, depends on the system, usually it'll tell you I ain't running no more if it hits the thermal shut down point, you may get some extra time if you underclock and volt it.