Nissan Repair: sentra cooling, nissan sentra, backflushing

Question
here's my question... 93 nissan sentra 1.6 liter, there is rust all in the cooling system, I have flushed the whole system, but there is still rust. and sludge, is this a radiator problem or something else?

Answer
Paul,

If the coolant went bad and sludged up the system you might be looking at a new radiator if you cannot get the crud and sludge out to your satisfaction.  I would look at getting the radiator replaced if it were me.  Be gentle on backflushing as it can blow the heater core.  So, flush it a couple of times more before you take the plunge for a new radiator.