I have a 1995 saturn.it only overheats when i drive it.it does fine when it idles.i have changed the water pump thermostat fan motor and radiator cap and flushed the whole system and it still overheats.

Of the water is boiling them it has run hot. There is no way around this fact. Get a compression test done first. This should reveal if any damage has been done. Then address the boiling off problem. This can be a air pocket in the line, incorrect anti freeze mixture, sticking thermostat, water pump, cap, etc.

Since you have done the basics, more information is needed. Under what conditions does it overheat, and how severely? Only when at idle for several minutes? Could be bad fan clutch or missing/damaged fan shroud. Severely overheats so bad you can't drive it at all? Blown head gasket? You can often diagnosis this by running with radiator cap removed and see bubbles in the radiator, or also look for water in oil, or oil in the coolant. Also, check with parts store. I think certain years of these run a reverse direction water pump, and if you get the wrong one they will overheat badly.

Check that the fan is working properly, whether it is electric or a belt driven fan. A car will overheat if the fan doesn't function as originally designed.

You've already eliminated #3 and #6, so keep checking...

Priority Action Part Type Cause
1 Inspect Radiator Cooling System Clogged.
2 Inspect Radiator Radiator Fins Obstructed.
3 Inspect Radiator Cap Worn or Damaged Radiator Cap.
4 Inspect Radiator Fan Motor Faulty Fan Motor.
5 Inspect Belt Incorrectly Routed, Adjusted (Tensioned), Missing or Worn Drive Belt(s).
6 Inspect Thermostat Faulty Thermostat.
7 Inspect Water Pump Worn, Cracked or Leaking Water Pump.
8 Inspect Radiator Fan Relay Intermittent Failure

Are the cooling fans coming on?

I guess so, or you would have said
they weren't

leave well alone it runs and doesnt overheat ,thermostats come with different temperature ranges ,82?c to 98?c average is 88?c or 92?c ,dont interfere with it leave it alone its fine

head gasket, if a crean collor is on the oil cap, lools like water pump etc are good

Check to see that the electric fan is coming on, there are two fans on this vehicle. The sender for the fan is right in front of the engine near the water housing, and is a common problem. Good Luck.

You will need to Change your Thermostat. A bad Thermostat will cause the Overheat Problem as Stated above. Also, Check you Coolant Level, and see if the Water Pump is Pumping Water through the Radiator. Please Rate my Response, I need all the Help that I can Get! Thanks!

COULD BE COOLANT SENSOR,HEAD GASKET,CHECK THE TIMING,THE PROPER MIXTURE OF COOLANT,WATER PUMP.DID YOU HAVE IT CHECKED OUT?ANY LEAKS?HEAT WORK WITH FAN?