This is a symptom of the water pump not working properly or your idle speed is set too low thus not circulating enough water.
water pump. thermostat.
Remove the Radiator and have it serviced if they are able to. If not you will need to replace it, would be a good time to replace the Radiator hose's as well. Hope This Helps.
If it's overheating, it cold be thermostat, radiator or possibly other problems. If it's not overheating it could be the coolant level sensor.
Blown head gasket?
Either the water pump impeller is loose on it's shaft, or you have a leaking head gasket.
Temp sensor not working, cooling fan not working, blown head gasket.
The most common cause of overheating is a thermostat stuck in the closed position. However, other causes are: faulty water pump, clogged radiator, clogged hose(s), coolant leak or a broken drive belt. I had a 1987 legend with around 160K that was overheating. Antifreeze would boil out of the overflow. I changed my radiator and it fixed the problem.
If your 1995 Oldsmobile Aurora keeps overheating and the issue is not the thermostat or the water pump, it could be the cooling fan. It might also be the radiator (leaking) or the hoses between the engine and radiator, or the shroud could be clogged or damaged.
more than likely you need a new radiator for it, when you install it back flush the engine.
A thermostat that is stuck in the closed position is a very common cause of overheating. A new thermostat should be installed every time the coolant is changed.
When you changed the Radiator did you flush the engine to remove the transmission fluid that the already mixed with your water in the engine block. If not that would explain the presence of the fluid in the coolant holding tank.
blowed head gasket or cracked head