If the Chevy Celebrity radiator is smaller that the Saturn radiator it might well overheat from not enough cooling capacity.
If the Chevy Celebrity radiator is the same size or larger than the Saturn radiator I would think it would not over heat.
Possibilities: Cooling fan not working. Low on coolant. Clogged radiator, radiator hose or block.
The petcock on a 1989 Chevy Celebrity is at the bottom of the radiator on the drivers side.
The petcock is at the bottom of the radiator on the drivers side of the car.
Bad radiator, gaskets, water pump, thermostat
The drain is near the bottom of the radiator on the drivers side of the car.
The drain cock is on the driver's side of the radiator at the bottom of the end pan.
Check coolant level Cooling fan working? Dirt or clogged radiator? Defective radiator cap?
The thermostat on a 1989 Chevy Celebrity is located under the water outlet fitting. Follow the upper radiator hose, it will end at the water outlet.
The starter is on the bottom of the block on the side nearest the radiator.
The coolant fan relay on a 1988 Chevy Celebrity with 2.8L V6 is on the radiator support bracket behind the right hand headlights.
In order of probablility: low coolant level, faulty thermostat, plugged radiator, damaged water pump, collapsing radiator hose.
I believe it's on the radiator tank near the fill cap.