Overheating and no error codes

If the tank did not drop then check the tanks cap, it may not be venting properly, however you may also have a air locked cooling system or a radiator that has a very restricted coolant flow, I have also seen the water pump blades corrode so bad that they won't circulate coolant. When was the thermostat last changed? The cooling fans will also run if there is a problem with the engine management system even if the check engine light is not on. Do not overheat these engines cause they will blow a head gasket even if just slightly overheated.

Do a compression test , It's a 25 year old car and it's probably not the first time it has over heated , Don't drop a bunch of money into it .

If the plastic coolant recovery tank is not pressurized you need to remove the radiator cap with the engine cold. Fill the radiator to the very top. Put the radiator cap back on and top off the recovery tank. If the tank was empty, just refilling it will do nothing. The coolant will just sit there. When you fill up the radiator with the engine cold and you start the engine, the coolant will expand and force the air out of the hose that connects the recovery tank to the radiator. Then after you shut off the engine and it cools down the coolant will contract and pull coolant from the recovery tank back into the radiator. Hope that helps! Jim