what do I do to cause it to stay at a normal temp ?
on 1994 Chevrolet Camaro

My car has been overheating and as soon as it hits 240 to 260, it cools down. I have put antifreeze/ coolant in it. but it gets hot and then cools down.

Asked by for the 1994 Chevrolet Camaro
Start by replacing the thermostat.