My son has a 95 Bonneville SE with the 3800 engine with 85K miles on it. Actually had been running real well until last week. He went to a concert and it took about 20 minutes to get out of there and the car overheated.

The car has overheated twice more since then requiring more coolant. He knows nothing about cars and I have not been around when it happens. Any suggestions to what to look for would be greatly appreciated?

Pressure test the cooling system to see if there are any leaks. Next verify that the fans are coming on.

When the car warms up, do you see the T-stat opening on the temp gauge (temperature rises, then drops and then slowly rises and holds at 200F)? If not, the T-Stat needs to be replaced.

After refilling the radiator it became apparent the problem was the water pump.