I was driving my 99 Alero and it started to overheat quickly like went from normal temp to red line in about 90 seconds. I shut the heat off and it dropped back down. Then the coolant light went on. I stopped the car in a safe spot (a few miles after overhear issue) and let it idle for a few minutes then shut it off. Let it cool down for a bit checked coolant it was very low so I filled it to fill line. Coolant light stayed on but temp is running okay (goes up to 50% and stays there)
I know little about cars and need help to see what it might be or if I can fix it myself or need to get it to a mechanic. Ex-bf recently put in new thermometer but I don't know if it was done correctly. Then starter went out mechanic fixed that and mentioned something about the coolant and bleeding something? Help please!