This might be a silly question but I am doing it for the first time and don't know much about cars so i need some advise please. My coolant light comes on when i start the car. After driving it for 5 minutes it goes off. I am thinking to add some coolant. I know the plastic coolant holder on the driver side under the hood. I will add to that. Do i also have to open the radiator cap on the passenger side and add there as well. My car is 1998 Grand Prix GTP.
Thanks