I drove the old 90 coupe to work this morning and said low coolant so after adding almost a gallon I finished my morning commute and then when I left this afternoon to head to the other office it said low coolant again after adding a total of 1.5 gallons since the day before. Also it sputters a little at idle when at a light. The temperature went up to red line almost 260 and when finally parked it was bubbling in the radiator as I could hear it. The oil on the dipstick looks slightly milky and is over full. No white smoke or visible leaks tho. Is this my head gasket? Has anyone else had this problem before? Thanks in advance for any advice or help. My 1st C4 so it's a learning curve for me but I will not get rid of this car.