ok, so in the past 3 to 5 days my coolant light keeps coming on. I fill the coolant and get any air out of the coolant system, i think ( by letting it run and over flow?). But after a day or two the light comes back on. the car run on different then it always did ( not that good). can someone help me with this.

do a coolant pressure test and look for leaks.

thats what i was going to. i just wanted to know you anyone had an clow about it