I have a 97 Grand Am with a 3.1 that keeps getting hot.Mostly when in town it gets hot.Fan comes on when needed.It is a closed system and we keep bleeding the air out through the bleeder,then add coolant when motor is cooled off.Can smell coolant but can't find a leak.No oil in coolant and no coolant in oil.Did a compression check on all cylinders and are ok. What's next?