Gurgling sounds when I shut it off

Sounds like water gurgling (seems like from the overflow reservoir?) When I shut it off. Just recently started overheating. Coolant full. When I tried filling coolant from a cold start leaving the radiator cap off to let it cycle through it just raised the level to where it leaked on the ground. When it does overheat(meaning anything over the halfway mark on the dashboard gauge) the temp goes back down pretty quickly when I shut it off but will consistently get hot again after that. When it has overheated it hasn't been for a prolonged period or to the where it was maxed out on the temperature gauge. No puddles underneath nor is the oil milky. Also heater doesn't really work(blower works fine) and radiator fan doesn't kick on. Maybe worth noting water pump has been replaced within past 9 months.