97 Lumina coolant not circulating

Problem first started with no heat and temp gadge was going up and down and when it finally stayed at normal I would get heat. I notice it was low a bit on coolant so I added some.

After a while the overflow coolant tank light lite up and when i stopped it came off and coolant level in the tank was ok.

Now the coolant started to all go back into the overflow tank and temp started rising to go into red and I stopped and let it cooled down a bit and loosen the rad cap and coolant sucked back into the rad and was ok to drive 20km home.

Now only thing it does when it runs idle after a while I get only cold air and coolant goes into overflow and no coolant will flow from the 2 screws to bleed the air out but when I first start it there is coolant comming out of them.

Now wandering if it's the water pump or something else that can be the problem

Tks in advance for any input

Welcome to AF. Most likely a stuck thermostat or it is air bound. Possible water pump but highly unlikely.

After this, have you refilled the system and were you able to bleed out the air? Does the system still accumulate air and eventually give the same symptoms (push coolant into over flow, no heat, temp gauge spikes...)?

Could be a leak that only happens under pressure causing the problem. Had that on one of my '91s, stumped me for a bit. (turned out to be radiator drain plug on mine).