overheating/loss of coolant

ok so for starters i drive a 98 cavalier its a 2.2 and it has 300,000 km on it. this past weekend i was heading home and about 30 km out of the city the heater stopped working. so since it was -30 out i decided to turn around and go back to the city, but before i could get the chance the car rapidly started to overheat and shortly it was at 125 degrees Celsius. so i pulled over and shut the car off before i did any damage to the car. i checked to make sure i had coolant and it was pissing out of the overflow tank at that time but i could see i still had plenty. so while on the side of the road i tried to see if i could pinpoint the cause of the overheating, i turned the car on and it idled fine and the temp stayed down, the fan was running the fuses were good and i toped off the bit of coolant that i had lost. everything seemed fine so i decided to drive it back into the city. within 1km the car was above 90 C and climbing so i pulled off the road yet again and shut the car off. now i check under the hood again and there is no coolant in the overflow tank and a loud gurgle is coming from the car. i fill the coolant up again and call for a tow, by the time the tow truck got there (30 mins) all the coolant was gone yet again and no puddle under the car. i tried to move the car to better position it for the driver but the car wouldn't start and still wont start.

so if anyone knows or think they know what could be wrong please let me know. from reading posts on this forum i have heard that either it could be a thermostat, water pump, head gaskets, or plugged rad. if any of those would relate to my problem please let me know and if you have any resources on how to uninstall/install these components could you point me in their direction.

as for history of the car an older chick owned it before me and she had the thermostat changed and alternator just before i bought it. its been running fine for about 30,000 km.

i had a similar situation, my gauge went all the way up so my daughter shut it off waited restarts it and the gauge went up at first then dropped to the bottom so i figured she could drive it home right Turns out the water pump blew and then the headgasket from the overheating when the gauge was shut down. is this one of chevys better ideas having the gauge shut off?
well anyways dont be surprized if its the headgasket

ok so for starters i drive a 98 cavalier its a 2.2 and it has 300,000 km on it. this past weekend i was heading home and about 30 km out of the city the heater stopped working. so since it was -30 out i decided to turn around and go back to the city, but before i could get the chance the car rapidly started to overheat and shortly it was at 125 degrees Celsius. so i pulled over and shut the car off before i did any damage to the car. i checked to make sure i had coolant and it was pissing out of the overflow tank at that time but i could see i still had plenty. so while on the side of the road i tried to see if i could pinpoint the cause of the overheating, i turned the car on and it idled fine and the temp stayed down, the fan was running the fuses were good and i toped off the bit of coolant that i had lost. everything seemed fine so i decided to drive it back into the city. within 1km the car was above 90 C and climbing so i pulled off the road yet again and shut the car off. now i check under the hood again and there is no coolant in the overflow tank and a loud gurgle is coming from the car. i fill the coolant up again and call for a tow, by the time the tow truck got there (30 mins) all the coolant was gone yet again and no puddle under the car. i tried to move the car to better position it for the driver but the car wouldn't start and still wont start.

so if anyone knows or think they know what could be wrong please let me know. from reading posts on this forum i have heard that either it could be a thermostat, water pump, head gaskets, or plugged rad. if any of those would relate to my problem please let me know and if you have any resources on how to uninstall/install these components could you point me in their direction.

as for history of the car an older chick owned it before me and she had the thermostat changed and alternator just before i bought it. its been running fine for about 30,000 km.
i bet you have blown a head gasket since it wouldn't start now i bet you pull pluggs and there wet from antifrezze and that would cause it not to start? you probably had no compression after getting hot?