1999 pontiac montana overheating. Thermostat???

just within about the past week my van has started overheating occasionally i am thinking its the thermostat i am just wondering if anyone can help to confirm it or if its something else. sometimes it will overheat and others it wont. i have been putting coolant in it every couple of days. when it overheats i check and i can see the antifreeze rushing back to the radiator.

just within about the past week my van has started overheating occasionally i am thinking its the thermostat i am just wondering if anyone can help to confirm it or if its something else. sometimes it will overheat and others it wont. i have been putting coolant in it every couple of days. when it overheats i check and i can see the antifreeze rushing back to the radiator.


i would say probably not the thremostat,most stats when they fail
will stay in the open position.if your adding coolant i would have the system pressure tested,also checking the radiator cap.
you could look around the engine, hoses,& radiator to see if you see
any stains from antifreeze

Good luck

just within about the past week my van has started overheating occasionally i am thinking its the thermostat i am just wondering if anyone can help to confirm it or if its something else. sometimes it will overheat and others it wont. i have been putting coolant in it every couple of days. when it overheats i check and i can see the antifreeze rushing back to the radiator.
You need to make sure there is no air in the system, by bleeding it out at the upper radiator hose where it connects to the engine. Also, do your cooling fans turn on? If they do, does the air that is being blown off feel hot? You should find where the coolant is going. Did you do the Lower Intake Manifold gasket yet? How many miles does it have?

About a month and a half ago i had a little leak spring out of the top corner of the radiator so i was told i could drive around with the cap loosened so it doesnt build up too much pressure and keep squirting out so i have been driving around like that since then the overheating started like i said about a week ago. Just 2 days ago i decided to tighten the cap to see what happened and after driving for a little bit i got to where i was going and when i got out of my van i heard it hissing so i popped the hood and checked the top line to the thermostat and it was rock hard thus i believe releasing the pressure from the little crack in the radiator. Also when i purchased the van i was told the water pump and Intake manifold gasket had just been replaced recently. the van has 175,xxx miles.

About a month and a half ago i had a little leak spring out of the top corner of the radiator so i was told i could drive around with the cap loosened so it doesnt build up too much pressure and keep squirting out so i have been driving around like that since then the overheating started like i said about a week ago. Just 2 days ago i decided to tighten the cap to see what happened and after driving for a little bit i got to where i was going and when i got out of my van i heard it hissing so i popped the hood and checked the top line to the thermostat and it was rock hard thus i believe releasing the pressure from the little crack in the radiator. Also when i purchased the van i was told the water pump and Intake manifold gasket had just been replaced recently. the van has 175,xxx miles.
Well I'm confused. Is there a leak anymore, or not? If there is, that is the first thing that needs to be fixed.