Over heating problem

Have you checked your oil? Does it look like a milkshake? Also how old is your radiator cap? Might want to do an exhaust gas test on the coolant. If exhaust gas is found in coolant then blown head gasket.

Head Gasket problems are definitely a known issue with this vehicle and motor.

idk your mileage, but my Montana required new head gaskets at 80K, now at 170K having heating/overheating issues. had thermostat replaced, heater core flushed, and am not told heating assembly is cracked (?) I could smell antifreeze thru the cold air coming out the vents befor taking it in. I just read on a different site, Edmund.com, that there is an aftermarket auxillary coolant that often gets overlooked. This make and model seems to have a lot of heating/cooling problems. Any comments would be helpful

Ive had my van over heat went to betten chevy and it was intake gasket the radiator was going low then after that my overflow went way up

My van starts to over heat but the is goes to Normale after like a min changed thermostat so I have now ckue

My radiator is overheating but I have heat coming out of it .i let the water out of it and put more water in and it still are overheating. What could be the problem?

I would say try checking your oil. If your oil level is oddly way over the level of how to have or if it is the color of chocolate milk, it's possible you might have a head gasket issue. Vehicles with the 3.4L V6 engine are known for having head gasket and overheating problems

Have a 1999 Pontiac Montana are there 3 thermostats this time I bought GM thermostat went through 5 water pumps replace Reservoir in thermostat sensor whole top end engine rebuild no antifreeze in oil and is not burning antifreeze through the exhaust.

so is having a head gasket bad and fixable