Possible overheating, 2004 pontiac montana

Are the cooling fans working ? What are you going by to say it's overheating ? Temp .gauge . hear coolant surging in the engine , Did you replace the radiator cap. Have had a lot of customers come in saying the vehicle is overheating , it wasn't ! just bad temp gauge .

you have a GM common problem and that is a bad intake manifold gasket. GM change the gaskets to plastic and they crank and leak causing over heating. here is a picture of one i took from a 2005 pon. bonneville with 74,000 miles on it

With the car running because it reduces the back pressure have someone that knows how to do it remove the cap from the radiator and see if the radiator is full, not the bottle but the radiator itself. If the antifreeze is not moving from the bottle to the radiator it will overheat. Not having heat unless you rev the engine makes me think the radiator is either not circulating the water or it is low.

Cooling problems can be hard to pin down.

Do you know if your electric engine fan comes on? If not they should, if you had the radiator fixed how was it done, new, rebuilt, or some fix a leak in a can? Driving an over heating car will ruin it, while the car is off and has sat long enough for the engine to cool, remove the radiator cap and check the fluid, do you have enough?

If the radiator was removed and replaced something may have worked it's way loose as in a wiring harness that runs the fans, most fans have a plastic safety pin of sorts that keep the fan harness from unplugging.

Another problem may be your water pump, since it's taken a month for you to notice any problem with the car I would not think it needs to be bled. Tho it might need to be.

Take the car to your local garage and have them look at it, if you dont do anything your cars engine can become damaged.

I do hope this helps!

What are you going by to say it's overheating , temp gauge ? Have you test to see what the actual temp. is > Hook - up a scan tool ,what's the PCM - engine computer seeing for engine temp. ? 223 degress the PCM should turn on the cooling fan . You could buy a Non-Contact Infrared Thermometer With Laser Targeting at harbor freight ! Radiator very hot ????? What is the right temp .
Non Contact Infrared Thermometer With Laser Targeting

Could be a bad temp gauge . Is the coolant surging inside the cooling system ? Does it have a radiator cap ? Have you replaced it ?

your thermostat is not opening there for not allowing hot coolant to exchange into the radiator. replace thermostat.also causing you to overheat

Probably coolant temp light. When vehicle has cooled overnight, check the coolant level in the radiator. Very difficult to open radiator cap on this vehicle, because engine brace is in they way. You don't want to keep driving with this light on on, could do damage to engine.

your thermostat probably stuck closed.when you cooled it down,it opened again.change the thermostat.

Yes that is cool if it's correct. 195 F is approx.as low as you should have. I'd change it. Be sure to run with cap off, and heater on (not defrost) while refilling system. Wait for rad fan to come on 2 or 3 times before you put cap back on, then add coolant to return bottle as needed. Make sure rad fan only comes on when up to normal running temperature. If it runs all the time, it may be causing low coolant temperature too.

sounds like you could have faulty gauges to meby check them out.... and yes its posible that its pluged