I’m not convinced this is a head gasket problem. I have had them done once before.
During the winter I had to stop driving the car do to overheating. The gage would go up then back down to normal. When it went up I could put it in neutral and bring the RPM’s up and it would go back down. After a while that didn’t work any more so I stopped driving it.
I went out for the first time today and took it to the gas station to air in the tires and it took a long time but the gage went back up. Put it in neutral and raised the rpm’s and it went back down. It is loosing coolant but I am also getting steam from under the hood?
There is absolutely NO white smoke and NO moisture in the tail pipes. This is why I'm not convinced it is head gasket related.
Anyone know what might be causing this? Thanks

 

Make, model , year,engine, yadda yadda.

 

98 STS, Northstar

 

Is your thermostat working right?? sounds like its opening when you put it in neutral??? I had overheating problems with my old school BMW, very similiar to your issues, i ended up just pulling the thermostat all together... its a cheap part so i guess it would be worth looking at... and if im completly off sorry im just a DIY guy and just learn as i go...

 

possibly the thermostat is bad. If the head gaskets were replaced then i would assume they should have used a new thermostat. Also i would check coolant level and also check the water pump out to see if its bad. those 3 things usually are the cause. Ive experienced simmilar issues when i discovered my water pump was bad. which later i had headgaskets go out shortly after replacing the water pump.