Over heating

Try bleeding air from system like this remove cap from overflow tank fill with antifreeze to full mark leave cap off and start vehicle and let idle you will notice level in tank start to rise this is normal once thermostat starts to open level in tank will drop add more antifreeze to full mark then put cap back on.

After you have tried bleeding the air from the system and it still overheats, I would determine if your cooling fan(S) is working. After that, about the only other things to check would be blockages or a bad temp sensor.

I replaced all those on 2005 Aztek plus the thermostat and still had to rebuild the head. Found a Mexican to do job for $900 and no overheating in a year since. Not once. 100 000 miles when head replaced. I got Pep Boys to do a $49 diagnosis with chemicals and they confirmed head gases in coolant. Course they wanted 2500 for the job. turned out to be the head was warped and not the gasket. Remachined it and away we go. Does use fair amount of oil but runs like the honey it was before. These Azteks are kind of like Toyotas, at least for me. Run long and well. When you do fix it, parts are not cheap and labor is not either. My other Aztek, a 2001, has 275,000 miles.