i have replaced my thermostat, tried to bead all the air from the bleeder plug. and it is still overheating. has the rear ac and heat.
still gets overheats with the guts of the tstat removed.(old)

i know it is not a blazer. but it is my moms, and i am stumped

 

Have you checked the water pump to make sure it's moving water? Sometimes the water pumps fail and that can cause overheating. Have you checked the heater core for blockages? Have you flushed out the cooling system? Have you verified that the fan is working properly? Is the radiator blocked? Since you've already done the easy things you need to look at the overall cooling system and test every part of it.

 

Yes,Toby hit all the obvious,which is what you should be looking for. My daughter has one of these(though I've never seen it except in pix) and there is a forum for these units as well! I'm sure its a simple solve issue!

 

04 Durango.... 4.7 engine? You're screwed. Those things are junk. There are SO many things that go wrong with that engine... actually all the .7's are the same way. I've seen them bend rods from being hot. Is the crankcase overfilled? They are bad to blow headgaskets as well. I'd get someone to pressure test it, I bet you either have a bad gasket or a cracked head.