2005 Aztek - Can't get the air out of the lines? Blown gasket?

[Lenco58]

I'm new to this forum and desparate for help!
Several months ago our Aztek started to peg out with the alarm going off so we took it to our mechanic who changed the thermostat and bled the cooling system.
We drove it home (less than 5 miles) and the same thing happened.
Our car has been sitting at the mechanics since October 2012 and every so often he tries something new to solve the problem.
He thinks he is not getting the air all the way out when he bleeds the lines.
Oh and I also forgot to mention that he changed to a different antifreeze.
We are really trying to keep from having to take our car to a dealer garage because it costs so much but we are almost to that point because we want to drive our car.
My husband says that when the car is running it will blow hot air then cold and it will peg out and then drop down to nothing.
We would deeply appreciate any insight anyone on here could give us.
Thank you!

 

[melsg5]

Find a new mechanic, it doesnt take a 1/2 year to figure out what is wrong with a car. You may have a leak from some source including a blown head gasket. This is the bleed procedure
Close the radiator drain cock.
If previously removed, install the engine block drain plugs.
When installing the drain plugs, use pipe sealer GM P/N 12346004.

Important: On vehicles equipped with the 3.4L engine, open the coolant air bleed valve. The coolant air bleed valve is located on the top of the thermostat bypass pipe/heater pipe assembly. Close the valve once a continuous stream of coolant is expelled from the valve.

Fill the surge tank to the base of the filler neck.
Start the engine with the pressure cap off. Run the engine until the upper radiator hose starts to get hot.
If the coolant level in the surge tank is low, add the proper mix of coolant until the level reaches the full cold line.
Important: After servicing the cooling system, and if the vehicle is equipped with an intermittent low coolant light, an occasional low coolant light may be encountered during some extreme driving maneuvers. This complaint should be eliminated by removing the surge tank cap and adding coolant to a level just at or above the full cold line when the system is cold.

Install the cap onto the tank with hand tight pressure.

 

[Lenco58]

Thank you Melsg5 for you response.
I am printing this off for my husband to read and I will let you know how it turns out.
Have a good evening!

 

[GM Customer Service]

Welcome to the forum, Lenco58. We hope you're able to get to the cause of these troubles with your Aztek. let us know if you need assistance locating a dealership in your area (we understand this isn't your preferred approach to getting this addressed - just want to help where we can!).
Sarah (Assisting Stacy), GM Customer Service

______________________________

 

[SweetAztekMa'am!]

Hey community - can someone upload a photo, video, or diagram of where to find the drain cock valve for the radiator for 2004 Aztek?? Or if Rendevous or other Pontiac vehicle is similar enough, a pic of that would suffice. This is my first time trying to drain the coolant myself and I must be blind on top of my low experience points. Alternatively, I could take photos in the daylight tomorrow and maybe someone can circle it for me!

Edit: I did some homework on YouTube and NAPA and then went to look again, and I found it! Tomorrow will finally be coolant day. I'll take a picture tomorrow in case anyone else here is as dense as I am but won't have to admit it!

 

[SweetAztekMa'am!]

2004 Aztek
Pet Cock Valve (PCV) same as radiator drain valve .
Location on vehicle.