Pontiac Repair: Temperature Guage/Blower/Panel, rear cylinder head, head gasket failure

Question
I drive a 2005 Aztec, purchased in October of 2004.  This car drove fine for about the first 90,000k miles. I am now at 136,000K and it is a NIGHTMARE!!! I have had several mechanics look at it. It started with the battery constantly dying. I replaced it twice in 2009. That problem seemed to clear up then the blower motor would work on on and off. In fact it stopped working in 2009 and just decided to work two days ago???  It is still sporadic and generally stays on...high!  The temperature controls on the panel do not work (most of the time).  The radio display shows half of the display. Defrost seems to work fine. Last year the temperature gauge started going crazy.  It bounces up and down into the red zone.  One mechanic unhooked the sensor so that the fan would stay on.  Another mechanic replaced the sensor two days ago. The gauge worked fine until I got stuck in traffic today. It bounced into the red zone shortly after clearing traffic. Is the car burning up or is the gauge just off? I drive about 15 miles of highway each day to and from work.  I am afraid of running hot on the highway. Please help quickly! I am going back to a mechanic tomorrow.

Answer
Hi felicia:

get rid of this. when they have high milage they fall apart. You biggest concern here is the overheating. chance are it has either a lower inatke manifold gasket that is leaking/was leaking and then the engine ran hot enough that now it has a head gasket failure usually the rear cylinder head but if it's hot enough it will damage both.

as for the radio it's an internal fault and is not fixable it has to be sent out to an AC Delco repair facility to get fixed. does this have auto HVAC (digital) controls? if so chaces are the blower motor control module is bad. If it has manual HVAC chances are the blower resistor is bad. as for the dead battery if this has any kind of add on alarm or remote start I would start looking there first.
good luck :)