Hi Guy,

I am the Chinese in Taiwan, I just get my bird ready but not A/C(I will fit it tomorrow), I found that it is really hot inside the car even in the night, it is not overheating(show about 210 degree average), why ? is that normal? my 93 Grand Am is fine(show about 150 degree average) and always cooler inside, I don't have to turn the A/C on in the night.

Is it because the firebird is old design car?? how can I make it cooler??


Pls help,

Joe

 

I would guess your problem to be with the heater line solinoid valve (off to the pasenger side of the motor. It is vacuum controlled and shuts the flow of hot engine coolant to the heater core so the A/C will work . If that valve is always open and flowing constant hot coolant through the core, then your cockpit temps will always be hot even when the heater is not on- it basically is like having the heater on but without the blower fan running, hot air will seep through it.

 

thank you, my english is not good, would you pls tell me which part sure I fix and how I fix it. (my A/C is down now but I will ask garageman to fix it)

By the way, when I stand next my car, the hot air is keep coming out from the bottom of the car.

 

actually, I believe the these engines were designed to run that hot from the factory....


to make it run cooler you will need a lower temp thermostat, and an aftermarket chip...

 

i have an 86 2.8 and it ran really hot inside the car (i could feel heat coming off the firewall, and off the underside of the dash) untill i had the barametric pressure sensor replaced, (its under the throttlebody, and about 25 bucks)

 

thank you, I can't find the "barametric pressure sensor" in the dirctionary, maybe they too "car use only word", can you show me what it look like??

thank you

 

uhh, it looks like the sensor in the stock air can, only its under the throttle body,(ill assume you have the 2.8 like me if not, i dont know what it is, i just know that the 2.8 had this sensor, because the guy at AZ was trying to get me to replace my MAT, witch i dont really have.) youll have to flush your coolent, unless you dont mind the mess..... see if you cant take it to a parts store or a mechanic and let them tell you, it also might be called an engine temp sensor or could also be the MAT (manifold air temp)

 

Another item to check is the in-car insulation. The thick jute padding that is supposed to be under the carpets and on the interior side of the firewall.

It is possible that someone has removed it. Even if it hasn't been removed more can be added.

RBob.

 

Yeah, there's no barometric pressure sensor on an 85-89 2.8.

It's the MAT. Later model f-bodies (93-up) called it an IAT, inlet air temperature sensor. MAT name (Manifold Air Temp) came from the sensor being placed into the intake manifold, which resulted in abnormal temperature readings since the sensor got heated by the engine.

There'd be no reason to flush coolant unless you're talking about the CTS, Coolant Temperature Sensor.

Starting in 1987, GM added a "heater diverter valve". This stopped hot antifreeze from going into the heater box when the climate controls were off. 82-86 had the heater hoses going right into the heater box; there's always hot coolant, which can raise the temperature inside the car when the a/c is off but the control is on "cold".

I don't like the heater diverter valve because (A) it's very breakable and (B) it's extra junk. But, you could put one in. New, they're $20, BUT, you need the a/c controls from an 87-92 f-body. The heater diverter valve is vaccuum controlled; it takes a vacuum line in from the top. The 87-92 control head has a provision for this vacuum line.