No Heat

[dhd669]

hello fellow GA lovers lol, I could use a little help here I have a 94 GA SE 3.1 v6 last week it started having some problems with the cabin not getting heat. Here is what i have done to try to fix it so far.
I started with trying to give the cooling system a burping , didn't get any air and fluid level is fine. oil isn't milky nor is the coolant oily and there is no performance issues that would be related to a blown head gasket. so i flushed the system out and still no heat. Today i have tore down the inside of the car to check the heater core. Found no leaks and it has been replaced with new style core. So with everything tore down still, I run the car the core gets hot and with everything not bolted back up i have heat, but i do feel alot of cold air blowing at the firewall i figure that it is normal due to the blower has to get air from the outside bla.. bla.. bla... i could be wrong. i checked the air doors they seen to be working fine, ie: the close all the way and open fine as i can tell. so i button everything back up and again no heat. so anyone got a clue to help me out thanks

[tenspeed]

i checked the air doors they seen to be working fine, ie: they close all the way and open fine as i can tell.

If your core is hot enough, it has to be the doors. You might have a vacuum leak or some interference.

[dhd669]

i checked the doors and even took off the crowl and still no damn heat why would i get great heat with all the plastics off and then put them on no heat. how would i Begin checking for a vacuum leak. I'm stumped and I'm ready to run it into a wall and collect the insurance

[rixGAphx]

but i do feel alot of cold air blowing at the firewall i figure that it is normal due to the blower has to get air from the outside bla.. bla.. bla... i could be wrong. Yeah, I think you're wrong on this.

True, the blower DOES 'hafta get air from somewhere', but the 'where' is the entire issue.
If you want 'cold', as selected by the dash knob, then the fan sucks nearly 100% outside cold air thru the cowl vent, because the blend door/damper is open.
If you want 'hottest possible' as selected by the knob, then the vac controls should close that blend door; the 'where' becomes 'recirculation of warm cabin air, drawn from above passenger's tootsies.'

i checked the air doors they seen to be working fine, ie: the close all the way and open fine as i can tell.You can't see or touch the blend door very easily, it's deep inside the ductwork.

Check your underhood vacuum, from the nipple at the passenger-rear of the intake manifold to the vac reservoir (under the battery) to the HVAC control panel.
IIRC, the Cruise Control on your '94 is vac-operated, so make sure there isn't a leak, there, also. A faulty pre-'96 CC at the same time as HVAC problems indicates a vac source problem.

Try re-cycling/re-booting the knob, from full-cold to full-heat, but ONLY when the engine is 'on' so that it's drawing vacuum.
Highest vac is achieved by driving fast (20 mph?) in FIRST GEAR, about 4500 rpm, then taking your foot off the gas to close the throttle plate.
That'll suck the snot out of an elephant's trunk, and *may* cause an otherwise-balky damper to finally actuate.

Or the damper vac motor could have a damaged internal diaphragm, or the control rod from the vac motor o the damper could be disconnected, or the tube from the HVAC knob to the vac motor could be disconnected/leaking.

Hope this helps,
-Rick

[rixGAphx]

how would i Begin checking for a vacuum leak.Your 14-year old rubber connections and nylon tubing can easily be cracked, kinked, etc.
1. Visual check.
Especially, in the area where somebody might have worked recently, like installing a stereo underdash.
2. Run the engine at idle, and spray 'Winter Starting Fluid' (or carb cleaner) at every vac-looking hose and connection. At a leak, the stuff gets drawn-in and raises the idle speed.
Don't try this inside the cabin, due to explosion hazard in case of spark.

I'm ready to run it into a wall and collect the insuranceThis is always an option with GA's older than about 5 years.

:eek:

[dhd669]

I'm going to try these suggestions right now ill check back in about an hour thanks

[dhd669]

well i tryed the first geart thing but with one problem there is no 1st gear only 2nd and it is computer contrloed so after a certan rpm computer automaticly shifts geat no matter what gear you have it in.
cruse dont work so cant really check that then again it might not work cuz of vac problem.
now im goin to AZ for some startung fluid be back to let you know

[dhd669]

Well heat now works (for now) thanks for the help !! 195,657 miles and still going, just keep it alive and looking good