That's the only symptom. No heat. No leaking coolant anywhere. The heater control valve was replaced two weeks ago by me and I tested it then. What could lead to me getting absolutely no heat besides a bad heater core?

 

Theres a vacuum(I think, never actually looked at it, its that or mechanical) operated door inside the car that allows air to pass from the blower through the heater core and out the vents. Maybe thats it.

 

I think you may be right! I noticed less "ressitance" when moving the slider from cold to hot, like there was a vacuum leak, but I had no idea what it was. How can I got about checking it out?

 

my son had a leak in his and we looked and looked, pulled vacumn with a hand pump and couldn't find anything. i ended up making a connection to the vacumn hose at the heater control valve and running air preasure into it, only about 5 psi, and soaping it. turned out to be the switch on the heater/ac/def panel leaking. had the same problem with my iroc so maybe that switch would be a good place to start.

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-=ICON MOTORSPORTS=-

 

If it was your heater core you would lose coolant,your engine would over heat, and yes, you would see coolant on your passenger floor board. The "door" in the heating duct is most likely the reason you are not getting heat. For some specific reason it won't open. Some say it is vacum operated, if it is mechanical then it is jsut a cable, the ball at the end may have popped off. Either way you need to track the problem behind the dash. Big pain, have fun.

 

try turning the lever all the way to hot, and run a vacume direct to the heter control valve, i think w/ vacume it routes to the core and without it bypasses the core, or vice versa. if its the door, nod a painif its the heter control valve thing, its ez

good luck
-Stell

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1988 IROC 305TPI MINT!!
Mods= Accell SuperCoil, MSD 6A, Ported Plenum, No MAF Screans , K & N, 160 Thermostat+ Temp Switch
And Always Trying To Go Faster

 

Ed,

Ah, the rotary vacuum switch! Ever taken one of those apart, cleaned it, applied new silicone grease, then reassembled? Now THAT'S a fun way to spend a Saturday afternoon.

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Later,
Vader
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"Make Me Bad"
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