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Durdeydolla 01-26-2013 05:01 AM

Cabin heat help...
Hello, I have a 84 olds with a 1996 lt1 & 700r, the first 9-8ss lol, but my problem is no high heat in vents. Floor vents is luke warm but dash vents or ice cold. Fixed blend door, change thermos to 180, right mix of coolant, new heater core, im thinking my vacuum hoses behind dash or off. The ones that go to seperate blends doors then back behind conttoller. As any one know how to configure that hose wheel on controller

timothale 01-26-2013 07:12 AM

Air lock ?
Do you have air in the heater core. some heater cores are higher than the engine. and need to be bled . If so loosen the upper heater hose, slide it back aways , Drill a 1/8 in hole slide the hose back in position snug the clamp. start the engine, warm it up then loosen the clamp and slide the hose to uncover the bleed hole and let any air out , then reposition the hose and tighten the clamp.

Durdeydolla 01-26-2013 07:41 AM

I didnt think of that but wouldnt the bleeder on thermostat housing fix that??

timothale 01-26-2013 07:59 AM

air trapped
If the core is higher air can be trapped, not get pumped out. , In the factory they use a suction system. it collapses the radiators hoses sucking out the air then they pump in the coolant.

Durdeydolla 02-14-2013 09:17 PM

Bleeded system and attached loose vacuum hose, fixed vent flow but still not blowing hot air. If temp guage goes to 185 then its luke warm at stand still but if I drice it gets cold again. Checked my mix its 50/50, new thermostat and heater core, idk its driving me crazy cuz its so simple but I cant put my finger on it

S10 Racer 02-14-2013 11:15 PM


Originally Posted by Durdeydolla (Post 1646590)
Bleeded system and attached loose vacuum hose, fixed vent flow but still not blowing hot air. If temp guage goes to 185 then its luke warm at stand still but if I drice it gets cold again. Checked my mix its 50/50, new thermostat and heater core, idk its driving me crazy cuz its so simple but I cant put my finger on it

Could be a bad thermostat even if it's new. Could also be a water pump issue or heater core. I would disconnect the heater hoses and force water through one of them with a garden hose and see how it flows. This will also help flush it out a bit but more importantly it will give you an idea how well water is moving through it. You also need to check how well the water pump is working. After you get the heater hoses hooked back up, back the radiator cap off to the first stage where it's loose but won't come off. This will not allow the system to build any pressure. Start the car and let it come up to operating temp and slowly remove the radiator cap and look inside. If the coolant is not moving, you have a problem with the water pump or possibly the radiator itself is plugged up. The coolant should be circulating anytime the motor is running and the thermostat is open.

Durdeydolla 02-15-2013 06:05 AM

Yes, I have circulation in cooling system. Both hoses to heater core or hot. During bleeding coolant did shoot out in a nice stream. So pressure is not an issue. Its an lt1 motor, could reverse cooling be a factor?? And im thinkin it could be main blend door?

ssimpala 02-15-2013 07:15 AM

That's a common problem with the LT1. I have three of them that I've hotrodded and run a 160 thermostat in and have no heat...I live in Texas and only drive them to shows, dragstrip etc, so no big deal. There is a good discussion and some "fixs" on the Impala forum Hope this helps, Bill.

TMF Lindbeck 02-15-2013 09:11 PM

Is there a vaccum operated shut off valve that blocks hot water from circulating in to the heater core when the heat is turned off? Some cars have them some don't. If you do it would be on the firewall and could be broken or disconnected causing low flow and in turn making your heater core useless.

FmrStrtracer 02-16-2013 10:26 AM

Where are you picking up your inlet coolant from? If youre drawing you water from the top of the motor, youre getting the coolest water/coolant. Find where the coolant leaves the block and goes to the radiator and try to tap your heater there.

Try a 210* thermostat to see if your heat increases.

Id buy a Factory Chassis Service manual(not haynes/chiltons) for your car, usually not to expensive online. It will describe the vacuum routing and door operation of your heating system, plus everyother component of your car.

Durdeydolla 02-27-2013 05:21 AM

Bleeded system and now it seems worse. (Front end jacked higher when bleed) I have mitchel on demand, hayne and chilton books. Im trying not to rebuild the system again for something that might be a 20 min fix im overlooking. New water pump, new t-STAT, new heater core, radiator just about a year old with no leaks, 50/50 mix im running, and I have 2 options on t-stats from autozone 160 and 180, im running 180. If it sits while running its warm at best but if Im driving then its cold. Double fans set to come on at 210. And my radiator is capless, everything is added in resivour tank. Levels or capped off

gearheadslife 02-27-2013 05:40 AM

does this olds(guess'n cutlass) have a/c..
recheck that all the doors in the heaterbox are working..
I don't remember a shut off valve for the heatercore(like posted above) on g body's
it may bypass the heatercore when on vent and a/c that door might be stuck on vent, blocking all heat..
start car and get warm.. then touch upper and lower hear hoses, both warm...??
remember lt1 is reverse cooled.. do you have the heatercore lines reversed?? the water try'n to pump uphill through the core could stall the flow...

Durdeydolla 02-27-2013 10:01 AM

I was wondering about my heater hoses routing, I have the left side heater core hose on the bottom inlet on water pump. And the right side hose on heater core going to top inlet on water pump, wasnt to sure if heater core sides matter, it runs A1. Just no heat. And its a b-body, and yes my resovoir tank is placed higher then engine with a t-fitting going into heater core hose left side (passenger side) to bottom of water pump

Durdeydolla 02-27-2013 10:26 AM

pics of my lt1 set up
3 Attachment(s)
Heatercore hoses placement, not to sure if they on the right side

boothboy 02-27-2013 10:42 AM

Let me ask a question. Lets not consider temp right now. As you go through all the different modes on your selector switch with the blower turned to high, does the air come out of the appropriate vent with full air force?

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