dumb question
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Joined: Sep 2003
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From: hawaii
Car: 87 firebird
Engine: 305 tbi
Transmission: 5spd
dumb question
well i got my first car.. 87 firebird fi 305. i had some overheating issues but was solved with a gallon of coolant and a gallon of water.. it still could use some more. i ran the car today for about a minute, when i shut it off i hear a "pssss" noise. its coming from this thing. also can you tell me what the other things are?
and another question: someone said that when i put in coolant i should have the car running, otherwise i can crack the raiator when i start up the car... is that true?
thanks a lot
and another question: someone said that when i put in coolant i should have the car running, otherwise i can crack the raiator when i start up the car... is that true?
thanks a lot
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Car: yy wife, crazy.
Engine: 350, Vortecs, 650DP
Transmission: TH-350
Axle/Gears: 8.5", 3.42
The "what is this thing?" is the heater control valve. It directs hot coolant (oxymoron
) to the heater core when you slide the doohicky to hot.
The lower one is the AIR diverter.
The pump it's attached to sucks air in, then pushes it into the exhaust manifolds when the engine is cold (or in 'open loop'), then to the cat when the engine is warm (in 'closed loop').
The "PSSSSSST" is a heater hose. I'm gonna bet though that the sound you're hearing if from the AIR diverter, not the heater hose because you're not seeing coolant, are you?
) to the heater core when you slide the doohicky to hot.The lower one is the AIR diverter.
The pump it's attached to sucks air in, then pushes it into the exhaust manifolds when the engine is cold (or in 'open loop'), then to the cat when the engine is warm (in 'closed loop').
The "PSSSSSST" is a heater hose. I'm gonna bet though that the sound you're hearing if from the AIR diverter, not the heater hose because you're not seeing coolant, are you?
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From: hawaii
Car: 87 firebird
Engine: 305 tbi
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i dont see any coolant, but the thing is when i move the heater hose, the noise will go like pssSSsssSSSsss, and it really sounds like its coming from that hose clamp at the end of it
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Car: yy wife, crazy.
Engine: 350, Vortecs, 650DP
Transmission: TH-350
Axle/Gears: 8.5", 3.42
Originally posted by p0rk
also, is it possible i may be very low on coolant again, and its just pumping hot air?
also, is it possible i may be very low on coolant again, and its just pumping hot air?
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Joined: Apr 2001
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From: USA
Car: yy wife, crazy.
Engine: 350, Vortecs, 650DP
Transmission: TH-350
Axle/Gears: 8.5", 3.42

Check to make sure the sound you're hearing isn't from that small hose on top of the control valve.
That's the vacuum line that comes from inside the car. If it's leaking the heater control valve will never open.
That may explain why you hear it when you move the control vavle around.
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From: Oklahoma City, USA
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If your coolant is still low, a leaky heater hose would just blow air instead of loosing coolant. Low coolant level in your system would also be one possible cause for your heater not working (no fluid in the heater core).
Try topping off your coolant level again, and see if the problem changes. If it was just low on coolant, two things may happen: Your heater may begin to work again, and your "psssss" sound may turn into a "****" activity as the leak allows coolant to get out. That is assuming that the noise truly is coming from your heater hose. If so, you may need to tighten the clamp at the end of the hose, or replace that hose.
Try topping off your coolant level again, and see if the problem changes. If it was just low on coolant, two things may happen: Your heater may begin to work again, and your "psssss" sound may turn into a "****" activity as the leak allows coolant to get out. That is assuming that the noise truly is coming from your heater hose. If so, you may need to tighten the clamp at the end of the hose, or replace that hose.
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Car: 87 firebird
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thanks for the replies guys. why is it that you have to have the car running when you add coolant? i hear that the radiator can crack if you dont, but i dont understand why.
Originally posted by p0rk
thanks for the replies guys. why is it that you have to have the car running when you add coolant? i hear that the radiator can crack if you dont, but i dont understand why.
thanks for the replies guys. why is it that you have to have the car running when you add coolant? i hear that the radiator can crack if you dont, but i dont understand why.
Originally posted by p0rk
thanks for the replies guys. why is it that you have to have the car running when you add coolant? i hear that the radiator can crack if you dont, but i dont understand why.
thanks for the replies guys. why is it that you have to have the car running when you add coolant? i hear that the radiator can crack if you dont, but i dont understand why.
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Engine: 350, Vortecs, 650DP
Transmission: TH-350
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Originally posted by D_Amlee
If your coolant is still low, a leaky heater hose would just blow air instead of loosing coolant.
If your coolant is still low, a leaky heater hose would just blow air instead of loosing coolant.
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From: USA
Car: yy wife, crazy.
Engine: 350, Vortecs, 650DP
Transmission: TH-350
Axle/Gears: 8.5", 3.42
Originally posted by Morley
If the coolant is low and boils you get steam and hot air.
If the coolant is low and boils you get steam and hot air.
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From: Charleston, SC
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Originally posted by AJ_92RS
But there wouldn't be ANY coolant around that hose? I would think there would be.
But there wouldn't be ANY coolant around that hose? I would think there would be.
hes right..
sometimes a hole is so small that it doesnt leak, but it lets out a hiss of steam
my warped thermostat housing did that for a lil while until i got around to buying a new one... it actually steamed off the paint around it (a lil rattle can black maded it look like new)..
i thought it was weird myself... the only way i found out that it was leaking there was from the hiss when its warm and the paint starting to go away.....
p0rk:
if you think its near that hose clamp, i would just replace the hose. hose is cheap and even for a beginner its less then a half hours worth of work... under 5 mins if you know what your doing...
when you fill the car do this:
take the radiator cap off
start the car
turn the heater on.
fill up the radiator
wait until the thermostat opens... when it does, the fluid level will go down alot and you can add more fluid
once you're done, shut off the car, put the cap on tight, and fill the coolent return tank... i would fill it a lil past the hot mark...
and thats it..
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