No heat now that its cold outside
- Thread starter Grey_Matter
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Grey_Matter
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you'd think that, but it in fact was holding vacuum, it was holding at 22psi after it settled from 27psi.
the only think i can think of that can explain it is under vacuum it was pulling the end cap tight to hold the vacuum and as the pressure went down while putting the coolant in the end cap loosened up enough to let air in while trying to suck air out of the system, when i pressurized it to 25psi it revealed the leak in the radiator
Tree Trimmer
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or you could just fill it the old fashioned way by filling it, run it to burp out some air and fill it again.
your over thinking this to much and using to many modern things. technology is biting you in the a$$.
make sure you have coolant. fill system, drive it, top system off. no more air in said system, and the small amount that would be left is not going to be enough affect your heat. drive it again, get to operating temp grab heater hose. if it's still cold its not because you have a air pocket, you have a blockage somewhere, or another reason for lack of flow to the heater core.
pull hose off both sides of heater core with motor running. make sure you have good flow from water pump which would be volume to heater core, and good volume thru the core. then blow in the return line with your mouth and verify that you have good volume back into the block. sometimes old school just works better. messier true, but better.
if your radiator wasn't leaking coolant, then what you found when you vacuumed/pressurized it wasn't affecting you. and you only have a 16lb cap, and plastic end tanks. so you might have created your own leak trying to find a leak that likely wasn't there. till you pressurized it that far past operating pressure anyways.
anyways, carry on.
your over thinking this to much and using to many modern things. technology is biting you in the a$$.
make sure you have coolant. fill system, drive it, top system off. no more air in said system, and the small amount that would be left is not going to be enough affect your heat. drive it again, get to operating temp grab heater hose. if it's still cold its not because you have a air pocket, you have a blockage somewhere, or another reason for lack of flow to the heater core.
pull hose off both sides of heater core with motor running. make sure you have good flow from water pump which would be volume to heater core, and good volume thru the core. then blow in the return line with your mouth and verify that you have good volume back into the block. sometimes old school just works better. messier true, but better.
if your radiator wasn't leaking coolant, then what you found when you vacuumed/pressurized it wasn't affecting you. and you only have a 16lb cap, and plastic end tanks. so you might have created your own leak trying to find a leak that likely wasn't there. till you pressurized it that far past operating pressure anyways.
anyways, carry on.
Tree Trimmer
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as a side note.
don't these trucks have a contraption somewhere in the heater line to block/shut off the heater hoses when the air conditioning is on full?
i installed one in my 99, out of a 07 i think. was just a vacuum operated shut off valve. when the air was on max, the truck operated a vacuum blend door in the dash to go from fresh air to recirc, so you tap into that vacuum line and when it shut that blend door, it also shut the heater hose off.
maybe yours is stuck shut, if your truck has one.
don't these trucks have a contraption somewhere in the heater line to block/shut off the heater hoses when the air conditioning is on full?
i installed one in my 99, out of a 07 i think. was just a vacuum operated shut off valve. when the air was on max, the truck operated a vacuum blend door in the dash to go from fresh air to recirc, so you tap into that vacuum line and when it shut that blend door, it also shut the heater hose off.
maybe yours is stuck shut, if your truck has one.
webb06
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That's only on 6.0 trucks. 6.4 doesn't have the heater block off valve. I agree with these other guys. I don't see a leak causing your issue. You have something else going on.
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Grey_Matter
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tried burping it the old fashion way months ago, never worked.
after a bunch of reading on the internet i found that once you get air in the heater core you will never get it out without using the vacuum tool.
it is acting as if its an air bubble, and there is nothing to show me its not.
you'd think with all of the crap ive replaced the problem would have been fixed, but it hasnt been.
everything that has been replaced:
waterpump, thermostats, blend door actuator, upper radiator hose, both lower radiator hoses, and soon to be the radiator.
i have disconnected the heater lines and made sure the heater core was not clogged, the only thing it can be with all the parts being replaced and the heater core verified unclogged is an air bubble, with a hole in the radiator that is sucking in air there is no way to get the air out of the system under vacuum, and it will not burp. the only reason i posted on here is because everything that I have done should have given me heat.
unless of course the new waterpump is bad, but that would cause an overheat, which the truck runs at normal operating temp, which also tells me the thermostats work (even though i pulled them and tested them to verify they do in fact work)
on the bright side though i am getting really good at filling and draining the coolant
and on another note, the heat worked fine before the waterpump was changed
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Stupid question...Since it worked prior to the water pump, and hasnt since, you did get the belt on correctly, and tightened the pulley bolts right? If the pump was spinning backwards, or all the bolts fell out for the pulley and the pump is not actually spinning, you could have these issues. Also if the water pump was bad, you would not necessarily see the truck overheat if the coolant at the sensor was cold. While you are changing the radiator, i would pop the water pump outand verify everything.
Grey_Matter
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I did check to make sure the belt was on correctly, seems like it is, the pulley is there, I never thought to see if the bolts are there. I'll definitely check when I wake up.
I'm pulling the radiator after I wake up to get ready for the new one, so I think i will pull the pump
08_6.4stroker
Member
I had a similar heat issue on my truck. I would have heat for a few minutes while getting up to temp then it would go cold. I could grab the heater core lines and they weren't even warm. I changed everything you did including rad turned out to be my head gaskets were blown and it would cause an air lock not letting coolant flow to the heater core.
Grey_Matter
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i sure hope thats not the case, if it is the place that built my motor is gonna have some work to do, since the motor only has about 4000 miles since the build
nbdyspclk
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Sounds like electronic panel is done,if you cant hear flapper when you cycle settings,your dash module needs replacing
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Grey_Matter
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that was literally the first thing that was changed.
New radiator is in, just waiting for a new degas bottle, cause mine is filthy
had to replace the A/C condenser too, cause it was also leaking, noticed it when i was moving it out of the way to get the old radiator out.
Grey_Matter
New member
decided to hold off on the degas bottle, put vacuum on it, it held at 25psi, never dropped.
vacuum filled it, started the truck, let it idle for about 10 minutes and low and behold it was already blowing warm air from the heater, still need to drive it to make sure, but so far its looking like the heat problem is fixed
vacuum filled it, started the truck, let it idle for about 10 minutes and low and behold it was already blowing warm air from the heater, still need to drive it to make sure, but so far its looking like the heat problem is fixed
Grey_Matter
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Definitely not fixed, time to pull the new water pump
I have a feeling my pump p is doing this
https://youtu.be/uKWsqZx6hFU
I have a feeling my pump p is doing this
https://youtu.be/uKWsqZx6hFU
Tree Trimmer
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did you pull the heater hoses with the engine running at temp and verify volume both to the core and from?
Grey_Matter
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No, simply because the system is not building any pressure.
Grey_Matter
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Not to mention it is impossible to get to the heater hoses with the intake installed since they are under it
Grey_Matter
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I'm so over this truck and all of its problems
Since I've owned this piece of crap I have dumped almost 10k into fixing it and I haven't even put 4000 miles on it since I bought it
Since I've owned this piece of crap I have dumped almost 10k into fixing it and I haven't even put 4000 miles on it since I bought it
Grey_Matter
New member
dunno, havent had the motivation to pull everything off the front end to get to the waterpump, and i dont have a wrench large enough to remove the fan.
im literally out of money at this point.
i dont think it is, cause i dont have any coolant in my oil
