No Pressure In Coolant System and Not Overheating?
- Thread starter tony1679
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Originally Posted By: tony1679
. No pressure, no flow, no leaks, no overheating. Before you respond though, read my next post.
Simple you live in the Twilight Zone...
As I've already stated with no leaks and a good cap it has to build pressure... Note if you removed cap when engine was anything but stone cold, it will be slow to build pressure... Coolant had to be circulating otherwise the engine would overheat, no doubt what you thought and what was actually happening are two different things(enter that laws of physics thing again)...
. No pressure, no flow, no leaks, no overheating. Before you respond though, read my next post.
Simple you live in the Twilight Zone...
As I've already stated with no leaks and a good cap it has to build pressure... Note if you removed cap when engine was anything but stone cold, it will be slow to build pressure... Coolant had to be circulating otherwise the engine would overheat, no doubt what you thought and what was actually happening are two different things(enter that laws of physics thing again)...
part of me thinks that t-stat may not be closing all the way, or is opening too soon:
"When I got home, I was shocked! shocked2 The upper radiator hose had pressure! So did the lower, and both of the heater core hoses. Now, let me clarify, it was not the same amount of pressure as when the pressure tester was at 16psi, but I would guess it was around 10-12."
I was once baffled by a faulty rad cap. same sort of bewilderment. when I replaced it, I then found other leaks now exposed. OP may not have other leaks, but multiple problems tend to hide each other.
Need an accurate thermometer to check engine temp. NOT the dash gauge.
"When I got home, I was shocked! shocked2 The upper radiator hose had pressure! So did the lower, and both of the heater core hoses. Now, let me clarify, it was not the same amount of pressure as when the pressure tester was at 16psi, but I would guess it was around 10-12."
I was once baffled by a faulty rad cap. same sort of bewilderment. when I replaced it, I then found other leaks now exposed. OP may not have other leaks, but multiple problems tend to hide each other.
Need an accurate thermometer to check engine temp. NOT the dash gauge.
Originally Posted By: meep
...but multiple problems tend to hide each other.
Truer words have not been spoken!
...but multiple problems tend to hide each other.
Truer words have not been spoken!
Air pockets can make it feel like it has less pressure than it does (especially if the hose being squeezed has air in it). It may have just taken a few drive cycles to get the last bits of air out.
Originally Posted By: TFB1
Simple you live in the Twilight Zone...
As I've already stated with no leaks and a good cap it has to build pressure... Note if you removed cap when engine was anything but stone cold, it will be slow to build pressure... Coolant had to be circulating otherwise the engine would overheat, no doubt what you thought and what was actually happening are two different things(enter that laws of physics thing again)...
Well, what can I say? I have to agree. It defies all logic. And maybe I was wrong about flow. But I'm telling you, if it was flowing, it was 98% less than should have been flowing. The coolant in the tank never moved. Not talking about the level, but the actual coolant was stationary. Idk. I'm not perfect, I can only tell what I saw, and maybe I was wrong.
Simple you live in the Twilight Zone...
As I've already stated with no leaks and a good cap it has to build pressure... Note if you removed cap when engine was anything but stone cold, it will be slow to build pressure... Coolant had to be circulating otherwise the engine would overheat, no doubt what you thought and what was actually happening are two different things(enter that laws of physics thing again)...
Originally Posted By: The_Eric
Do you have heat now?
Nope, it has to be the 'switch' in the dash. It's next on the to-do list.
Originally Posted By: meep
OP may not have other leaks, but multiple problems tend to hide each other... Need an accurate thermometer to check engine temp. NOT the dash gauge.
Agreed. Multiple problems did try to hide each other. And the dash gauge is pretty vague.
Originally Posted By: SHOZ
Again it is almost impossible to have trapped air in a system that has the pressurized coolant tanks. Only if the level is too low and then the tank would be empty.
Prior to touching the car at all, it was very low on coolant. Only a few teaspoons of coolant was in the tank. Then I swapped the intake, that probably compounded the situation. If the air could move, I agree it should evac itself. But if it was trapped somewhere...
Originally Posted By: Vikas
- Car is NOT overheating
- Plenty of heat in the passenger compartment
- Coolant level is not dropping
So please tell me what is the problem?
Nobody ever said I had heat in the passenger compartment. I still don't. The only mention of heat was when I was referring to the cooling system under the hood:
"So if the system holds pressure, the cap is proven to be good, the thermostat seems to be working properly, and heat (but not pressure or flow) is being distributed throughout the system, what is wrong?"
Do you have heat now?
Nope, it has to be the 'switch' in the dash. It's next on the to-do list.
Originally Posted By: meep
OP may not have other leaks, but multiple problems tend to hide each other... Need an accurate thermometer to check engine temp. NOT the dash gauge.
Agreed. Multiple problems did try to hide each other. And the dash gauge is pretty vague.
Originally Posted By: SHOZ
Again it is almost impossible to have trapped air in a system that has the pressurized coolant tanks. Only if the level is too low and then the tank would be empty.
Prior to touching the car at all, it was very low on coolant. Only a few teaspoons of coolant was in the tank. Then I swapped the intake, that probably compounded the situation. If the air could move, I agree it should evac itself. But if it was trapped somewhere...
Originally Posted By: Vikas
- Car is NOT overheating
- Plenty of heat in the passenger compartment
- Coolant level is not dropping
So please tell me what is the problem?
Nobody ever said I had heat in the passenger compartment. I still don't. The only mention of heat was when I was referring to the cooling system under the hood:
"So if the system holds pressure, the cap is proven to be good, the thermostat seems to be working properly, and heat (but not pressure or flow) is being distributed throughout the system, what is wrong?"
Originally Posted By: tony1679
Originally Posted By: TFB1
Simple you live in the Twilight Zone...
As I've already stated with no leaks and a good cap it has to build pressure... Note if you removed cap when engine was anything but stone cold, it will be slow to build pressure... Coolant had to be circulating otherwise the engine would overheat, no doubt what you thought and what was actually happening are two different things(enter that laws of physics thing again)...
Well, what can I say? I have to agree. It defies all logic. And maybe I was wrong about flow. But I'm telling you, if it was flowing, it was 98% less than should have been flowing. The coolant in the tank never moved. Not talking about the level, but the actual coolant was stationary. Idk. I'm not perfect, I can only tell what I saw, and maybe I was wrong.
You'll never see the coolant move in the tank as it's baffled... Only if level is slightly above the bottom outlet will movement maybe visible... The flow through radiator is far greater tham flow into the tank through the maybe 3/8" line feeding it, small line is mostly to allow trapped air into the tank...
Here is the diagnostics procedure for the EATC system...
https://www.youtube.com/watch?v=hAqE-oYnvlQ
The problem mentioned causing incorrect air flow(usually stays in defrost), can be repaired by replacing four small rubber O ring inside the head..
https://www.youtube.com/watch?v=5IsDs-N1mvE
Originally Posted By: TFB1
Simple you live in the Twilight Zone...
As I've already stated with no leaks and a good cap it has to build pressure... Note if you removed cap when engine was anything but stone cold, it will be slow to build pressure... Coolant had to be circulating otherwise the engine would overheat, no doubt what you thought and what was actually happening are two different things(enter that laws of physics thing again)...
You'll never see the coolant move in the tank as it's baffled... Only if level is slightly above the bottom outlet will movement maybe visible... The flow through radiator is far greater tham flow into the tank through the maybe 3/8" line feeding it, small line is mostly to allow trapped air into the tank...
Here is the diagnostics procedure for the EATC system...
https://www.youtube.com/watch?v=hAqE-oYnvlQ
The problem mentioned causing incorrect air flow(usually stays in defrost), can be repaired by replacing four small rubber O ring inside the head..
https://www.youtube.com/watch?v=5IsDs-N1mvE
That 3/8" line has constant flow whenever the thermostat is open. That tank is called a Degasser tank. It is specifically designed to easily remove the air out of the cooling system. If there was air in the system it was too low on coolant.
Update - since the car held pressure for several days, I took it to get a coolant flush. They used a flush machine and used Zerex G-05 (I made sure of this). Once I got home, I check under the hood again. Surprise! NO coolant pressure. I said to myself "let me take a wild guess...." Sure enough, the tank was only ~10-15% full. The shop corrected the problem by giving me another gallon of (non 50/50) G-05.
So my question is this: why would a cooling system build pressure with a full tank, but build no pressure at all when the level is low? Correct me if I'm wrong but you guys said heat builds pressure. The heat variable has never changed....
So my question is this: why would a cooling system build pressure with a full tank, but build no pressure at all when the level is low? Correct me if I'm wrong but you guys said heat builds pressure. The heat variable has never changed....
Does the heater blow hot air?
Originally Posted By: SHOZ
The bigger the volume of air the more it can expand and the lower the total pressure. It is not the coolant that builds pressure but the free air and when hot the dissolved air that actually builds pressure.
It's a combo of both...
If the coolant didn't expand there would be no need for the expansion tank, or for that matter have cold and hot levels on the tank... That's how earlier recovery systems worked, coolant expansion pushed the excess into a remote tank, then pulled it back into radiator as the engine cools(my '88 T-Bird & '96 F-150)... In theory the radiator was always full, and generall was... Prior to recovery tanks(My '69 Fairlane & '72 Comet) you left approx 1.5" space in top of radiator for coolant expansion, otherwise it would push coolant out the overflow onto ground the first time the engine was hot...
The bigger the volume of air the more it can expand and the lower the total pressure. It is not the coolant that builds pressure but the free air and when hot the dissolved air that actually builds pressure.
It's a combo of both...
If the coolant didn't expand there would be no need for the expansion tank, or for that matter have cold and hot levels on the tank... That's how earlier recovery systems worked, coolant expansion pushed the excess into a remote tank, then pulled it back into radiator as the engine cools(my '88 T-Bird & '96 F-150)... In theory the radiator was always full, and generall was... Prior to recovery tanks(My '69 Fairlane & '72 Comet) you left approx 1.5" space in top of radiator for coolant expansion, otherwise it would push coolant out the overflow onto ground the first time the engine was hot...
My experience with Ford's pressurized expansion tanks is if it's low then there is air in the system. If it's between cold and hot there isn't. Quite different than the regular old tanks that connected to the radiator neck.
There is something wrong with how the OP is testing or interpreting things.
There is something wrong with how the OP is testing or interpreting things.
Originally Posted By: SHOZ
My experience with Ford's pressurized expansion tanks is if it's low then there is air in the system. If it's between cold and hot there isn't. Quite different than the regular old tanks that connected to the radiator neck.
This sounds reasonable, and could very well explain what is going on. This particular tank doesn't have a 'hot' level. The cold fill 'range' is about 1". The upper part of that 1" fill range nearly touches the cap. Either way, the evidence is pretty clear, low coolant=low pressure.
Originally Posted By: SHOZ
There is something wrong with how the OP is testing or interpreting things.
I'm sorry if I'm confusing people. I am trying to word things the best I can. I am pretty knowledgeable with a car, but this one has really stumped me. Although I may not know exactly what the cause/answer is, I have at least (with all of your help) figured out what negates the effect.
My experience with Ford's pressurized expansion tanks is if it's low then there is air in the system. If it's between cold and hot there isn't. Quite different than the regular old tanks that connected to the radiator neck.
This sounds reasonable, and could very well explain what is going on. This particular tank doesn't have a 'hot' level. The cold fill 'range' is about 1". The upper part of that 1" fill range nearly touches the cap. Either way, the evidence is pretty clear, low coolant=low pressure.
Originally Posted By: SHOZ
There is something wrong with how the OP is testing or interpreting things.
I'm sorry if I'm confusing people. I am trying to word things the best I can. I am pretty knowledgeable with a car, but this one has really stumped me. Although I may not know exactly what the cause/answer is, I have at least (with all of your help) figured out what negates the effect.
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