Cooling System Pressure > 24H after last run

[JOURDAN]

I am really hoping the community can help me do a few experiments.

I had been fighting coolant leaks and engine not holding pressure, air in system.

After correcting all leaks and bleeding the system holds pressure very well now.

However here is the problem, Like the title says... 24 hours later she is still under pressure.

The cooling system WILL NOT pull coolant BACK INTO reservoir because ZERO Vacuum every happens.

The cooling system will purge out about 1" of coolant and then NO MORE coolant will be transferred to reservoir. The coolant stays even with top of coolant fins inside.

So... in some way the system is stable, but under pressure and not functioning correctly.

No other symptoms exist with exception I still smell a tiny tiny bit of coolant after working her.

My first thought is I have a BAD HEAD or GASKET and combustion gasses are getting INTO my cooling system.

I'm puzzled... Need help ....so I don't take this thing apart for nothing.

Would anyone who can see if their Camaro 6.2 is still under pressure after cold 24 hours or even less, just all the way cold again??

If you listen to your reservoir bottle when releasing radiator cap you would hear it blowing bubbles in your bottle.

Thanks in advance!!

[JOURDAN]

I just preformed a bottle test, put the reservoir tube into a bottle of water and with engine up to temperature I observed zero air bubbles in bottle, even revving engine.

If it were combustion gases I would think bubble would appear as the cap let off pressure

[christianchevell]

With the age of your Camaro now you should have changed out all the antifreeze with a flush to avoid acidity which it builds over time that can pit badly aluminum and the radiator cap which does weaken. And no there is no pressure after a while it dissipates....I would suggest changing out the radiator cap. The system should put out when hot under pressure if the level is high enough a small amount into the puke tank, then yes when cold suck some back in...if you have not installed say a thermostat upside down ...and yours may yes be due to be changed now with the cars age...springs...the cap and thermostat age....good luck....

http://www.carparts.com/classroom/coolingsystem.htm

[Spurshot]

Sounds like maybe the radiator cap is a problem.

[JOURDAN]

Flushed three times, new therm, new cap, new heater core, new hoses.

Oil heater delete, block pluged, pressure tested.

Leak down > Excellent, compression > Excellent

Cooling system acts perfect - zero observed problems - except always pressure in system

------------------

The only thing I did not do is vacuum fill the cooling system, I have ordered the proper equipment, and may try that next.

I was starting to wonder if trapped air could somehow gas off and create residual pressure after cooling cycle.

[JOURDAN]

Well.... after fighting this pressure for over a week, this morning the system had zero pressure.

The coolant bottle is one notch from FULL and the radiator is about 2 quarts low.

So.... I have added 1 quart, its about 1" from fill neck now - NOT FULL.

My guess is it will purge that quart into my reservoir bottle once hot.

Anyway what great news, something odd is going on but I do not think its catastrophic, something simple at this point, hoping.

Update soon

[JOURDAN]

So I ask.

What is the coolant level in YOUR 6.2 Camaro radiator WHEN ICE COLD?

Could someone please look in theirs and see if the coolant is at top or low near fins.

Thanks

[JOURDAN]

Update:

it did not purge the 1 quart of coolant yet, brought it up to 210 degrees at idle for about 20 minutes.

Upper rad hose is HOT

Lower rad hose COLD

??

[DonM]

[JOURDAN]

Well... as it turns out the temp sensor is in the head and there is a huge discrepancy between its reading and the actual temp at the thermostat.

So it can read 210 and not have popped a 190 thermostat yet.

So after driving for a few miles the thermostat opened and the system did not purge the quart I added this morning.

I am becoming very hopeful this is just a matter of air trapped in system manifesting in odd ways.

I now believe if you don't vacuum fill this particular cooling system, your screwed tell it sorts its self out. fingers crossed.

tomorrow morning hopefully I don't have pressure and I can attempt to add the last quart of coolant without it puking it out.

BUT, that would still beg the question... WHY doesn't pull its own coolant from the reservoir... oh well.

[Olddudesrule]

Just got back from a drive, or I would check right now. After it cools completely, I will check the radiator level. I've topped off at the overflow, but actually have never cracked open the radiator. If the system is full, the pull as it cools should be minimal from the overflow to the radiator, and vice versa, the push into the overflow from the radiator should be less than a pint or two I would imagine....

[Spurshot]

Originally Posted by JOURDAN

I am really hoping the community can help me do a few experiments.

I had been fighting coolant leaks and engine not holding pressure, air in system.

After correcting all leaks and bleeding the system holds pressure very well now.

However here is the problem, Like the title says... 24 hours later she is still under pressure.

The cooling system WILL NOT pull coolant BACK INTO reservoir because ZERO Vacuum every happens.

The cooling system will purge out about 1" of coolant and then NO MORE coolant will be transferred to reservoir. The coolant stays even with top of coolant fins inside.

So... in some way the system is stable, but under pressure and not functioning correctly.

No other symptoms exist with exception I still smell a tiny tiny bit of coolant after working her.

My first thought is I have a BAD HEAD or GASKET and combustion gasses are getting INTO my cooling system.

I'm puzzled... Need help ....so I don't take this thing apart for nothing.

Would anyone who can see if their Camaro 6.2 is still under pressure after cold 24 hours or even less, just all the way cold again??

If you listen to your reservoir bottle when releasing radiator cap you would hear it blowing bubbles in your bottle.

Thanks in advance!!

I think your problem is the system is not properly filled. A coolant recovery system should have a full radiator. Right to the tippy top and then some.
https://www.howacarworks.com/cooling...cooling-system

[DonM]

Originally Posted by Spurshot

I think your problem is the system is not properly filled. A coolant recovery system should have a full radiator. Right to the tippy top and then some.
https://www.howacarworks.com/cooling...cooling-system

With my recent questioning of my temp sensor reading 220* in stop & go traffic (once), I did check my fluid level in the radiator. While the recovery tank read on the low end of the stick when hot, the radiator itself was filled to the brim when cold ... maybe I need to recheck the overflow when cold and add a bit there.

Edited to add: When I get my flush done, should I make sure they refill the system using a vacuum machine and not just a "drain, flush & fill?"

[JOURDAN]

Originally Posted by DonM

Edited to add: When I get my flush done, should I make sure they refill the system using a vacuum machine and not just a "drain, flush & fill?"

That's the ways its looking, I think futile any other way unless you torture yourself for weeks trying figure out whats happening ...lol