Cooling System Pressure > 24H after last run

[JOURDAN]

Wow,

I honestly didn't think this day would come. Day 2 no pressure, I have all 11.7 quarts of coolant in my system. I added the last quart this morning and she came right to the top off the fill neck.

Originally, I could only get 2 gallons of coolant in system before FULL, this is after draining engine and cooling system entirely.

So, I can't wait to go drive this morning. I really hope she can keep rad full and transfer coolant back and forth as needed.

This is so exciting, I was very close to just pulling the heads. Air trapped in the system seems to have caused all this trouble. Who da thunk?

Just for info, I had jacked up front of car and tried every trick in the book to purge air, just would NOT come out during a heat cycles with cap off. It took over a week of driving and adding coolant.

Remember, it would not let me fill, when I did it would just puke it into the reservoir bottle overflowing it and the system would stay under pressure all the time but the cooling system would work very well. In other words, Someone not as inquisitive would not have even known they had an issue.

Update soon.

[qcman]

Geez this is kind of scary sounding. I was planning on having my coolant changed out in the Spring. Is there anything I should ask them to do when the time comes? I don't want the kind of problems you have dealt with....

[JOURDAN]

Well great news, the system is working perfectly. It purged about 1 notch on reservoir dip stick, to be expected.

I will look in am to see if it is back in radiator but I have zero doubt it wont be.

In summary, this was all caused by trapped air in the system.

[JOURDAN]

Originally Posted by qcman

Geez this is kind of scary sounding. I was planning on having my coolant changed out in the Spring. Is there anything I should ask them to do when the time comes? I don't want the kind of problems you have dealt with....

I would have zero concern. This was all caused by me not vacuum filling the cooling system.

I would just say, any shop you take it too should understand and be able to fill properly under vacuum, if they can't... run

[WoodBoss]

I have found a good way to fill the cooling system is from the radiator and then from the top return line hose. I had all sorts of issues trying different thermostats and then trying to get the air out of the system. The lower hose always seemed cool. After I filled from the top radiator hose all the air came out much easier. Vacuum filling is a good way too. These cars are not easy to get the air out due to the position of the thermostat on the motor.

[DvKillar]

Does this apply to the LFX\LLT as well?

[DonM]

Originally Posted by DvKillar

Does this apply to the LFX\LLT as well?

Since I have an LFX, I'm interested in this as well. I had one shop tell me that I'm good for another year and a performance shop told me better safe than sorry. I told both shops that the car is 5 years old with 64,700 miles.

The performance shop is more expensive, but they DID bring up vacuum filling, so guess who I'm likely going to have do it? They also suggested Amsoil, but I'm sure I can talk them into Dexcool.

[JOURDAN]

WHY did the coolant not return to radiator when cool???

Well GUESS WHAT!!
.
.
.
.
.
................>>>> There was an AIR LEAK <<<<<<<<<<<<<

to be continued

[Spurshot]

Jourdan, the hose between the radiator and the recovery tank really won't see any pressure, but I agree it should hold a little pressure (3-7 psi??) as it has to seal to siphon. The cylinder head vent sounds like it sees system pressure, so it has to seal tight (yes?).

Thanks for posting this. We should check our tank to radiator hoses for leaking/looseness.

[JOURDAN]

Originally Posted by Spurshot

The cylinder head vent sounds like it sees system pressure, so it has to seal tight (yes?).

Yes, but something seems odd about that. As loose as that hose was WITH its factory clamp, I would have thought it would have leaked.

I actually pulled the line off accidentally when the system was under pressure and sprayed coolant all over.

I tested the system recovery after hose clamping the reservoir hose and the system STILL would not return coolant to radiator.

It wasn't till I twist clamped BOTH hoses that the system transferred coolant back.


My car must have had every problem in the book, what a journey, so cool to be here now.

[JOURDAN]

Originally Posted by Spurshot

Jourdan, the hose between the radiator and the recovery tank really won't see any pressure, but I agree it should hold a little pressure (3-7 psi??) as it has to seal to siphon.

mighty-vac reservoir hose end to > radiator with system sealed and it should pull vacuum. But if it leaks at radiator nipple you cant pull any vacuum, same with vent hose.

[Spurshot]

Originally Posted by JOURDAN

mighty-vac reservoir hose end to > radiator with system sealed and it should pull vacuum. But if it leaks at radiator nipple you cant pull any vacuum, same with vent hose.

Good way to check it. So....was it leaking at the radiator nipple?

[Spurshot]

Something I had forgotten about for years.

https://www.consumeraffairs.com/news...m_dexcool.html

Dexcool problems. One of them is touted as hose problems.

On my trucks, I had always changed coolant and flushed at 50,000 miles, which was about 2 years for me. I never had any problems with hoses. My last two (GM w/Dexcool) trucks made it to about 125,000 before I replaced hoses just out of precautionary maintenance (5 years ish).

[JOURDAN]

Originally Posted by Spurshot

Good way to check it. So....was it leaking at the radiator nipple?

Yes, both hoses looked great, but leaked on vacuum at nipples.

The hose internally has degraded, I am betting the dexcool is the cause.

This morning the coolant bottle is almost empty, this is the best thing ever.

My radiator and cooling system is full, no air.