coolant elbows

[JGBuick]

2-EHA is in a lot of dexcools
a lot of coolants

Thats stuff that contributed to failed intake gaskets many years ago because coolant got behind the gaskets and destroyed the plastic carriers
The compound breaks down silicone
Silicone is highly migratory, and ANY silicone in the combustion chamber can quickly foul O2 sensors


Silicone isnt bad but its not necessary. Its potential to be pressurized into places easily over time or broke down (into things floating in your cooling system) is what the concern is


use coolant, its plenty slippery and does work and is meant to be there.

Good points. And this is also why I don't use DexCool anymore.

 

[2000ltd]

Good points. And this is also why I don't use DexCool anymore.

I thought they reformulated the dexcool?

 

[BuickGirlFromMars]

I thought they reformulated the dexcool?

the problem of the intake gaskets wasnt the fault of dexcool, it was gm for having poor maching tolerances and using an incompatible plastic carrier material for holding the sealing portions of gaskets

Any coolant that passes the seals , or gets behind the cavity of another things seal, would eat the plastic carrier, then the gaskets would fail because no longer supported properly.

THe issue of dex reformulation is separate and occured about 2003-04 ish and had to do with encouraging microbial growth and melting rubber hoses on some model lines (possibly supplier or hose quality at play too)

 

[BuickGirlFromMars]

Good question. ?? Do you have access to any records? There's also other gaskets that "could" have been used that were "upgraded" to include better materials. These were supposedly meant to deal with the DexCool issues. If your lower gaskets were repaired/replaced, then I'd venture to say they used a better gasket. I'm not 100% sure on if you can see any of the gasket protruding..??

Here's a thread from when I did mine awhile ago - Upper intake is leaking on 2002 Buick lesabre

You still have the plastic elbows?? Well... it's just a matter of time. You can watch them or replace them. But sooner or later....

Will the new DexCool 'eat" the current gaskets on your car? Don't know. Some say it's all about "Air in the system" and the condition of the system. Some say it's never been an issue.

Soooo.... lot's of conjecture and guessing here. The main thing is to be aware of the potential problems. Do a search on this site and you'll find lots and lots of posts.

the plastic carrier of the lower intake gasket should be able to be seen if you look closely near elbow , the updated gaskets used metal carriers

 

[BuickGirlFromMars]

I have the Carfax which showed an intake gasket and manifold repair in 2002 so I'm hoping it was the limit gasket and a revised intake manifold. My system came with dexcool in it at 87k and that's the reason I'm keeping it since it's had it for over 25 years so why change it. I'll just keep it fresh with a drain and fill every year.

neither the gasket or manifold in 2002 were properly fixed yet, but keeping good coolant and not currently having issues is the best course

 

[2000ltd]

the problem of the intake gaskets wasnt the fault of dexcool, it was gm for having poor maching tolerances and using an incompatible plastic carrier material for holding the sealing portions of gaskets

Any coolant that passes the seals , or gets behind the cavity of another things seal, would eat the plastic carrier, then the gaskets would fail because no longer supported properly.

THe issue of dex reformulation is separate and occured about 2003-04 ish and had to do with encouraging microbial growth and melting rubber hoses on some model lines (possibly supplier or hose quality at play too)

I'm switching to g-05

 

[JGBuick]

the problem of the intake gaskets wasnt the fault of dexcool, it was gm for having poor maching tolerances and using an incompatible plastic carrier material for holding the sealing portions of gaskets

Any coolant that passes the seals , or gets behind the cavity of another things seal, would eat the plastic carrier, then the gaskets would fail because no longer supported properly.

THe issue of dex reformulation is separate and occured about 2003-04 ish and had to do with encouraging microbial growth and melting rubber hoses on some model lines (possibly supplier or hose quality at play too)

I've read differently and from what I've learned is that there is a chemical (2EHA) in DexCool that is a plasticizer (spelling?) Which means it's going to interact with certain plastics/gasket materials. So, I've avoided any coolant with this formulation and also changed-out my gaskets & intake for metal units.

 

[2000ltd]

I've read differently and from what I've learned is that there is a chemical (2EHA) in DexCool that is a plasticizer (spelling?) Which means it's going to interact with certain plastics/gasket materials. So, I've avoided any coolant with this formulation and also changed-out my gaskets & intake for metal units.

I still have the plastic lim gaskets so I'm changing the dexcool this weekend. Do you think G-05 is ok to use for coolant?

 

[JGBuick]

I still have the plastic lim gaskets so I'm changing the dexcool this weekend. Do you think G-05 is ok to use for coolant?

Yes, AFAIK, G-05 does not contain 2EHA and would be a good coolant to use. I've used it in my Miata for years. It should be fine in your Buick

 

[BuickGirlFromMars]

I've read differently and from what I've learned is that there is a chemical (2EHA) in DexCool that is a plasticizer (spelling?) Which means it's going to interact with certain plastics/gasket materials. So, I've avoided any coolant with this formulation and also changed-out my gaskets & intake for metal units.

yes

thats what I said, i just added how the failure occured. Dexcool has always been compatible with the gaskets themselves the actual sealing o ring/elastomer bits

The part it has not been compatible with is the stuff around/behind , because that material was not expected to be in contact with coolant and it wasnt adequately looked into (in case)either

The actual machining tolerances GM uses on their cast iron parts and aluminum parts play a part because the gaskets theoretically would need very little "carrier" if we had spread out clamp loads and PERFECT flat and no casting/pourous places and the gaskets were installed right.

But cast iron gets porous , and im sure the tolerances accepted by GM for engine components is concerningly high because of the amount of "passed QC" parts would have defects down the line from dexcool slipping past and eating the plastics
These carriers create a plane for these seals and holds them in place while they do their job. to have the plastic fail, it would cause blow outs and then cars in shops for new gaskets (like what happened , with teh same type of defect parts that failed already with the same components that had coolant slipping past lol

 

[2000ltd]

yes

thats what I said, i just added how the failure occured. Dexcool has always been compatible with the gaskets themselves the actual sealing o ring/elastomer bits

The part it has not been compatible with is the stuff around/behind , because that material was not expected to be in contact with coolant and it wasnt adequately looked into (in case)either

The actual machining tolerances GM uses on their cast iron parts and aluminum parts play a part because the gaskets theoretically would need very little "carrier" if we had spread out clamp loads and PERFECT flat and no casting/pourous places and the gaskets were installed right.

But cast iron gets porous , and im sure the tolerances accepted by GM for engine components is concerningly high because of the amount of "passed QC" parts would have defects down the line from dexcool slipping past and eating the plastics
These carriers create a plane for these seals and holds them in place while they do their job. to have the plastic fail, it would cause blow outs and then cars in shops for new gaskets (like what happened , with teh same type of defect parts that failed already with the same components that had coolant slipping past lol

Will they fail then no matter what coolant is used? I just decided to flush my new dexcool because of this risk, I have the plastic lim gaskets still, and don't want to change them but don't want them to fail because of coolant degradation.