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Dex-cool yes-or-no?

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Old Aug 1, 2007 | 12:16 PM
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Default Dex-cool yes-or-no?

Having hearing all the bad press recently about Dex-cool antifreeze what is your general concensus on the stuff? My recently 2000 SSEI has this stuff in the motor currently with no issues ( knock on wood). My inquiry was after checking my fluid levels and notices what a slimey mess this stuff looks like. Is this correct? I have read about numerous bloggers flushing their systems and going green. What do you think?
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Old Aug 1, 2007 | 12:21 PM
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My truck had a nasty coating of the stuff on the inside of the radiator, had it flushed out immediately and replaced with...more dexcool.

The LeSabre on the other hand, runs nothing other than the Prestone Dex-Compatible coolant. I wouldn't have it any other way.

If you have the inclination, I'd replace it with the orange Prestone Dex-Cool or the green "Mixes with anything" Prestone coolant. If you don't, just be sure you drain and flush the system regularly. Which you should do with any coolant...
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Old Aug 1, 2007 | 01:06 PM
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Agreed...the suggestions here are to flush and head with either
Prestone long life
Green
Mix with any.
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Old Aug 1, 2007 | 02:16 PM
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GM'* Dexcool has anti-rust inhibitors that are also known to degrade nylon and silicone.

Source:
http://www.imcool.com/articles/antif...l2007Part3.php

Here are the other parts of the long article:
http://www.imcool.com/articles/antif...l2007Part1.php
http://www.imcool.com/articles/antif...l2007Part2.php

Oddly enough, we have a 97 Cadillac that had Dex from the factory, and we had no problems with it.
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Old Aug 1, 2007 | 04:35 PM
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Originally Posted by willwren
The thread is directly about DEX.

Here'* a set of L36 LIM gaskets at about 30-35k miles. Please note that the DEX was probably already acidic when these were installed:










Now for the explanation:

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Old Aug 2, 2007 | 01:27 AM
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This is a question that I've been wondering myself for a while.

My mechanic brother says to get the Deathcool out of there asap.

But GM keeps putting it in there, so it can't be that bad... can it?

And so I'm torn.

But am I reading the above correct, if I understand that the Prestone Long Life has the long-life benefits of Dexcool without eating Nylon and Silicone? If so, I may be sold...

And the real question for the Bills (boost and wren): So Dexcool is bad. What do YOU run?
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Old Aug 2, 2007 | 07:06 AM
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The other Bill having a 93 and 95 was blessed with Greenness from the factory.

My car was given Dex and I swapped it out to Prestone long life after having the car about 5 months when i changed the lower intake gaskets (with plastic as the aluminum ones were not yet out).

The other Bill and I haven't been 100% in agreement about Dex lately. I found it odd that GM changed the 3800 gaskets for the Dex years to a different material (aluminum frame). They didn't change the coolant, which we know sludges..and becomes acidic.

However ... when I pulled my lower intake again with Prestone LL after about a year or so..the gaskets were collapsing in on themselves.... that we always blame the Dex for doing. My question at that point was..is this an interior gasket for the application which led to GM changing the gasket to aluminum frame. If Dex wasn't present and the gaskets still collapsed in.. hmmmmmmm

I still use the Prestone LL, haven't seen any sludging from it and so far it'* working well. Although I seem to be changing it more than once a year with various mods or projects.
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Old Aug 6, 2007 | 11:34 AM
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We do alot of lower intake gaskets on the 3400 and 3100'*. We don't do many manifolds for the 3800'*, though they are not uncommon too arounds here.

Mostly its the cheap plastic gaskets and the cheap plastic componements that degrade and break down, not the dexcool. I find dexcool isn't a problem as long as the system is maintained and there are no air pockets in the cooling system. We use Zerex 50/50 dexcool complatible coolant. It mixes with dexcool well, and causes very few problems for us.

GM has been comming out with revised intake gaskets as well as other aftermarket companies. The new gaskets are a better design, (steel) and should last the life of the motor. Its a shame really, GM has some really nice motors and cars out there that get plagued by this problem, and its no wonder GM is struggling lately.
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Old Aug 6, 2007 | 05:27 PM
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Originally Posted by BillBoost37
However ... when I pulled my lower intake again with Prestone LL after about a year or so..the gaskets were collapsing in on themselves.... that we always blame the Dex for doing. My question at that point was..is this an interior gasket for the application which led to GM changing the gasket to aluminum frame. If Dex wasn't present and the gaskets still collapsed in.. hmmmmmmm
Thats very interesting and may explain why gasket problems are not as prevalent on the Northstar engines which run Dex.
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Old Aug 6, 2007 | 07:18 PM
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Indeed, as Northstar owners do not complain about DexCool in their aluminum engines. Whenever this question is posed at my Aurora site, swapping DexCool for green is not suggested.
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