Factory Coolant

[gonetobama13]

I heard today that the coolant that has been installed in GM cars since 1996 has a tendancy to break down and possibly dammage the radiator and other cooling system parts. Since I own three GM vehicles, is this something I need to worry about? Thanks.

 

[c4c5specialist]

I heard today that the coolant that has been installed in GM cars since 1996 has a tendancy to break down and possibly dammage the radiator and other cooling system parts. Since I own three GM vehicles, is this something I need to worry about? Thanks.

HI there,
There are so many theories on this 'Dexcool breaking down', yet there is only fact here.
First, Dexcool must be mixed correctly with regular drinking tap water, and in no more than a 60% water/40% Dexcool. 50/50 is ideal, but in the hotter states, some run 60/40 and that is ok.
There are 2 major reasons for Dexcool to break down.
First, water that it is mixed with is contaminated, creating a chemical reaction, thus breaking down the mixture.
Second, contamination from combustion gases entering the cooling system. IE/ leaking head gaskets, leaking intake gaskets, cracked cylinder heads.

As far as using distilled water, I prefer that, but it is NOT required.
I make sure I test all cars at least once a year for electrolysis and contamination. This will ensure that you do not end up with the muck and sludge buildup that so many people complain about.:W

I have so many customers with many different kinds of vehicles that have over 100k, with no problems, so I really would not worry.
Like anything else, it required periodic checking and maintenance.

Allthebest, c4c5:W

 

[motorman]

HI there,
There are so many theories on this 'Dexcool breaking down', yet there is only fact here.
First, Dexcool must be mixed correctly with regular drinking tap water, and in no more than a 60% water/40% Dexcool. 50/50 is ideal, but in the hotter states, some run 60/40 and that is ok.
There are 2 major reasons for Dexcool to break down.
First, water that it is mixed with is contaminated, creating a chemical reaction, thus breaking down the mixture.
Second, contamination from combustion gases entering the cooling system. IE/ leaking head gaskets, leaking intake gaskets, cracked cylinder heads.

As far as using distilled water, I prefer that, but it is NOT required.
I make sure I test all cars at least once a year for electrolysis and contamination. This will ensure that you do not end up with the muck and sludge buildup that so many people complain about.:W

I have so many customers with many different kinds of vehicles that have over 100k, with no problems, so I really would not worry.
Like anything else, it required periodic checking and maintenance.

Allthebest, c4c5:W

i have also heard that there was some problems with the orignal rad cap material that caused this problem,correct???

 

[c4c5specialist]

Hi there,
I have never heard of that, and there is not any documents in the GM database to confirm this.
I really do not know if this is part of the issue, but GM has documented both the concerns I have touched on above.
Allthebest, c4c5

 

[1995 RedVette]

I have a late 95 that was DexCool equiped. At 110,000 I replaced the radiator and flushed the system with no problem at all. The old rad was still clean as far as I could tell by the fluid that ran out of it and I have never noticed any sludge buildup around the rad cap or overflow tank. I bought the premix 50/50 DexCool to refill the system after the rad swap and have had no problem.

C4C5, what type of test do you preform for electrolysis....etc. I would be intrested in doing the same with my cars.

Brett

 

[c4c5specialist]

HI there,
Electrolysis is easily tested with a digital multimeter.
You simply put the black lead to the negative terminal of the battery.
The red lead you put the tip in to the coolant.
You normally want to see less than .2 volt. If you have more than that, there is a concern with electrolysis and the coolant should be changed.
Allthebest, c4c5

 

[Tuna]

All my cars use DexCool or equivalent - even my 92. Can't complain. c4c5 is telling it straight from everything I've read. I check the coolant levels routinely and have not experienced any problems.

 

[gonetobama13]

Thanks all for your responses.

John K.