VW Coolant

[gatesj at mailblocks.com (John Gates)]

The novel:

That's a real good question... I did read a lot about different 
coolants and one thing that pops into mind is that the silicates are 
bad because they can be slightly abrasive to water pump bearings and 
after a while they precipitate out and make a gummy mess if you don't 
keep it changed, but the upside is not only are they a good corrosion 
inhibitor, but they will actually patch erosion damage on water pump 
impellers that comes from cavitation.  G-12 has nothing similar in it 
to "patch".  I also understand that how traditional coolants inhibit 
corrosion is that they deposit a very thin layer of their inhibitors, 
whether they are phospates, silicates, borates, or a combination of 
these, on all surfaces inside the cooling system.  This insulates the 
parts from any corrosive elements.  G-12 or other OAT coolants do not 
do this, they are formulated to make the solution not corrosive for a 
longer period of time.

I have had, especially on my VR6, blue crusties at the end of hoses 
where they clamp onto fittings, well in advance of hose failure.  The 
first time I didn't recognize what was happening, I just thought I 
wasn't getting a good seal, and then the hose finally burst at a ring 
of weakened material just ahead of the fitting barb.  What was 
happening was that the inside of the hose at this "ring" had finally 
given way and the coolant was getting into that middle layer with the 
fabric and migrating up to the end of the hose through there.  I never 
really lost an appreciable amount of coolant while this was going on 
though.

I wonder if the blue stuff is better at "repairing" or plugging tiny 
leaks like this because of the silicates, and just masking a problem 
that is already there, while the G12 is not?  I know I saw tiny pitting 
on my cylinder head inlets on my Scirocco where the o-ring goes.

I personally think that the G-12 was VW's attempt at trying to shield 
themselves from customers who don't maintain their cars during the 
warranty period.  I bought my VR6 new, didn't change the blue stuff 
until about 3 years, when it had JUST started turning greenish yellow.  
3 years was well within my 10 year/100,000 mile powertrain warranty, 
and if I had let it go, I might have had headgasket leakage from 
pitting that they might have had to fix.  I have since changed coolant 
at least every 2 years and have not had headgasket problems or any 
other unusual cooling system problems, corrosion or deposit buildups in 
8 years and 150,000 miles.  The inside of my cooling system is as clean 
as can be and my water pump lasted until about 135,000 miles, quite 
high for a VR6.  The blue stuff is great if it's maintained properly.  
I did not have my Scirocco for the first 10 years of its life and it 
came to me with nasty old green stuff so I cannot say if it would have 
been in better shape with blue that was changed often.

This is one of the places I remember reading a bit about the chemistry 
in layman's terms that I could understand:  
http://www.imcool.com/articles/antifreeze-coolant/

John Gates
--
'85 Scirocco
'97 Jetta GLX

-----Original Message-----
From: David Utley <fahrvegnugen@cox.net>
To: John Gates <gatesj@mailblocks.com>; tyrone27@gmail.com
Cc: scirocco-l@scirocco.org; glxtasy@hotmail.com
Sent: Wed, 15 Jun 2005 17:02:39 -0400
Subject: Re: Re: VW Coolant

No please, nitpick away...  :-)

So, on the reddy-pink G12, why do you think this stuff oozes out of the
connections at the head or at the T-stat?  This is what I have seen on 
the A1s,
which is why I will not recommend the G12 now as an upgrade...

I am interested in your take, it sounds like you have a bit more 
schooling/hands
on on this...

David
>
> From: John Gates <gatesj@mailblocks.com>
> Date: 2005/06/15 Wed PM 01:23:38 EDT
> To: fahrvegnugen@cox.net,  tyrone27@gmail.com
> CC: scirocco-l@scirocco.org,  glxtasy@hotmail.com
> Subject: Re: Re: VW Coolant
>
> The red G-12 is silicate free, but the G-11 aka G-48 most definitely
> has silicates, it is one of the most abundant corrosion inhibitors in
> that preparation.  The silicate is what precipitates out in the G-11
> after a while, leaving the gooey mess at some of the connections, and
> this is one of the reasons why they went to G-12.
>
> There is nothing wrong even with phosphates if you don't use hard
> water, hard water makes phosphates precipitate out and cause all sorts
> of problems.
>
> Note that the G-12 bottle says "phosphate and silicate free" since 
it's
> a true OAT technology coolant (unlike Dex-Cool which is a hybrid OAT),
> and the G-48 says only "phosphate free".
>
> Just nitpicking here.
>
> John Gates
> --
> '85 Scirocco
> '97 Jetta GLX
>
> -----Original Message-----
> From: David Utley <fahrvegnugen@cox.net>
> To: John Gates <gatesj@mailblocks.com>; tyrone27@gmail.com
> Cc: scirocco-l@scirocco.org; glxtasy@hotmail.com
> Sent: Wed, 15 Jun 2005 12:20:21 -0400
> Subject: Re: Re: VW Coolant
>
>
> >
> > From: John Gates <gatesj@mailblocks.com>
> > Date: 2005/06/15 Wed AM 11:38:45 EDT
> > To: tyrone27@gmail.com
> > CC: scirocco-l@scirocco.org,  glxtasy@hotmail.com
> > Subject: Re: VW Coolant
>
> > Sounds like another opiton.  I think that like VW blue, Toyota red 
is
> > not that much different from green except it has high borates and 
low
> > silicates or something.
>
>
> I am told that VWs need coolant that is phosphate and silicate free...
>
> David
>
> '83 GTI, Daily Driver...
> '87 16V, parts car
> '82 pickup, 2.0 16V, collecting dust...
>

'83 GTI, Daily Driver...
'87 16V, parts car
'82 pickup, 2.0 16V, collecting dust...