New antifreeze types and properties
Bob Bartch (bbartch@jps.net)
Sun, 22 Aug 1999 08:54:19 -0700

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Everything you want to know.... from www.motor.com and motor
magazine........

Keeping It Cool
by Paul Weissler

August 1999. Coolant incompatibility and the usual
assortment of great service tips highlight the coverage from
this year's NARSA convention.

The coolant inside each of the reservoirs-from a Toyota, a
'98 Dodge Intrepid and a VW Passat-looks about the same
color. It's red...well, maybe pink...or is it orange? Yup, must
be that new orange OAT (organic acid technology) coolant,
with the special inhibitor package that provides a promise of
longer coolant life.

In reality, only one of the three is a "pure" OAT antifreeze-in
the VW. And as such, Volkswagen carries no replacement
recommendation. Then again, VW never has had a
replacement interval, even with its conventional coolants,
something no one at VW has ever explained to our
satisfaction. The antifreeze in the Dodge Intrepid may be
orange and contain some OAT, but it's really what we call a
"hybrid," and it may be going away after a brief trial. The
Toyota? It uses a traditional Japanese coolant-a
high-phosphate, nonsilicate formulation.

If you want to take this whole thing a step further, look at a
Dodge truck. You'll see green coolant in its reservoir. Looks
about the same color as the green stuff in a Mazda, but the
coolant in each is totally different. Well, at least all coolants
are compatible. Or are they? As we're finding out, there's a
fair amount of incompatibility among coolants, both with the
new extended-life antifreezes and when mixing the new OAT
coolants with what we now call "conventional" formulas.

Questions & Answers

The National Automotive Radiator Service Association
(NARSA) has been wrestling with this issue, trying to sort out
the confusion and see where the real-world problems exist. It
has been getting coolants analyzed and talking to scientists
and chemists, plus engineers at the vehicle manufacturers.

NARSA admits that it doesn't have all the answers, but it may
be able to help you avoid the major pitfalls. Here are NARSA
answers to some frequently asked questions. First, though, a
few caveats: Many changes are occurring in coolant
chemistry, and NARSA believes Daimler/Chrysler U.S. will
be going to a new coolant formulation very shortly. Ford,
meanwhile, has said it's considering a hybrid for its U.S.
cars, but for the present is continuing with conventional
American coolant.

Those caveats aside, here's a service-oriented summary of
what you need to know to help minimize the chances of doing
something wrong with your customers' cooling systems.

First of all, forget coolant color; it's just a dye and means
nothing. GM and Texaco, which codeveloped the Dex-Cool
brand of OAT antifreeze for late-model GM vehicles, picked
orange to distinguish this type of antifreeze from conventional
American coolant, which is green or gold. Volkswagen, which
also uses an OAT formulation as mentioned earlier, has a
similar dye that most of us think is pink. Toyota's traditional
red dye is a totally different product. Although the orange
coolant in Chrysler L/H models contains OAT, it's a custom
hybrid, with Chrysler specifically forbidding the use of
Dex-Cool in these cars. It would have been better if Chrysler
had used some other dye color.

What kinds of coolants are out there? Aside from the limited
sale of propylene glycol to environmentalists, it's ethylene
glycol... about 93% ethylene glycol, that is, plus water and
specific rust and corrosion inhibitors. Here's a rundown:

Conventional American coolant (green or gold) contains
silicates (a long-used aluminum corrosion inhibitor) and other
inhibitors. Silicates work quickly to protect aluminum, but also
are depleted relatively quickly in service. They're also
somewhat abrasive (being based on silicon-sand), so they've
been implicated in water pump seal wear. Advocates say
tests show silicates last longer than was commonly believed.
And with the latest seal materials, they actually do a better
job of protecting the water pump, because they both resist
cavitation erosion-corrosion and "repair" any that occurs.

OAT coolant (orange or pink) contains no silicates and no
phosphates. It's a blend of two or more organic acids, a
specific class of inhibitors with slow-acting, long-life
properties. Texaco's Havoline Dex-Cool (also sold under the
Goodwrench label by GM) was the first example. Prestone
and Peak also have introduced OAT coolants that are
chemically compatible with Dex-Cool.

Conventional Japanese coolant (green or red) contains no
silicates, but has a heavy dose of phosphates and other
inhibitors, including a modest amount of one or two organic
acids.

Conventional European coolant (blue or yellow) contains a
low dose of silicates and no phosphates, but does include
other inhibitors, including one organic acid.

Hybrid European coolant (blue or green) is similar to
conventional European, but with a much greater dose of
organic acids. It's a balanced formula designed to have the
silicates provide the primary protection for the aluminum,
then allow the organic acids to provide long-term protection.

Hybrid American coolant (green or orange) contains a
moderate dose of silicates, plus a blend of organic acids.

So with all these coolants around, who uses what?

GM cars and light trucks built since the 1996 model
year use Dex-Cool OAT. VW/Audis since 1998 use an
OAT, but it's a different formula. The '99 Mercury
Cougar uses an OAT-type coolant that's reportedly
similar to Dex-Cool.

Except for the '99 Cougar, Ford U.S. vehicles use
conventional American antifreeze. And except for the
hybrid coolant in '98-on L/H cars (Intrepid, Concorde,
300M), so do Daimler/Chrysler U.S. vehicles.

Mercedes uses a conventional European antifreeze
that has been upgraded, and may outlast the
conventional stuff.

GM Opel products sold here (namely the Cadillac
Catera) use Dex-Cool.

Volvos and BMWs use a hybrid European.

Japanese cars use a conventional Japanese coolant.

Korean cars use either a conventional Japanese or
conventional European antifreeze. (It depends on who
did the in-depth engineering for the Korean company.)

Medium-duty and heavy-duty diesel vehicles should use
specific formulas, with additives that meet
recommended practices of the American Trucking
Association's Maintenance Council. Some OEMs use
specific OAT formulations. Cummins, on the other
hand, forbids pure OATs, and recommends a specific
silicate-containing hybrid with heavy-duty additives as
part of a "lifetime" fill maintenance program.

Some problems exist when you mix OAT coolants with the
conventional stuff, or when you do an OAT retrofit. Much
evidence points to the fact that if you mix conventional
American antifreeze (silicated) with an OAT type in a system
with virgin aluminum (that's not protected by either type),
severe corrosion will result. The producers of OAT coolants
approve their use in any system, provided it's been
thoroughly flushed out first.

NARSA's position is more conservative (factoring in the
issues raised by the vehicle makers), and is based on the
assumption that all you can obtain for service is conventional
American green/gold or an American orange OAT. NARSA
still recommends conventional American green/gold
antifreeze. Specifically, NARSA recommends the following:

Use Dex-Cool or an aftermarket OAT only in GM cars
that were factory-filled with Dex-Cool. Although you can
top up with any of the three OATs available, the best
practice is to flush out the system first, to remove at
least 90% of the old coolant.

Do not use an OAT antifreeze in any Ford product
aside from the '99 Cougar. It may attack certain gasket
materials (particularly in Ford modular V8s). It also can
be responsible for water pump cavitation
erosion-corrosion, reports Ford.

Do not use an OAT coolant in any Chrysler product.
OAT has been shown to increase damage from water
pump cavitation erosion-corrosion, particularly in some
truck V8s. If you can't get the specific Chrysler orange
hybrid, flush out the system and install a conventional
American antifreeze.

In European cars equipped with a hybrid or
conventional European antifreeze, use a conventional
American silicated antifreeze.

In Japanese cars equipped with silicate-free coolant,
rely on this bit of history: These coolants never were
sold in any quantity in the U.S. Japanese cars seem to
survive nicely on conventional American products, so
the safe approach is to stick with them. Both Japanese
silicate-free and conventional American coolants
contain phosphates, so they share that key inhibitor.

On heavy-duty vehicles, stick with the OE
recommendations.

For temporary use, as in a roadside emergency,
mixing different coolants is better than using just plain
water. But the system should be flushed out and refilled
with the correct coolant as soon as possible.

What if a customer insists on a retrofit to get long coolant
life? Widely reported tests by Valvoline-Zerex and Prestone
indicate that cooling system protection with conventional
American silicated antifreeze can last for 5 years/100,000
miles if the system has been maintained well from the start.
That means being continuously topped up and the antifreeze
concentration maintained at 50% to 60%. That same
treatment, by the way, is needed to enable an OAT antifreeze
to safely go 150,000 miles in the five-year period. In any
case, the quality of the water, which is half the fill, may be as
big an issue as concentration.

There are reports that NARSA is pushing distilled water.
Who wants to bother with that, you ask? The answer: If you're
in an area where the water is very hard and the shop doesn't
have a water softener, why not? A gallon of distilled water is
cheap insurance. How important is coolant concentration to
system longevity? When the specified 50/50 mix gets too
low-maybe 20% antifreeze-that's an area where any
antifreeze (silicated or OAT) can face a problem. Other
radiator and heater corrosion problems occur when a poor
job is done on removing old coolant, which may be so bad
that a fresh fill of either type also turns bad very quickly. This
problem has surfaced on systems using conventional
American silicated antifreeze.

Some problems have been reported with systems using
Dex-Cool. Although aluminum is considered the most
sensitive material for coolant performance, GM also has
been dealing with cast-iron rusting problems on Chevy/GMC
S-10s with the 4.3-liter V6. The problem, first reported by
NARSA member shops, seems to be in still another but
related category-low coolant level. No one is sure why the
4.3-liter V6 is so sensitive to a low coolant level, but it's
causing rusty sludge buildup in the radiator and heater. GM
will release a choice of flushing procedures shortly. You can
top this one up, but make darn sure it's with a 50/50 mix.

There are some special precautions to take when performing
mechanical repairs on a vehicle's cooling system. The first,
obviously, is to never mix coolants. Another is that if the
system contains an OAT and the customer wants to maintain
the long-term service interval, stick with an aluminum
radiator. Remember, OAT coolants contain a copper-brass
corrosion inhibitor but may not protect adequately against
lead solder, particularly high-lead solder. That concern
originally was recognized by GM, which prohibited retrofitting
its Dex-Cool OAT to older models with copper-brass
radiators. Now, GM's tech service people say they can't
approve any retrofit of Dex-Cool into any system that was
factory-filled with a conventional American silicated
antifreeze.

What replacement intervals you follow depends on which type
of coolant is used and the type of service the vehicle will see.
With conventional American green/gold, if the system is kept
full with a 50% to 60% mixture of a quality coolant, a
replacement interval of 2 years/30,000 miles is incredibly
conservative. Chrysler and Ford long have approved about 3
years/50,000 miles, and there's evidence that even these
intervals are conservative for a well-maintained system. If the
mix is diluted further, all bets are off.

With a quality OAT coolant, if the system is kept full with a
50% to 60% mixture, the 5-year/150,000-mile interval is fine.
If the coolant is diluted, corrosion problems could crop up.

The real world says that medium/ heavy-duty diesels don't get
a coolant change, that the factory fill is run until it's time for an
engine overhaul. Both Cummins with its hybrid coolant and
Texaco with its heavy-duty OAT have supplementary additive
packages to extend the life of the factory fill. Cummins
recommends installing an additive package (or a new
coolant filter, which also contains the additives, depending on
application) at 150,000-mile intervals (about once a year).
Texaco recommends using its additive package at
300,000-mile intervals (about every two years).

Cavitation Problems

As coolant flows through the water pump, it may boil at the
inlet. As it flows to the pressure side of the pump, the bubbles
collapse with explosive force. This is called cavitation, and
the mini-explosions of the bubbles can pockmark the pump
chamber and impeller, knocking off the protective layer of
corrosion inhibitor (erosion) and exposing the metal surfaces
to corrosion. Because silicates act faster than OAT
inhibitors, they recoat the exposed surfaces, for a so-called
fast repair. In addition, there are claims that OAT coolants
are more prone to cavitation than conventional coolants. GM
designed its cooling systems to minimize pump cavitation,
prior to the change-over to the Dex-Cool OAT.

Lesson 1:
A man is getting into the shower just as his wife is
finishing up her shower,when the doorbell rings The wife quickly wraps herself in a towel and runs downstairs. When she opens the door, there stands Bob the next-door neighbor. Before she says a word, Bob says, "I'll give you $800 to drop that towel. "After thinking for a moment, the woman drops her towel and stands naked in front of Bob. After a few seconds, Bob hands her $800 and leaves. The woman wraps back up in the towel and goes back upstairs. When she gets to the bathroom, her husband asks, "Who was that?" "It was Bob the next door neighbor," she replies.

"Great!" the husband says, "did he say anything about the $800 he owes me?"

Moral of the story: If you share critical information pertaining to credit and risk with your shareholders in time, you may be in a position to prevent avoidable exposure.


( Lessons 2-5 behind cut )

No matter where you get gas at, You will be getting deoderants (additives) in your gas. It is a legal standard, so you will always have some anyways. It helps to always fill up at the same place, preferably with a lot of business. I always go to Chevron to fill up. I added Techron when I was getting 20 miles to the gallon, and now I get about 30-40. If you fill up at cheap ghetto stations, there is a good chance you will get water in your gas, because they cheat the standards. I did a lot of reading on the internet on the best gas to use. chevron, exxon, i think shell were good

Anyway, I'm working at a US Postal Processing & Distribution Center in SLC
training their electronic technicians. It just so happens that one of the
technicians previously worked (for 16 years) for a petroleum pipeline
company that runs from San Bernadino to Las Vegas. His (former) company
didn't own the product, they were just paid to pump the fuel from CA to NV.
The main control center is in CA and there are multiple pump stations and
valves along the length of the 200-mile pipeline.

He said they actually have 2 parallel pipelines, a 14" and an 8", that run
along the right-of-way of the Union Pacific railroad (UP is actually a 51%
owner of the pipeline). I asked him if they pump 89 octane one day and 94
octane the next, and he replied that they pump multiple grades in one day in
the SAME pipeline.

As an example, he said they'll start by pumping thousands of barrels of 87
octane into the pipeline, then immediately follow that with thousands of
barrels of 91 octane, and then follow that with thousands of barrels of 94
octane. As long as the pressure in the pipeline remains constant (controlled
by the pumps and valves) the 3 fuels will move along as "columns" or
"slugs".

There will be some mixing of the fuel grades at their "boundaries" due to
the turbulence created by the pumping stations and the bends and turns in
the pipeline. This "boundary layer" fuel is called "trans-mix" for fuel that
is MIXed during TRANSmission.

At the Las Vegas end the first few thousand barrels are pumped into the 87
octane tank. As the boundary layer approaches, the fuel is periodically
sampled and tested. The transmix is then pumped into a separate tank. In
this example, the 87 is diluted with some 91 - good for the 87. The 91 is
diluted with 87 and 94 - kind of a draw. The 94 is diluted with 91 - oops.

The goal is to minimize the amount of transmix, but even so he said that the
fuel companies actually buy back the transmix and RE-refine it, whatever
that means. Hey, good for the pipeline company, they get paid to transport
it, paid to "mix" it, and paid again for the transmix.

I asked him if they ever do a "column" of gasoline followed by a "column" of
diesel and he said they don't do that because the resulting transmix is
useless. He said their 14" main is used for grades of gasoline and the 8"
main is used for diesel, commercial jet fuel (Jet-A), and military jet fuel
(JP-8). McCarran AFB is right there in Las Vegas.

I asked about the "old days" when we were able to buy leaded and unleaded
fuels and he confirmed that those fuels would share the same pipeline. I
asked about the leaded fuels leaving a coating on the inside of the pipeline
and he also confirmed this. Oh well, can't prove that it was responsible for
damaging any cat conv back in the 80s.

Sorry for the long post, just relaying some pertinent info.