Coolant issue FYI

[Rick Courtright]

Hi,

We've discussed the pros and cons of green vs orange coolant here
before. Thought I'd relay something I saw on the news last night:

I don't know how widespread the problem is, but apparently it's big
enough to warrant a major SoCal TV station sending in their
"investigative team" for what that's worth (news is slow?)

Anyway, the report was on GM vehicles built since '95 or '96 using
Dex-Cool coolant developing serious cooling system problems. The
problems are rust and the coolant turning to some kind of sludge in the
system, causing expensive repairs from overheating.

GM defends the use of Dex-Cool, and claims every case they've
investigated involved allowing the coolant level to drop to the point
where the overflow tank was empty and there was air in the radiator.
Owners and radiator shops dispute this, and there is at least one class
action lawsuit in the works.

Might be something to watch for if you're running orange coolant in your
Subie!

Rick

 

[Bill Putney]

Hi,

We've discussed the pros and cons of green vs orange coolant here
before. Thought I'd relay something I saw on the news last night:

I don't know how widespread the problem is, but apparently it's big
enough to warrant a major SoCal TV station sending in their
"investigative team" for what that's worth (news is slow?)

Anyway, the report was on GM vehicles built since '95 or '96 using
Dex-Cool coolant developing serious cooling system problems. The
problems are rust and the coolant turning to some kind of sludge in the
system, causing expensive repairs from overheating.

GM defends the use of Dex-Cool, and claims every case they've
investigated involved allowing the coolant level to drop to the point
where the overflow tank was empty and there was air in the radiator.
Owners and radiator shops dispute this, and there is at least one class
action lawsuit in the works.

Might be something to watch for if you're running orange coolant in your
Subie!

Rick

Interesting post, Rick.

I know that late-model Chrysler cars are supposed to use the next
marketing breakthrough (gimmick?) - which is the GL-5 grade of coolant.
AFAIK, Zerex is the only maker of it. It is supposed to eliminate
supposed problems of DexCool/Prestone Extended Life.

I've seen some technical articles on the GL-5 posted on a Chrysler forum
- I'll track them down and post unless someone beats me to it.

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

 

[Bill Putney]

Interesting post, Rick.

I know that late-model Chrysler cars are supposed to use the next
marketing breakthrough (gimmick?) - which is the GL-5 grade of coolant.
AFAIK, Zerex is the only maker of it. It is supposed to eliminate
supposed problems of DexCool/Prestone Extended Life.

I've seen some technical articles on the GL-5 posted on a Chrysler forum
- I'll track them down and post unless someone beats me to it.

I mis-typed - it's G-05, not GL-5 (I think I must've been thinking of a
type of Subaru brake fluid or transmission grease or something).

I got my education on it from thread on a Chrysler 300M forum
(http://pub88.ezboard.com/f300menthusiastsclubfrm22.showMessageRange?topicID=6.topic&start=1&stop=20).
The definitive post said: "Bill, you are right about DexCool being an
OAT coolant. However, G-05 is an HOAT (hybrid organic additive tech)
coolant, which unlike DexCool does have silicates in it. Chrysler found
that the silicates prevent cavitation erosion of the aluminum water pump
impeller. Indeed, water pump failure was the main reason they did not go
with DexCool as an extended life coolant.

The gross difference seems to be that the G-05 has low silicates (*not*
silicate-free) - apparently it has been determiend that silicates
provide some benefit in the coolant system (water pump).

Does that mean it is the best to use in all cars? Who knows. The laws
of physics are the same everywhere, but maybe there are subtle
differences in materials or finishes. If I read the info. on the G-05
correctly, it should be "best" for all cars.

An informartive post from another Chrysler forum:
http://groups.google.com/groups?q="...e=UTF-8&[email protected]&rnum=1
Here's an article referenced in that post:
http://www.imcool.com/articles/antifreeze-coolant/G05-Glysantin.htm.

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

 

[Emad Yousuf]

yeah GL-5 is a gear oil rating.

AFAIK the sludge problem caused by Dexcool was because dealerships
were putting in stop leak pellets at time of PDI's. I suppose it had
to be a normal GM practice to put theese pellets in their rad's before
the vehicle left the dealership, but appearently since the switch to
Dexcool this practice didn't stop, until GM finally put out TSB to
dealers to stop adding pellets.

 

[Hallraker]

yeah GL-5 is a gear oil rating.

AFAIK the sludge problem caused by Dexcool was because dealerships
were putting in stop leak pellets at time of PDI's. I suppose it had
to be a normal GM practice to put theese pellets in their rad's before
the vehicle left the dealership, but appearently since the switch to
Dexcool this practice didn't stop, until GM finally put out TSB to
dealers to stop adding pellets.

I have to wonder about the use of stop-leak pellets in a brand new car
anyway. Maybe it is standard procedure with every manufacturer, but it
doesn't seem useful to put stop leak into something that's new and therefore
shouldn't be leaking.

-Matt

 

[Rick Courtright]

I have to wonder about the use of stop-leak pellets in a brand new car
anyway. Maybe it is standard procedure with every manufacturer, but it

Hi,

I don't know how many manufacturers do (did?) this, but my mid-80's
Toyota pickup came from the factory with some kind of sealer, and I
understand Ford has also used it at some time. Why? Bill probably hit it
having to do with certain manufacturing processes...

Rick