Pontiac G6 Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
12 Posts
Discussion Starter #1
Hey guys,

I just bought a brand new G6 GT Coupe and thought I would start this thread regarding the notorious GM coolant "DEX-COOL". Dex-Cool is a silicate-free, orange coolant designed by GM to last 5 years or 150,000 miles. It's a great advancement in engine and coolant technology; however, the early engines that used this coolant developed problems with their gaskets, pumps, radiators, etc due to various reasons and led to a huge class-action lawsuit that was settled last summer 2008. After doing some research, I've boiled the problems down to these few bullet points:

A) The gaskets were made of a plastic material that was incompatible with Dex-Cool. I am not sure if GM has changed the material with which they build their gaskets; if not, this problem might persist on new engines.
B) In extreme weather areas, Dex-Cool degraded faster than the recommended 5 years/150,000 miles, causing early corrosion and water pump and gasket failures.
C) For some reason, certain engines ran low on coolant without having obvious leaks (can't figure out why). In those cases, if the drivers did not top off the system (because they never checked it, out of trust in the extended life of the coolant), their gasket and water pump seals blew due to overheating.
D) Dex-Cool is incompatible with other coolants. Engines that got exposed to a mix of different coolants (e.g. flushed dex-cool and filled with green coolant) developed sludge and early corrosion; that is because the flushing procedure was not thorough and residues of old coolant remained in the engine. Needless to say, if you mixed different coolants out right, you were toast.

I'm sure there are other reasons for the controversy surrounding Dex-Cool but I'm just going to ask a few questions for the future in hopes of getting some help from the experts around here. I plan on keeping this car for a long time and don't want to have to sell it at 100K miles! (I kept my Grand AM for 13 years but sold it at 100K miles out of fear of these problems)

1) Has GM changed the gasket materials to be compatible with Dex-Cool?
2) Has anyone used the Voltmeter test (http://www.getahelmet.com/jeeps/maint/dexcool/) or a Refractometer to measure the state of the coolant?
3) My most important question: flushing and filling the system:
a) Regardless of the tests in 2) above, I plan on changing the coolant every 2 years; will it void my warranty?
b) My goal is to thoroughly flush the old coolant out and run distilled water 2-3 times in the system until it comes out clear; then add pure Dex-Cool to the residual distilled water until I get a 50/50 mix; then top off with pre-mixed 50/50 Prestone Dex-Cool. I know that no dealer will put up with this shit so I plan on taking it to my friend who is a mechanic. My question is: how can he run distilled water in the system until it clears out all old coolant??

Cheers
 

·
Registered
Joined
·
292 Posts
Soooo, what should I do?

Alright people, I know I'm bringing this thread from the dead but I've searched the site and still have not gotten a decent understanding of the best course of action to take.

I need to do a coolant flush, but my question is if 'dexcool' is shit, which coolant should I use? Or should I just put dexcool back in because GM probably fixed the issue with the seals/gasket? (I have a 2005)

This is also important because the Lube-X here in town broke their machine and isn't going to fix it. That means I have to drive 3 hours to the city to get it changed. Needless to say I want to now what the hell I'm talking about when I get there.

Thoughts, insight, anything you can add to the discussion will help. Has anyone done this, if so did you do it yourself or take it to a shop? Thanks
 

·
Registered
Joined
·
292 Posts
oh and another reason why this is important is because it was almost -40 degrees here this past week. That's where Celsius and Fahrenheit meet.
 

·
Registered
Joined
·
292 Posts
****bump****

nobody????
 

·
The G6 is my DD :-)
Joined
·
22 Posts
Seems to me that if you ask anything more difficult than "how do I change floor-mats" on this site, you've exceeded the mechanical knowledge of the group.

To answer your questions: stick with Dex -- gasket and sealing problems were solved a long time ago, and any issues were much less pervasive than the Interweb might have you believe.
 

·
Fried like a Cheese Stick
Joined
·
1,035 Posts
I had a major cooling system failure on my 2005 Grand Prix at about 50,000 miles. Never gave it a thought until a dire DIC warning came on about SYSTEM TOO HOT or something like that and then noticed the temp gauge was pegged. Checked my Scanmaster (GP's version of the DashHawk) and the temp was 236 :eek: Pulled over as soon as I could and found just sludgy gunk in the overflow
Got to a store and got some regular Prestone as a stop-gap measure.

Temps came down to normal and I arranged for a local garage to do a flush. They said it needed 2 to get everything out :p They of course refilled with DexCool as recommended.

On the Grand Prix boards DexCool was pretty much universally panned, and Zerex's version was recommended. It took me a while to find some around here, but after I did a more mechanically minded friend and I did another flush & fill ourselves.

Didn't have any issues after that, but I sold the car with 62,000 miles so who knows what joy the current owner is now experiencing a year and a half later
 
1 - 6 of 6 Posts
Top