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**showtime** · Dec 2, 2005, 12:45 PM

I'm not too impressed with that stuff either. I believe Prestone makes some that can be used with either red, green, or yellow coolant. You could do a flush yourself and replace it with that. If you change colors with out getting it all out of the system you can screw things up.

**gb387** · Dec 2, 2005, 01:37 PM

Here is a post on DexCool:

From: http://www.penray.com/bulletins/dexcool.htm
Category: Coolants
Bulletin No. 01.010
Date: 01/12/01
Replaces: 96.009

Introduction:
Equilon (owned by Texaco® and Shell®) markets a European coolant technology (OAT) that consists of ethylene glycol inhibited with a combination of sebacic acid and 2-ethylhexanoic acid supplemented with tolyltriazole. It was originally called "Long Life", but a lawsuit brought by Warren Oil, who markets a fully formulated coolant under the brand name "LongLife®) forced the retraction of that term form the DEXCOOL, Texaco and Caterpillar® packaging. The combination of a mono and dibasic carboxylic acids permitted Texaco to obtain a patent on the specific combination. Other companies have obtained similar patents, by varying the mixture somewhat and by using similar, but not exactly the same, chemistry.

General Motors® has been using this coolant technology in their cars and light trucks since the start-of-production of the 1996 model year vehicles (except Saturn®, which began in 1997). GMC® medium trucks equipped with Caterpillar engines, have been getting a nitrite-added form of DEXCOOL (NOAT) to insure protection against wet sleeve liner cavitation-erosion.

Frequently Asked Questions:

Can DEXCOOL organic acid antifreeze be mixed with ethylene glycol antifreeze?
It is ethylene glycol based antifreeze! The concern with mixing comes from the fact that there are very different chemical inhibitor packages in use. Most leading technologies will work very well when used as intended, typically at 50% in good quality water. If the coolants become mixed with DEXCOOL, however, one study showed a possible aluminum corrosion problem in certain situations. The other question is a concern for dilution of the protection packages. At what mix is the there too little of either inhibitor to protect the engine? As a precaution, both GM and Caterpillar instruct that contaminated systems must be maintained as if they contained only conventional coolant.

How long will it last?
Uncontaminated, the engine manufacturers instruct that it may be kept in service for 5 years or 150,000 miles in cars. In trucks, Caterpillar and GM currently recommend that the nitrited version of the coolant be run 300,000 miles or 2 years, re-inhibited with a nitrite-tolyltriazole "extender", and run to a total of 600,000 miles.

Are there different brands that meet the spec?
Yes. Any brand displaying the DEXCOOL trademark meet the spec, others advertising compatibility are from the same family of coolants.

How can a customer tell if he has DEXCOOL?
If the customer owns a GM car and has orange coolant, then its DEXCOOL! In GM trucks the coolant is "orange- red", indicating that it contains nitrite. Orange coolant in Daimler-Chrysler® vehicles is NOT Dexcool. (Daimler Chrysler owners with orange color factory coolant should consult their owners' handbooks).

Does it protect aluminum?
Yes, even though it contains no silicate, the primary aluminum protector in conventional antifreezes, published data shows that it protects aluminum.

What are the advantages of DEXCOOL compared to the previous GM 6043 factory-fill?
Compared to old-fashioned phosphated antifreeze, it may be more stable and improve water pump life. Evaluations of the two technologies to compare their respective service lives has found them comparable. In fact, a Ford Motor Company study concluded that organic acid coolants do not offer any significant advantages for the consumer over current North American coolants. In a modern car with a well maintained cooling system, current North American and OEM factory fill coolant corrosion protection can be extended far beyond previous expectations."1

What are the disadvantages?
Higher cost, possible incompatibility, limited availability.

Is it environmentally safe?
It is ethylene glycol based. It is toxic. While it does reduce coolant waste, it is not environmentally safer than conventional EG coolant.

How can you test it?
Use a refractometer to test the freeze point. The inhibitor levels can not be cost effectively tested. If in doubt, throw it out and start over.

Should we recommend that Pencool® 2000 or Pencool 3000 be used with Dexcool?
Penray does not recommend the use of Pencool in Dexcool coolant.

Pencool® is a registered trademark of The Penray Companies, Inc. Dexcool® is a registered trademark of GM.

You know if Caterpillar allows its use in their engines it can't be that bad?!?! I had it in my 2000 S10 Xtreme, owned it for 4 years, never had a single problem... it did the job!

You hear good and bad about all kinds of coolants, doesnt' mater the type, just go with what works for you.

Some say you can flush and change over some say you can't, some say it will gum up some say it won't. Some say it eats gaskets some say it doesn't. I have not found any reliable info on this, just what various people say. This quote above just talks about Dexcool answering some q's.

**Tom Weed** · Dec 2, 2005, 01:45 PM

Thanks GB387 for that information and showtime. Problem with doing it myself is I dont think you can really get it flushed clean without pressure? Also I my car has only 23K miles on it and that stuff is like paste already in places. Maybe it was bad batch or something.

Tom

**gb387** · Dec 2, 2005, 01:53 PM

Originally posted by Tom Weed
Thanks GB387 for that information and showtime. Problem with doing it myself is I dont think you can really get it flushed clean without pressure? Also I my car has only 23K miles on it and that stuff is like paste already in places. Maybe it was bad batch or something.

Tom

If you really start searching around it can be a controversial subject!?!? I find it hard to get good info about it. Just my .02.

**Pete-FWA** · Dec 2, 2005, 03:56 PM

Originally posted by gb387
If you really start searching around it can be a controversial subject!?!? I find it hard to get good info about it. Just my .02.

Yes, I agree. First, so many people don't understand Dexcool. Next, no one is sure if it really DOES last much longer or give any other benefits.

Just last week, I had a friend who owns a service shop tell me that they've had bad luck from it and, when flushing cooling systems, are recommending to owners that they switch back to old-style phosphated antifreeze.

**gb387** · Dec 2, 2005, 08:12 PM

Originally posted by Pete-FWA
Yes, I agree. First, so many people don't understand Dexcool. Next, no one is sure if it really DOES last much longer or give any other benefits.

Just last week, I had a friend who owns a service shop tell me that they've had bad luck from it and, when flushing cooling systems, are recommending to owners that they switch back to old-style phosphated antifreeze.

You could ask 10 different guy in the same shop and get 10 different answers.... I have no problem with that, its what makes you happy.

Several years ago I started to dig deeper into this subject after a question came up on Extended Life coolants/mixing and so on, I think after all the reading I was more confused. IMO (this is about the only thing I have found most agree on) no matter the type of coolant you use, stick with the same type don't mix them. Manufactures of the coolants and vehicles tell you not to mix them, I would guess they have done tests and seen problems one in the post above points out corrosion.

**Setec Astronomy** · Dec 3, 2005, 04:04 AM

I have it on good authority that a long time ago (20 years) every car out of the GM Linden, NJ assembly plant received a dose of flax seed/aluminum powder radiator sealer, "just in case". If that kind of thing is still going on, it may be that radiator sealer is what is gumming up the works in your car.

As far as the Dexcool, there was quite a bit of controversy about this gumming, some blaming it on people not keeping the radiator full which allowed the gum to form and screw up the check valve function of the cap, exacerbating the problem.

The extended life Prestone (not their Dexcool) has some patented additive combo which makes it compatible with all coolants, and it has the extended drain interval if added to an extended-life coolant. So if you do just a drain of your Dexcool, without a big-deal flush, you can just refill it with the Extended Life Prestone and maintain the 5 yr/150K miles and not have Dexcool worries.

My recollection is that the Prestone site used to have a lot more technical info, but here it is: http://www.prestone.com/products/antifreezeCoolant.php

**Aurora40** · Dec 3, 2005, 05:57 AM

Originally posted by Tom Weed
Thanks GB387 for that information and showtime. Problem with doing it myself is I dont think you can really get it flushed clean without pressure? Also I my car has only 23K miles on it and that stuff is like paste already in places. Maybe it was bad batch or something.

Tom

23k miles is probably not the issue. Your 2003 MY car is probably 3 years old by now. As said, it may be the coolant supplement tablets added that are gummy.

If it were my car, I would have the system flushed by machine with nothing other than 50/50 Dex-Cool to remove any crud in the system.

I would continue to use Dex-Cool in a car that came with it. But it's your car, so it's ultimately up to you.

**Tom Weed** · Dec 3, 2005, 06:14 AM

Thanks everyone for the opinions and advice, gave me some things to think about...

My first thought today was to go to the local Pep Boys and buy some Radiator flush, and some Dex-cool, but I was reading about Prestone Extended life that could be added or used with ANY coolant. I thought if something did happen, I would be on my own. Plus I don't really have a good place to get rid of the old stuff and it's not going to be above freezing today here.

I will probably just go to the local oil change place today and since they have a machine, have them flush it and try the Dex-cool again.

Tom

**Aurora40** · Dec 3, 2005, 06:20 AM

Be aware with those flush things. On many cars only half or less of the total coolant will drain out. So if you use a DIY flush, you will quite possibly have flush chemicals in the engine that you can't get out. A machine that pumps through properly mixed coolant should be able to remove the crud while leaving behind the proper ratio of stuff you want in there.

I think most of those flush machines can pump through like 5+ gallons of coolant, more than enough to displace all the old stuff.

Just make sure those Jiffy Lube folks are doing the right thing. Don't assume they know what is best for your car.

**Djmigs** · Dec 3, 2005, 09:06 AM

i think most antifreeze are hype or marketing just so you can buy there brand i would stick with the normal service interval for your particular car no matter what brand and price......just use what you feel works for you.....i would either find out what they put from the dealer and use that or if its a rebrand find out or you can for example if you have a chevy cavalier find out what they use for corvette and use that(so what ever car you have use the antifreeze for the high end/performance cars if that gives you a piece of mind)...just a thought...

**Djmigs** · Dec 3, 2005, 09:07 AM

by the way i did forget to add yes flush by machine your oil and your antifreeze once a year if not once every two years ...just a suggestion

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