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A growing uncertainty about Dexcool

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Old Jul 31, 2003 | 07:53 PM
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Default A growing uncertainty about Dexcool

I was watching the news last night and something about it caught my eye. They were doing a report on Dexcool - GM's orange water treatment that is supposed to be good for 150,000 miles. Well see for yourself by clicking on the link:

http://abclocal.go.com/kgo/news/7oys...s_dexcool.html

It was horrendous to see what happens to Dexcool when subjected to engine heat - it literally turns into mud.

I was talking to my boss today and the talk drifted to car repairs. He said he hates Chevy for a ton of screw-ups that they had done to his car and how mechanics do not listen to him when he tells them the problem of his car. (He got a brand new clutch assembly for free including labor coz they did not listen to his complaint that his axle was broken). He said that 2 of his cars had the "soft plugs" *he went into detail what they are* in his car changed due to cooling system failure. This guy is a car guy, literally living in his garage making sure all his cars are in top shape. He never had an under filled radiator. He's a manufacturing manager, nothing but "within spec" for him.

Then the report I saw last night clicked on me and I told him that he must be using the orange stuff in his car. It was a Corvair and I believe an Astro Van that got both the same problems. No wonder he dropped Chevy and now owns two 911s and a 933.

On my way out of the company, I talked to a friend who races his 2002 Z06 and said that he gave up on Dexcool and uses a ratio of water wetter and water for his Z06. He had his stock radiator changed with a higher efficiency one (Rippie?) and a 178 T-stat. He races this car (Pony Express, Silverstate, etc) and says that this setup is more favorable to him as even his mechanics recommeded this and stay away from Dexcool.

What do you guys think? I probably drain my dexcool on the weekend and try water and water wetter in the meantime. If it's good enough for a Z06 that sees street and strip on a daily basis, I think I would follow suit.



[Modified by c5chris, 4:58 PM 7/31/2003]
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Old Jul 31, 2003 | 08:08 PM
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Default Re: A growing uncertainty about Dexcool (c5chris)

At 63,000 miles I decided to change my coolant for the first time. Instead of waiting the 5 yrs or 100,000 miles. There were already signs of dexcool sludge. Not even a month after changing the coolant my water pump bought the farm.

Looks like the sludge build up that was attached to the walls of the radiator broke loose after having new coolant in the system. This sludge was kind enough to kill the water pump. :mad
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Old Jul 31, 2003 | 08:13 PM
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Default Re: A growing uncertainty about Dexcool (c5chris)

I changed mine at 5 years and 50,000 plus miles. It was so clean I didn't even bother flushing. I drained out all but 1 -1 1/2 quarts.

I understand it is okay unless you develop a leak and air gets into the system.
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Old Jul 31, 2003 | 08:14 PM
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Default Re: A growing uncertainty about Dexcool (c5chris)

A local mechanic hosts a Saturday morning talk radio show on all things automotive including diy repairs. He rants almost every week on the importance of not letting Dexcool go for longer than 2 yr/30k mile intervals. He claims the coolant becomes acidic after 2 yrs and begins to chew away at gaskets. Also, he claims it does turn to slug.

I'm on a 2 yr interval plan on the Vette. It's much cheaper to change the coolant than it is to repair problems caused by the coolant.
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Old Jul 31, 2003 | 08:14 PM
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Default Re: A growing uncertainty about Dexcool (c5chris)

Is there a Dexcool compatible coolant that will work better?
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Old Jul 31, 2003 | 08:22 PM
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Default Re: A growing uncertainty about Dexcool (allanlaw)

Many german made cars use a similar coolant and have no problems at all.

VW coolant is now G12-80, kind of pink-orange stuff. It's a similar kind of OAT coolant. I've personally seen cars with over 200k miles with this stuff have absolutely no issues with sludge. They just decided to change a water pump at the same time as the timing belt as a pre-emptive service measure. Drained the coolant, pulled the pump and it was clean as a whistle.

My guess is GM decided it was a good idea, then squeezed the vendor for every penny. I've heard mixed reports on Dexcool. In many cases, sludging has been traced to contamination from other anti-freeze added to the reservoir or even bad/poorly designed caps that allowed dirt and crud to be sucked into the tank as the engine cooled.

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Old Jul 31, 2003 | 08:32 PM
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Default Re: A growing uncertainty about Dexcool (c5chris)

Are testing our car knowledge. :confused:

Everyone knows the Corvair was air cooled. :lolg:
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Old Jul 31, 2003 | 08:45 PM
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Default Re: A growing uncertainty about Dexcool (w8d4it)

Sorry, I must had misunderstood this part for some reason. ;)

With a list of his Chevy cars (CORvette, CORvair, Chevelle, Chevette, :crazy: ) I probably got lost

Thanks for the correction. :cheers:
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Old Jul 31, 2003 | 08:49 PM
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Default Re: A growing uncertainty about Dexcool (c5chris)

My dex cool at 35K and 3 years had a sediment visable in the coolant tank.
Flushed and re-filled w/ dex.

Water wetter and pure water is good for cooling, but I understood that aluminum engines could use some type of chemical protection that anti freeze offers.
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Old Jul 31, 2003 | 08:51 PM
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Default Re: A growing uncertainty about Dexcool (w8d4it)

This is not a Dexcool problem, it is a maintenance problem. GM and Texaco did a joint study a couple of years ago and presented the results at an automotive symposium. The root cause of all the problems was low coolant, period. It isn't mixing it, or anything else. There is no way I am going to believe some bozo newscaster and a couple of lawyers out for $$$$ (I will stop there).

Do some research on Dexcool and check the chemical properties and compare to other coolants. Don't listen to hearsay and other goofy information. I switched all my cars to Dexcool years ago, no problems. I even went to the extreme of going inside my 90 Corvette with a boroscope and found the block and radiator to be extremely clean and free from any corrosion. I personally think it is one of the best coolants out there, you just need to keep the system full. When is the last time you think that woman on the newscast checked her coolant level (can you say never). And her dealer, with all the information provided by GM on Dexcool to keep an eye on the level, I would be willing to bet they never checked it either.

Now for the final issue. That motor looked like the 3.1 V6 when she briefly opened the hood. They are known for leaking at the intake, and it's not Dexcool because mine leaked with green coolant, it is the gasket design. I have since switched my 3.1 to Dexcool and have had not had a re-occurance or other problems.
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Old Jul 31, 2003 | 09:08 PM
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Default Re: A growing uncertainty about Dexcool (vettenuts)

...I personally think it is one of the best coolants out there, you just need to keep the system full...
:iagree:

...the 3.1 V6 ...are known for leaking at the intake...it is the gasket design...
I believe the 3.4's are the real culprits for the leaking intake gaskets, I don't think it is even half as bad on the 3.1's. :)
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Old Jul 31, 2003 | 09:22 PM
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Default Re: A growing uncertainty about Dexcool (vettenuts)

Vettenuts,
I agree with you. I have a 98 with over 100K on her and the cooling system is clean as a whistle! I just finished the second flush and refill.. The first time at 50K, I went to the 178 T'stat and a 70%water 30% Dex cool mix with water wetter. Is that like a bed wetter, I digress! :jester Anyway I just finished the 100K Service and still spanking clean and went with the same mix. I must admit that on my wife's Blazer she let it get low once and wham I could see the sludge start in the tank. I immediately cleaned/flushed and refilled the system with the same I have in the vette. The system was clean, just the tank had the sludge where it went dry. Oh yes the water I used was that electronic pure distilled stuff. I insist on absolutely pure water.

A lot of people (Not Vette people) tend to think the car will run forever, just put gas and oil in and you are good to go! They forget about the high mile maint, and the other stuff. I wonder how often people change their brake fluid and transmission fluid. Willing to bet some big money you will get a lot of nevers on those two. and a lot more if you throw in the rear end, what about the power steering, anybody service that?

By the way my wife is one and my oldest daughter is also. My oldest cost me a complete motor in a car I got for her. She ran it dry on coolant, and kept right on going! It threw a rod, then stuffed another rod through the side the block. The only thing left for a good core charge were the heads and intake manifold. Actually i have seen racing engines go with less damage!

Ya just got to be careful and look at the whole picture, sometimes things ain't what they seem!

Jer
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Old Jul 31, 2003 | 09:32 PM
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Default Re: A growing uncertainty about Dexcool (c5chris)

The Vette has been fine so far but I also have a 96 Impala SS with about 50k on it and I have already replaced the water pump last year and the radiator a few months ago :mad
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Old Jul 31, 2003 | 09:54 PM
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Default Re: A growing uncertainty about Dexcool (C5Coup)

I just did a H/C swap. The dexcool had 55k miles on it and looked brand new.
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Old Jul 31, 2003 | 10:23 PM
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Default Re: A growing uncertainty about Dexcool

Don't forget to use distilled water and not tap water.
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Old Jul 31, 2003 | 10:56 PM
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Default Re: A growing uncertainty about Dexcool (H82BFST)

Don't forget to use distilled water and not tap water.
I agree with the distilled water thing too. It's really cheap and is good insurance. Just serviced mine at 77K (first time) and it was pretty clean. Just a small amount of crud in the overflow tank. It cleaned up pretty good. Changed all the hoses (radiator and heater) and the old ones were very clean.

Robert
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Old Aug 1, 2003 | 12:02 AM
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Default Re: A growing uncertainty about Dexcool (c5chris)

I just sold my '99 Trans AM with 95K miles on it, but before I did I checked EVERYTHING on or in the car to make sure any buyers "in the know" couldn't talk me down off the price because of poor maintenance. The DexCool was absolutely PERFECT. I've read a lot of complaints about it, but I've also heard that the biggest problems are caused by contamination getting into your system. If you get your oil changed at the local shop in front of the grocery store for $19.95, the kid they're paying $7 an hour to do the work probably topped off your Dexcool with the regular green anti-freeze, that's a definite :nono: . I've even heard some mechanics say that Watter Wetter doesn't get along with Dexcool very well either, but most of the people who use it tend to drain/refill or flush their radiator often enough for it not to matter. I always use a 50/50 mix of distilled water and pure Dexcool, no problems so far, knock on fiberglass :D .
:cheers:
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Old Aug 1, 2003 | 01:03 AM
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Default Re: A growing uncertainty about Dexcool (markcz)

I think Dexcool works very well so far. Just changed the original dexcool out of my '99 and it was so clear and contamination free it looked like colored filtered water.
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Old Aug 1, 2003 | 01:08 AM
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Default Re: A growing uncertainty about Dexcool (markcz)

I have Dexcool in all 3 of my current cars and have not had a single problem with it. In the past year I traded a 99 Tahoe and a 97 C5 and did not have any problems with either one of them.

Do not believe every news cast. Most of them have the story screwed up from the time they start working it. Especially the local newspeople.

Haven't you ever been interviewed by one of them and then watched how they put the story together so it sounds completely different than what you were saying?

Bill

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Old Aug 1, 2003 | 01:13 AM
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Default Re: A growing uncertainty about Dexcool (Bill Dearborn)

Prestone makes a coolant that is Dexcool compatible. Why not just switch over and not worry about it anymore.
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