Distilled Water / Dexcool

[twiget]

Distilled Water?

Well, I checked the coolant in my GS, and found it to be a nasty brown color. It was filled with Dexicool, which has a habit of decomposing into what I just found. So, my question is, considering the aluminum radiator, would I be better off with distilled water or regular tap water when I change out the coolant?

Jason

 

[vms4evr]

Jason,
I flushed mine out a couple of months ago. And saw that same nasty looking color. Completely remove your overflow jug and hose that thing out. Mine was nasty...
I used Distilled water to make the mix. Not sure you have to but I'm on a well and have a fairly high mineral content so it was just added insurance.
Graham

 

[c4c5specialist]

Hithere,
Distilled water is very critical to the way Dexcool functions.
Yes, 50 50 mix, and pull both knock sensors if you can, pop the thermostat, and flush the engine with a garden hose.
Allthebest, c4c5

 

[Interceptor430]

If you are definately gonna continue using the DexCool - and it hasn't been changed/replaced in a while...I'd sure replace it all.
Dexcool that isn't changed/kept relatively fresh is being fingered as the culprit because acid develops in old Dexcool, and it is eating the gaskets causing intake leaks on many a Tahoe, Silverado, etc.....many many people are going back to the green stuff. Old dexcool is also reported to 'gel' inside the block and block or severly restrict the water passages....flushing out the jello is a real pain....
Now, I keep the green stuff in all of my rides.

 

[VetteGarage]

I ownd 2 1996 Jimmy's and have had major problems with both. The 2 door I just traded because I believe the intake gasket gave way (probably as a result of Dex Cool) and the crankcase filled up with anti-freeze. My 4 door has had the fluid changed 2 times and the heater core replaced. Mr. Goodwrench's mechanic botched up the job big time, and just last week I had to flush out the heater core again. When the weather get warmer, I will change all hoses, flush out the entire system and replace with conventional anti-freeze. Dex Cool Sucks!!

 

[Interceptor430]

VetteGarage....
yep....happened to my '97 Silverado too - at 73K miles...
I dumped that truck too.....and run the green stuff in my 2000
Silverado....
GM for sure won't own up to something like this....the recall would
be horrendous!

DEXCOOL

 

[VetteGarage]

My 4 door Jimmy has 52,000 and the 2 door I traded in had 62,000. GM would take no blame and the damn stuff says 5 years or 100,000. I think now they are "guaranteeing" it for 6 years and 150,000. Does not make much difference, they did not back it up before. Is there a difference in the Dex Cool they are using today, as to what they used in 1996?

 

[Interceptor430]

Good question ref the DexCool of today.....I think that question may remain unanswered directly. Otherwise they'd have to
admit something....so yea...maybe that's why they are now
saying this new stuff is a 6 year 150K fluid....BS!!!
Why on earth GM would want to advertise/plublish all of that
kinda verbage on stuff that that costs $6 a gallon is beyond logic!
I mean really! $12 bucks of fluid staying in there for 5-6 years
is 'Good News' for the consumer?....what a crock! - but hey - be sure and change the oil every 3K miles because oil is the life blood of an engine....but don't worry about the other fluid running thru your engine for 5-6 years?.....
Amazing!!!!!!!!!!
Yep...Dexcool....jello in the making, seal eater, more $'s for the Service Department - and/or good for making people become disgusted and trade for a new one(like I did).
Just check out all the stuff said about this crap on the
Tahoe and Suburban forums....

 

[twiget]

I was considering changing the dexicool to Prestone, or something else, but now that I've heard what you guys have to say about it, it's definately going to be done.

The raidator was replaced about 16 months ago due to a puncture from road debris, and was filled with dexicool then.

My '86 K5 Blazer has a rebuilt 305 with an aluminum radiator that was flushed last year due to bad dexicool, and is going to get it again for the same reason.ad

Hopefully this crap has not done any perminate damage to the seals...

Jason

P.S. how much coolant do I need?

 

[Interceptor430]

Jason.....looks like we(me) have hijacked this thread - but based on the thread heading - I was thinking many people may not be getting the word ref the Dex....
can you do something there?...with your Admin power...
seems to me many others might want to know/chime in on this sub....

 

[evolution]

It seems that the minerals in ordinary water reacts when it flows through both aluminum and iron. Distilled water does not contain those minerals and will help keep coolant clean.

Sorry if anyone else mentioned this, I was lazy and did not read all of the posts

 

[Carrot]

Yep...

Plain tap water with dissolved minerals and particulates provide activity for corrosion to take hold, and if the water is hard, it will also just plain clog up the drain with mineral deposits.

Has anyone thought about using the new 'lazy man' products, the premixed 50/50 that's showing up in auto stores now?

 

[twiget]

Jason.....looks like we(me) have hijacked this thread - but based on the thread heading - I was thinking many people may not be getting the word ref the Dex....
can you do something there?...with your Admin power...
seems to me many others might want to know/chime in on this sub....

It has been done.

Jason

 

[c4c5specialist]

Hi there,
If I may, there is alot here that is not being mentioned.
99-06-02-012d is the listed service bulletin for the Blazer fiasco that plagued alot of them with Dexcool breakdown and sludge buildup.
This was traced to untreated water added to Dex cool at the factory.
Those whom attempt to use Dexcool on a system originally using normal green coolant will still have to change it every 2 years/24k miles. This is because you can never flush the green coolant completely from all the pores in the aluminum, cast iron, and steel. That contamination is what breaks down the Dexcool.
The fact of the intake gasket leakage on 4.3, 5.0, 5.7, 7.4 and the like are due to overtorqued gaskets, which cracked, creating the coolant leaks, and contamination of the engine oil.
There are also bulletins on this intake gasket problems.
The most important thing to realize about Dex cool, is that purity, and periodic checks are the most critical part of the formula with this.
Even though many will state otherwise, distilled water is what must be used, per GM service information, and 5050 mix, with NO cross contamination of green coolant in any way. You will never have the benefit of Dexcool when adding to a system run on green coolant. The contamination will not allow it.
I hope that this answers all your questions, c4c5

 

[twiget]

Hi there,
If I may, there is alot here that is not being mentioned.
99-06-02-012d is the listed service bulletin for the Blazer fiasco that plagued alot of them with Dexcool breakdown and sludge buildup.
This was traced to untreated water added to Dex cool at the factory.
Those whom attempt to use Dexcool on a system originally using normal green coolant will still have to change it every 2 years/24k miles. This is because you can never flush the green coolant completely from all the pores in the aluminum, cast iron, and steel. That contamination is what breaks down the Dexcool.
The fact of the intake gasket leakage on 4.3, 5.0, 5.7, 7.4 and the like are due to overtorqued gaskets, which cracked, creating the coolant leaks, and contamination of the engine oil.
There are also bulletins on this intake gasket problems.
The most important thing to realize about Dex cool, is that purity, and periodic checks are the most critical part of the formula with this.
Even though many will state otherwise, distilled water is what must be used, per GM service information, and 5050 mix, with NO cross contamination of green coolant in any way. You will never have the benefit of Dexcool when adding to a system run on green coolant. The contamination will not allow it.
I hope that this answers all your questions, c4c5

It would appear that most of the issues discussed in this thread about the quality of dexicool is due to poor installation, and misinformation, correct?

Other than dexicool being biodegradible and non-lethal, what other benifits are there over the green stuff?

Due to the fact that the dexicool has gone south on me twice in my truck, it's going to get Prestone this time. And to keep things simple, (and cause the dexicool has gone south in the GS too) I'm going to put Prestone in the GS. But it's always good to have the full picture.

Jason

 

[resto75]

What was the first year they used Dexcool in a Corvette ????

 

[secondchance]

I agree with c4c5specialist. My understanding is that once a car runs on silicate base coolant(green stuff), it would be impossible to flush it out. When Dexcool is run through the cooling system, Dexcool reacts with left over silicate and the end result is the guck you are describing.
I considered converting to Dexcool but backed off after reading a detailed description of the information I summarized above.

 

[Interceptor430]

A Service bulletin on the over torqued gaskets?....After 4 years and 75K miles and they say that?...I sure didn't hear any of that when the dealer quoted me a price of over $500 to fix the intake leak!!! Uh hu...all they wanted to service was my backside.

I still say....and no service bulletin can or will convince my back pocket otherwise...and the green stuff is the best - proven for years and zillions of miles, and there is zero logic to any newfangle coolant staying in a motor for the period of time that GM states on this Dexicool. $12 worth of coolant every 2 years
is alot cheaper than the $500 they wanted to fix my dexicool
jellied up 5.7.

Misinformation?...uh hu....it's your engine, do what you think is best - but don't get caught up with a problem because it was too expensive to shell out $12 every 2 years for a couple gallons of new green antifreeze.

Check the Suburban, Silverado, and Tahoe forums.....
Just beware of the hype, and do the right thing.

ok...I'm done.

 

[vettedoc]

What was the first year they used Dexcool in a Corvette ????

I would like to know the answer to this question too!

 

[SPANISHVETTS]

I have been using waterless coolant for several years. Go here http://www.evanscooling.com/index2.html and check it out.

It cost a bit more to start with but in the long run it can save you an overhaul.bash

I first started using NPG in my GoldWing because the thing only runs good at 218º regular coolant does not give you much reserve before it boils over. When ever I would nail the cruise control on the Wing to the 100MPH mark the Honda coolant would start to boil in about 20 min. With the NPG I can cruise all day with out any overheating.

Based on the Wing experience, I converted the Vette to waterless cooling as soon as I got her. I have not had any of the cooling problems that you folks post. I drive fast and cover lots of miles in extreme conditions. (+105º to -15º) The Vette has 105,000 and the Wing has 94,000.

With NPG I have never seen the Vette even close to hot.
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