This is a Vid Watt's made of a motor that blew a head gasket using dexcool. It is a 3.1 V6 roller motor. The stuff in that motor was nothing short of tar. Just look at it drip from one of the guys hands. I am sure watts can explain more.
http://www.david.westcoastfieros.com/dexcool&oil.wmv

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David hotrodfiero@shaw.ca
85GT 2.9 4spd

I doubt it was the dexcool that cause the problem, unless he just dumped the dexcool in there without properly flushing the system.

I'm using Dexcool in my quad without a single problem.

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1988 Quad 4 Coupe 5 speed
More pics of the coupe
1986 GT 5 speed, 1984 SC Auto
AOL: LastMinuteBastrd AIM: SavedbyJebus

The point is that when dexcool mixes with oil for any reason, it becomes a sludge that is more tar like and gooey than you can really belive. Oil and water will turn into a milkshake and even seperate to a point but this new GM Dexcool is pretty bad stuff. I personally would not want the stuff within 20 feet of my car. If it had some benift like it cooled a ton better or had less drag going though the cooling system I could see using it, but if the only thing that it is good for is so you do not have to flush your cooling system, No thanks. As I flush my system every year.

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David hotrodfiero@shaw.ca
85GT 2.9 4spd

It does about the same thing when it comes in contact with any remaining ethylene glycol based antifreeze. Not something you would ever want to switch to (or from), as its pretty hard to get every last bit of old antifreeze out of a block before doing so.

Dexcool is better with mixed metals (alloy heads/iron blocks) IIRC. Also a heck of a lot better for water pump seals. Better corrosion protection.

Also, if oil is mixing with the coolant your gonna have problems anyways...

air and dexcool don't like each other... if you've got the same problems everyone else does burping a fiero.. and have ANY air in the system, the Dexcool will RAPIDLY break down. Turns to sludge. It should mix fine with standard coolant, just looks brown due to mixing dies and you lose the long life they claim. but contamination with air is a bad bad thing.

That video is showing the results of coolant entering the oil system... that is NOT the coolants fault. Oil/coolant mix equals diahrea in the oil pan as shown, but it's not the coolants fault it got there. Something caused the headgasket to blow or block or head to crack.

What is the rest of the story?

Have these guys informed the customer that just wants it cleaned up that the bearing are toast? Coolant EATS bearings... engine needs a complete teardown, inspection and rebuild, with exception of gaskets and bearings, probably can use the rest with 3k miles on it, but I'd recheck EVERYTHING to determine why it failed.

[This message has been edited by Scott-Wa (edited 08-06-2002).]

Never heard of any issues with air, at least not different than normal anti-freeze. Did have some problems with old EG anti-freeze left in a block though, and I can assure you they do not mix well.

[This message has been edited by 00lE (edited 08-06-2002).]

I can tell you that dexcool definately does not like air in the system. Air breaks it down. Air in the cooling system is main reason for most modern cooling system failures and especially GM ones using dexcool. We've discussed this issue ad nauseum on iATN (international Automotive Technicians' Network)for years now. There are quite a few TSB's out covering various issues with Dexcool. It has advantages, it just is not the magic pill the advertisers promoted it as when it came out.

Well, just because I've never heard of it does not mean its not a fact. I like to think that if I try hard, I can learn at least one new thing each day. Thanks for the info..

I've been working with dexcool for awhile now and I can't say I like it. If you look at the rad of a 1996 blazer, the inside is coated in a thick red coating. Probably not bad as it looks but I'm thinking long term buildup. There is always corrosion on the cap. As far as I know it can mix with the green coolant because basically its the same thing. Dexcool has a group of additives called Organic Acid technology that stabilizes it for longer term. The only advantages I know of are for cars with aluminum heads etc.. because its formulated for it. Every car maker has their own version now. Its rated for 5 years or some 200,000 kms, replace it by time, not mileage and it will fare better.

Trev

my inlaw bought a 89 chevy truck with dexcool in it with over 160,000 miles on a 350 sb. radiator has never been flushed. brown stuff all over, everwhere. when we flushed it out it left this nice brown stain on the driveway. took half a day of running water through the radiator and bottle to get the crap out. looked kind of like rust. can't imagine what the block looks like.

Why did they mix oil and dexcool???? Why did they say that there was so many liters of a combination of oil and dexcool. Sounds like more of a problem than just the use od Dexcool to me.

let's clear the BS here.

First off, DUH oil and water bad. That's what blew his HG.

Second, DexCool and the green stuff will mix fine, the corrosion inhibitors in DexCool will not work as well though (treat like green stuff.)

DexCool is designed to run with BarsLeak tablets in many modern aluminum engines. Peroid. 'New' (like 30+ years old) tech, get used to it allready.

Last, DexCool should still be replaced often, and the 5/100,000mile is a whichever comes FIRST sort of thing... (so it's usually going to be time.)

Other than new inhibitors, it's EG with a dye.

Best!
Ben.

quote Originally posted by Capt Fiero: This is a Vid Watt's made of a motor that blew a head gasket using dexcool. It is a 3.1 V6 roller motor. The stuff in that motor was nothing short of tar. Just look at it drip from one of the guys hands. I am sure watts can explain more. http://www.david.westcoastfieros.com/dexcool&oil.wmv

------------------

Ben Cannon
88 Formula, T-top, Metalic Red. (2:13.138 at Sears Point) "Every Man Dies, not every man really Lives"
88 Formula, Northstar, Silver, In-Progreess. -Mel Gibson, "Braveheart"

quote Originally posted by artherd: Second, DexCool and the green stuff will mix fine, the corrosion inhibitors in DexCool will not work as well though (treat like green stuff.)

I've heard lots of different places to NEVER mix the two. Not trying to argue, but I'd rather err on the safe side and just keep Dexcool in my 99 Grand Am that came with it and Green EG in my Fiero.

I've got 100,000 mile tune up schedule and the 5year / 100,000 mile coolant in my GA. Then why does my dealership tell me I need a tune up ever 36000 miles and new coolant every 12mo/12K miles regarless? Mfg. makes the claims for advertising, dealers make the recommendations for income. Is either one really accurate?

quote Originally posted by artherd: let's clear the BS here. Other than new inhibitors, it's EG with a dye.

No, Dex-cool is a "propylene glycol" based antifreeze with OAT (organic acid technology) type inhibitors rather than the older silicate based type. You should get your facts straight before you make a post like this.
Although PG is misible with EG, the pH is of Dex-cool differs from that of standard EG antifreeze, and when combined with "old" EG based antifreeze, precipitates form which cause a nice deposit of goo on the metal surfaces of the cooling system.
The OAT inhibiting system is quite pH dependant, and the alkaline pH of conventional silicate inhibited antifreeze can actually neutralize the OAT protection system if present in sufficient quantity.

HAAACHOOOOOO!

quote Originally posted by 00lE: No, Dex-cool is a "propylene glycol" based antifreeze with OAT (organic acid technology) type inhibitors rather than the older silicate based type. You should get your facts straight before you make a post like this.

TIME OUT !

FACT: Dex-Cool is an Ethylene Glycol based coolant and has the same excellent anti-freeze and heat transfer capabilities of other standard Ethylene Glycol based coolants.

FACT: Dex-Cool contains unique corrosion inhibitors, which are different from anything else on the market. Dex-Cool is vastly superior to conventional coolants, which use silicates, phosphates, borates, nitrites, nitrates, and amine additives to eliminate corrosion. These additives are abrasive to water pump seals, and silicates are especially unstable and drop out of solution and form a gel after time. All of these conventional inhibitors deplete after a short time, which is why conventional coolant must be changed every year.

FACT: The unique corrosion inhibitor technology in Dex-Cool is based on the use of two organic acids, which are synergistic and combine to form carboxylates. Texaco refers to this as Organic Acid Technology (OAT), or Carboxylate Technology. The corrosion inhibitors used in Dex-Cool deplete very slowly thus eliminating the need for traditional additives, or frequent change intervals.

FACT: Sta-Clean, AmSoil, Seafit, Peak Sierra, and Prestone LowTox Antifreeze are formulated with propylene glycol. Propylene Glycol Antifreeze is less toxic and therefore safer for people, pets and wildlife than conventional Ethylene Glycol Antifreeze. Two ounces of Ethylene Glycol Antifreeze, which can be appealing to animals because of its sweet smell and taste, can kill a dog; one teaspoon can be lethal to a cat; and two tablespoons can be harmful or even fatal to a child.

Don't want to start a Flame War here, just want to set the facts straight.

You must flush any trace of Ethylene Glycol Antifreeze from a cooling system before converting to Dex-Cool Antifreeze. Air CAN NOT enter the system with Dex-Cool Antifreeze. One of the most overlooked portions of an older cooling system when converting to Dex-Cool is the Expansion Reservoir. You need to install a reservoir with a pressure cap to keep air out of the system. The original Fiero Expansion Reservoir and overflow hose will not work. The reservoir and hose from a 98 Pontiac Sunfire works great.

[This message has been edited by ProudGT (edited 08-06-2002).]

quote First off, DUH oil and water bad. That's what blew his HG.

Now I might be wrong, but didn't the oil and water mix BECAUSE the head gasket blew, and not the other way around?

I just experimented with some Dex-Cool and Prestone Antifreeze.
Three cups of a 50/50 mix of Prestone and Water mixed with a 1/3 cup of 10-30 weight Mobil 1 oil went into my Oster Blender. Looked really bad when mixed at the highest speed for one minute. Looks like a thin green milkshake.
But you should see the 50/50 mix of Dex-Cool and Water and Mobil 1 oil.
What a difference!
If you want to really see what a bigger mess it makes, try it some time. It turns into a big blob of brown crud and is almost impossible to clean out of the blender.

[This message has been edited by ProudGT (edited 08-06-2002).]

as said before, if you have coolant mixing with oil you have bigger problems to worry about.

Given the FACT that Dex-Cool is nothing more than a trademark and spec licensed from GM by various antifreeze manufacturers, Havoline and Prestone to name a few, it could actually be based on either PG or EG. But, the materials I have dealt with have ALL been PG based.
BTW, I am an ACS certified analytical chemist, so I am pretty sure I know the difference

[This message has been edited by 00lE (edited 08-06-2002).]

Here's a link to a thread on the ls1 forum that
also discusses this topic. Has some interesting
info.
http://www.ls1.com/forums/showthread.php?s=&postid=1197623&highlight=dexcool#post1197623

Orville

Hey Mr Chemist.... Maybe you should learn to read a MSDS...

Source: https://thegenesisnetwork.equilon.com/GenesisASP/MSDS_External/MSDSInit.asp?strBrand=T&Letter=H (copy and paste it to the address bar.)

<copy start>
--------------------------------------------------------------------------------
SECTION 1 PRODUCT IDENTIFICATION

--------------------------------------------------------------------------------

MATERIAL IDENTITY: HAVOLINE® Extended Life Anti-Freeze/Coolant

PRODUCT CODES: 07994
COMPANY ADDRESS: Equilon Enterprises LLC, P. O. Box 4453, Houston, TX.
77210-4453

--------------------------------------------------------------------------------
SECTION 2 PRODUCT/INGREDIENTS

--------------------------------------------------------------------------------

CAS# CONCENTRATION INGREDIENTS
Mixture 100 %weight Extended-Life Antifreeze Coolant
107-21-1 90 - 96.99 %weight Ethylene Glycol
3164-85-0 1 - 4.99 %weight Potassium 2-Ethylhexanoate
7732-18-5 1 - 2.99 %weight Deionized water
<copy end>

Others, read the DexCool article at IMcool.com (It's liked to he coolant article in my cave.)

DexCool isn't a bad product but I still don't recomend people convert to it.

The biggest problem is that you can't flush out allot of stuff from the system. There is always crap left clinging. Given the DexCool is fairly easy to contaminate, this more often than not puts you on a bad start right from go with a conversion. If you screw up with this stuff you can have the kind of mess in the begining of this thread. Very bad.

The only time I would even consider such a conversion is with a fresh rebuilt motor that was completely tanked durring rebuild. Plus a new radiator and heater core. Plus a thurogh cleaning of the coolant pipes. Even then you'll have to watch out for crap getting in the recovery bottle etc... The recover bottle can collect an amazing amount of trash.

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11-Sept-01, The day the world as we knew it ended.

[This message has been edited by theogre (edited 08-06-2002).]

quote Originally posted by ProudGT: I just experimented with some Dex-Cool and Prestone Antifreeze. <snip> It turns into a big blob of brown crud and is almost impossible to clean out of the blender.

Oh yeah, I was speaking with your wife a few minutes ago, and she says that YOU get to keep the blender now in the impending divorce.

From Allen Cline, GM engineer:

quote Every all aluminum engine in the world requires special protection against internal corrosion. Whereas cast iron engines will rust and corrode and turn the coolant red with rust after the corrosion inhibitors in the coolant fail the engine will suffer little damage. Aluminum, on the other hand, exhibits a phenomena called hot transport deposition corrosion in which "bits" of aluminum at a high heat spot will break away from the surface and go into suspension in the coolant and will be deposited in the coolest part of the system. In other words, the material around the exhaust ports ends up in the radiator. The microscopic pits in the parent metal cause stress risers and the part then cracks. Ever wonder why so many NASCAR racers retire from a race with a "cracked head"..???...no corrosion inhibitors in the coolant they run (water - by the rules). So, engines with aluminum heads and all alluminum engines require a constant supply of corrosion inhibitors to negate this process and the all aluminum engines deplete the corrosion inhibitors in the coolant very quickly, much quicker than cast iron engines. In addition, since the coolant doesn't turn red with rust as in a cast iron engine, you get very little warning of the failing coolant....the coolant looks fine ( and will still offer anti-boil and anti-freeze protection as usual ) and checks fine on a hydrometer yet the aluminum heads are corroding and failing if the coolant is left in too long. One other thing to consider, the steel core of the gaskets ( ESPECIALLY THE HEAD GASKET ) can start to corrode and rot out from the coolant jacket areas outward toward the fire ring at the combustion chamber. If the core of the gaskets rots and fails then the gasket will collapse and fail. Now you understand why you hear so much about older Northstars loosing the head gaskets...????... Total lack of cooling system maintainence by the owner. I personally think the single biggest reason for long term engine problems on a Northstar is the lack of cooling system maintainence. There were two types of coolant in the Northstar. 93/94/95 engines got the conventional green coolant. This uses a silicated corrosion inhibitor that is VERY effective yet depletes in about 2-3 years and/or 30K miles. It needs to be drained and replaced. Period. The later engines from 96 on had the factory fill of DExCool coolant , the orange stuff, that Texaco developed with GM and markets under the DexCool name. This coolant uses an organic acid based corrosion inhibitor that never really depletes. It can easily go 100K or 5-10 years without a problem in an all aluminum engine. Both types of coolant are fundamentally the same.....ethylene-glycol based.....just the corrosion inhibitors are different. The coolant replenishment process is a lot , lot easier than people try to make it. Just drain what you can and refill with premixed 50/50 coolant/distilled water. Don't flush, run plain water thru the engine, run any caustic "cleaners" or do anything hard.....just drain and put fresh coolant in. The old coolant left will not cause a problem as it is not "dirty" or worn out or anything....it just needs a fresh charge of corrosion inhibitors from the new coolant added. There is no reason to switch an older 93/94/95 engine over to DexCool as the silicates deposited inside the engine from the green coolant will plate off and contaminate the DexCool and render the long life feature null. It'll need replacement every 2-3 years also. Just stick to the green stuff if the engine was started out on it. The coolant pellets are a completely different deal. They are a cooling system sealer (think BarsLeak ) to protect against any internal coolant intrusion into the engines oil which can be very detrimental. Just about all engines from all manufacturers get a small dose of a "coolant supplement" to guard against any type of tiny seepage or coolant intrusion due to a gasket surface imperfection, a scratch or mar in the gasket itself and to allow time for the gaskets to "seat" with time, temperature and thermocycling. Personally, every liquid cooled engine I own has "coolant supplemetn" in the cooling system as trying to make a perfectly leak free cooling system is very difficult. The GM "pellets" or dog turds as we call them are made by the same company that owns the BarsLeak name brand. The material is just ground up ginger root and walnut shells.....totally natural. The BarsLeak stuff is the same stuff just packaged in a dark soluable oil to aid in installation. If you find the powdered BarsLeak "gold" it is the exact same stuff. Use it. It will cause absolutely no harm....about the only detriment is the colant looks "dirty" but that is a good thing in this case. You should see BarsLeak's OEM customer list..!!! Just about everyone uses them from the factory. Don't use the BarsLeak "liquid aluminum" formerly called "solder seal". Not as effective and can clog stuff. You need new turds every time you replace the coolant as the old stuff is in suspension in the coolant you drained and it needs replenishing ,too. In addition, since the stuff is just microscopic fibers circulating in the coolant ( that start to swell when air gets to them in a leak site ) they get chopped up over time by the water pump vanes and loose their capability to seal. so they need to be replenished over time even if the coolant wasn't drained. The Northstar engine is no different in these respects than any other all aluminum engine in the world. Just that there are way more of them on the road than any other all aluminum engine so there are way more of them to eventually fail when the coolant wasn't maintained. BMW, Merc, Porsche have all had the same corrsion problems and all require frequent coolant replacement. You just don't hear about them because they are not as common, they are not being used by hotrodders, the owners tend to be maintainence freaks more than Caddy owners and they are too proud to admit their expensive baby wasn't taken care of. The Northstar owners ( and American drivers in general) got too used to casst iron boat anchors that required little or no cooling system maintainence to survive....just my two cents...... Just change your coolant occasionally and you'll be fine. I do my LT1 and LS1 once a year when I put them away in the fall....just a quick drain and refill with fresh stuff while I'm changing the oil. I think it adds about 10 minutes to the whole process. The DexCool won't hurt anything...it is actually beneficial even without the long life feature as it has no silicates which are abrasive to the water pump seal and can cause it to fail so your water pump seal has a better chance of long life with DesCool.....but just change it occasionally. The silicates in the block and heads will slowly plate off and contaminate the DexCool for several years or longer....practically speaking they never go away totally so you'll still need to change the DexCool occasionally.

From Will's post....

<start>
The coolant replenishment process is a lot , lot easier than
people try to make it. Just drain what you can and refill with premixed
50/50 coolant/distilled water. Don't flush, run plain water thru the
engine, run any caustic "cleaners" or do anything hard.....just drain and
put fresh coolant in. The old coolant left will not cause a problem as it
is not "dirty" or worn out or anything....it just needs a fresh charge of
corrosion inhibitors from the new coolant added.
<end>

That is contradictory to the IMcool.com article which is a report on a GM presentation at the 2001 MACS convention. GM/Texaco said weak additives and contamination are a large portion of the sludging problem.

That article also discusses flush/fill.

On the other hand he says don't use caustic flushes and other chemicals.... This is a good rule for all cooling systems with any aluminum parts at all. Things you could do to brass and cast iron do not fly with Al.

On BarsLeaks Gold.... Excelent stuff. Should be in any system, but it is a must have in Bi Metal motors. (Al heads on Iron Blocks) Those are well known for developing weepers along head gaskets. I tried it on my Caravan when it's 2.6 was weeping along the head gasket last year. Worked far better than expected. Bought me a couple months until I could rip the head off it and install a new gasket. (Yes, it's in both the van and my Fiero.)

As I've said before. I don't think DexCool is bad. I'm just not sure it's worth the BS to try and clean the system for conversion. The engine is next to imposible to clean short of a total tear down.