GM recomends dexcool in the cooling system, But Ive heard that it is bad to cause intake seals to leak. Any truth to this? My car has it now, but thinking of changing to something else at next flush.

 

All coolant will eat your engine over time. People that have problems with Dex are the same ones that don't check the coolant level.

 

Well I do know this, being a used car dealer I have had some issues with Dex-Cool eating away gaskets. Because of this I will never buy another 3.4L V6. I think the problem has to do more with the poor quality of the gaskets than it does of the actual Dex-Cool itself eating away the material. Nevertheless, I will not put Dex-Cool in my cars just in case it is the problem. I'd stay with with what has been working for years...regular ole antifreeze.

 

my dad owns a fleet of semis and me and him usualy do the maintenance on them and over the years we both came to a conclusion that the absolute best coolant is made by caterpillar its the cat absolute red, its expensive its 25 bucks for a straight gallon, but that stuff is great, a couple of years back he bought a used truck with 400k miles on it at the same time my dads own truck had 450k on it and the used truck had the green stuff in it and my dad had the cat red in since it was new his well since then the truck with the green stuff rusted out 3 bottom radiator hoses(they are metal) and my dad has 1.3million on his truck and still no problem at all he just changes it every 600k so all my cars have the cat red, import or domestic from the nissan to pontiac dont matter that stuff is the best by far and that last time the used truck rusted the bottom hose we changed it to the cat red and no probelms for about 200k now

 

of course it is bad "to cause the intake seals to leak".
but i'm sure you meant that dexcool is bad because it has been said to cause intake seals to leak. you need to research the issue and carefully consider your sources of information before you believe it to be true.
dexcool has had problems, and a smart unbiased person would look into the root cause of the problem instead of concluding that dexcool is simply bad even though 1 million+ cars have been on the road since 199x whenever with zero problems.

the one major cause of intake seal failure was the type of intake gasket material which reacted with the additives in dexcool. The problem was gasket material which was gm's fault and the fix was to change that gasket material, I think it might have been on one of the v-6 engine models. This info might be found at bobistheoilguy forums in the coolant section. But people on the internet being as smart as they are simply conclude a failure happened = dexcool bad. I'll bet if you actually due the statistics on traditional green antifreeze in a relevant apples to apples comparison that the same or more failures have happened on that stuff but of course nobody concludes that the problem there is the green antifreeze like they do with dexcool. Or maybe with all the marketing on 5yr/100k mile coolant life they somehow think that if there's a cooling system problem it's the coolant's fault not living up to the hype.

another problem with dexcool had also been improper initial fill of the systems, and also systems that leaked (not as a result of the type of coolant) and ran with airspace in the system when the block was iron, or there was ferrous metal in the system. Rust would form and cause problems- the cause here was not having the system properly filled and maintained.
if you search the web and at a website called imcool, they have a decent amount reliable tech info on the subject.

the key with all cooling systems and it applies to any antifreeze/coolant type, you need to have no air in the system, no leaks, the system able to hold the correct amount of pressure (~18psi) and the materials in contact with the coolant can't react to the additives in the antifreeze (hardly anything reacts to ethylene glycol, except people and animals). After you meet those simple requirements then the additives in all coolants eventually wear out and need to be replenished to prevent corrosion, so you change the coolant every 3 years for green stuff, 5 years for dexcool and other oat's.

 

I had dexacool in my car for the past two yrs and i hated it. My car ran really hot and everytime i flushed the car and refilled there were small chunks floating in the radiator. So i finally decided to switch over to the green coolant and my car runs way cooler and doesnt overheat anymore. Also when i pulled the knock sensor from the passenger side of the motor out and the drain plug on the driver side i had to ram a screw driver through all the gunk caused by the dexacool. Im glad i changed over.

 

https://ls1tech.com/forums/showthrea...=681507&page=4


http://www.imcool.com


http://www.gates.com/downloads/downl...older=brochure

 

The motor you are referring to is the 3.4 liter that GM put in a shitload of cars. Alero's, grand am's, bonnevilles, Achieva's, Impala's, grand prix, etc..

And I also stated that this problem could be because of bad gasket materials. I was telling real life problems I have had with the subject and not hearsay.

 

Wow... I've only ever run Dexcool and purified water, 50/50... Has always come out clean when flushed.

 

Same here.

I have been using DexCool for about 5 years in both my last car and current car. And I never had any issues.

 

With regular maintenance, dexcool is fine.

 

The best combo you can put in there is:

Half jug Dexcool
1 bottle water wetter
Distilled water for the remaining coolant

Dexcool with lubricate things and help keep the temps down. Use some.

 

I think you (or a previous owner/mechanic/tech) mixed the types of dexcool. If I remember correctly, if you mix two different types of dex it will cause those chunks to appear.

 

When I swapped my last car to DexCool the first time. I left in a tiny bit of residue from the regular ethaline glycol. It foamed a bit then started to have a whitish/beige paste form at the top of the reservoir. When I drained it, nothing chunky came out though. And that mixture was in my engine for over 2 years.

 

I think it's fine as long as you don't let it go acidic thats what causes problems, make sure its neutral with a voltometer

 

If you are referring to using dexcool in your LS1 then there is no way it will cause the intake gaskets to leak. No coolant whatsoever touches the intake manifold in these cars.

 

You are right. I think every one means head gaskets.