Dex-cool

Hey guys, I was wondering if anyone knew of problems using regular coolant instead of required dex-cool. I've noticed a nasty sludge in my coolant tank.


Thanks,
ch Ron ic

[Vtolds]

It should run fine on regular coolant, BUT and thats a BIG BUT. But you need to completely Drain and Flush the system first otherwise it can do some stuff, probably including sludging.

[freakout]

Someone had switched mine to regular coolant before I bought it. They failed to remove all the dexcool. I thought I had oil in my coolant due to LIM leak but that is the what the sludge looks like, it was collecting in the cap of the overflow tank. When the LIM was done switched back to dexcool. It has been flushed twice by me and once by a rad shop still have sludge showing up. The rad shop said good luck trying to get rid of it, no matter how good a flush and fill . IMO I wouldn't switch.

if you've got the 3400 then check your LIM gasket for leaks. But if you plan on switching, flush flush flush flush flush flush and one more flush.

[Cliff8928]

Dex-Cool isn't all that different from the regular green stuff, it's just a silicate free version. There's no documented harsh interaction from the mixing of the two that I know of, just it won't last 5/150. The most important thing with the Dex-Cool is to make sure that your coolant is full all the time, supposedly air in the system is a bad thing, and that's something that Texaco (the manufacturer of the OEM) says. (although I suppose it could be that way with the old stuff too). All the vehicles that I've done flushes on have Dex-Cool in them, ranging from cars, motorcycles, tractors, and even a skid-steer.

Have you ever mixed the two? I accidentally poured regular coolant in my girl's sunfire when she popped a rad hose loose. It instantly overheated. I wasn't thinking about the fact it was GM when I poured the regular stuff in. Anyway, I've also poured a little of each into a container to see what would happen and they turned into a gel like substance. Trust me, you don't want to do this in your motor or rad.

[justinusaf]

Dex Cool is a synthetic coolant. If you are going to change it try to change over to another synthetic coolant. Other coolants will break down where Dex Cool is made to last the lifetime of the vehicle. It actually has ingredients in it to extend the life of gaskets. When you switch to a non synthetic coolant you run the risk of gasket failures. Given that the Lower intake Manifold gasket leaks in most 3400's its not because of the coolant its because of poopty gaskets made by GM.

[Cliff8928]

Dex-Cool is still a Ethylene Glycol based coolant... All the regular green stuff eventually turns into a gel anyways.

here's the official data on dex-cool

http://www.havoline.com/products/na/...e_01_tech.html

Originally posted by justinusaf@Apr 12 2005, 12:44 PM
Other coolants will break down where Dex Cool is made to last the lifetime of the vehicle. It actually has ingredients in it to extend the life of gaskets. When you switch to a non synthetic coolant you run the risk of gasket failures.

Quoted post

um, you sure about that?

lifetime of the vehicle huh? is that why GM recomends to change it at 100k, and by that time, its a big goopity mess of brown sludge? you'll be lucky to get 100k miles.

gasket life extension? sorry, nope. where did you hear that one?

gasket failure? thats funny, ive always ran the green stuff. i got rid of dexcool as soon as i got the engine. gasket failure is from improper installation, manufacture defects, detonation, and age. not from switching.





btw, i have no problems with dexcool, but from my experiences and my group of friends, we prefer the green stuff.

[Cliff8928]

The current change interval for Dex-Cool is 5 years or 150,000 miles, whichever comes first. I've had it in vehicles for 5 years (probably 70,000 miles?) and it never got "goopty". It actually looked fine. However, they did have a bad batch of it when it first came out, but that only matters to early 96 models which should be on their third batch by now.

all i was saying is that either one is fine, but neither is better than the other IMO.


they both cool off the engine, and they both do the job they are supposed to do.

green generaly costs less
red generaly has a bad rap

but i see no benifit of one kind over the other, i have used both and both do just fine.

but keep this in mind.....


if you ever take your car into a shop, and they top off your cars fluids, 9 of 10 times they will "want" to use the green stuff. most tech's wont pay attention to what your sticker says, and will just shove the hose down into your fill tank/radiator and push the button that says coolant.

[Cliff8928]

Originally posted by germ@Apr 13 2005, 07:14 AM
if you ever take your car into a shop, and they top off your cars fluids, 9 of 10 times they will "want" to use the green stuff. most tech's wont pay attention to what your sticker says, and will just shove the hose down into your fill tank/radiator and push the button that says coolant.

Quoted post

Been there, done that. If a friend wasn't the estimator at the shop, probably would've complained and made 'em change it. That one's probably due for a change soon, red will go back in 'cause it lasts longer.

[alero440]

uhhh ohhh I get my oil changed here at the honda store I work for... I wonder if the tech are smart enough to use dex-cool and not the honda coolant... Hmmm I'll have to ask