It might not be so bad on a LS1 with the gaskets, but a lot of the GM vehicles with a 3.4L V-6 family or 4.3L V-6 has a serious problem with dexcool eating away at the intake gasket material. You dont think it pisses GM off if they have to pay for a $1000 job under the 36K mile warrenty. Ford used it for one year and had multiple problems. They switched back immediately. But this is my hands on experience talking here. So dont take my word for it.

 

Again, this is probably only due to the fact that people falsely beleive that Dex can be left in the motor for so many years/miles. Had they followed the same change interval as the old green stuff, I doubt any of this would be the case.

Again, I'll be the first to admit that GM screwed up by telling their customers to leave dexcool in the motor for 5 years/150k miles, but I doubt the dexcool itself will do any harm if you change it the way you would with the green stuff.

PS. I've bought/worked on older cars that have always seen green stuff, and their owners were lacking in proper maintanence skills. Plenty of leaking heater cores, water pumps, and intake gaskets were the result. Green stuff can be very harmful as well if you don't follow proper maintanence. Let me tell you, if the green stuff has been in there for 5+ years and 60k miles that cooling system isn't looking pretty.

 

The intake gasket on my 3.8L Bonneville started leaking coolant right at 70k miles. But, I'm sure that has a lot to do with the fact that the original owner left the stock coolant in the car from 1996 until 2002 when I bought it. Even then, the gasket was good till 70k. Had the car received proper maintanence I'm sure the gasket would have lasted longer.

And I've had cars with green coolant get an intake gasket/waterpump leak at/before 70k miles as well.

 

The cooling system and motor are designed for Dex-cool.

Dexcool was developed specifically with aluminum engines and extended coolant change intervals in mind, its not just some stuff GM came up with to eat through gaskets quicker

In a clean engine, with the proper mix of DISTILLED water and coolant, Dexcool shouldn't cause any issues. Its no worse of a waterpump lubricant than the conventional green antifreeze, and it doesn't corrode anything aly worse either. In fact, its much less corrosive than the green in all aluminum engines, hence the reason it was designed in the first place.

GM isn't the only one to use Dexcool, either. Plenty of other manufacturers (VW uses a coolant similar to Dexcool) use it as well.

I'll be sticking with Dexcool for my car, thats what came with it and thats whats reccommended.

 

actually, it's pretty much proven dexcool's "extended change interval" is grossly overrated, and aluminum engines have been around for 50 years. those blocks are still around today and they never touched dexcool. so:
1.) dexcool's change interval is overrated
2.) green coolant won't hurt your block

so what's the point of dexcool again? there is no point. GM just pushes it because they get a kickback for using it, just like they get a kickback from mobil for recommending mobil 1 in corvettes. if anything, it's a baby-conspiracy.

i don't understand why people are concerned about either coolant corroding their block. your engine block will still be intact long after you're dead and buried. the only thing you should be worried about are fragile, rubber seals and gaskets, and it's proven dexcool chews them up more than green coolant.

again, GM designed the f-body to work with a 10-bolt rear end. does that make the 10-bolt a good choice because the f-body was designed to run it? just because GM uses is doesn't mean it's a good idea. nearly all decisions are made in the name of profit. GM is using dexcool because they make more money by using dexcool. neither coolant is going to outright harm your car or perform any better or any worse. dexcool just has a worse track record with water pumps. i learned that the hard way. i never had a problem with dexcool until a few months ago when it ate my water pump after only 30k miles and i began talking to mechanics about it

 

 

whoever said most cars blow there water pumps at 30k miles....is kinda off...just a tad...

 

Yeah im at almost 100K on mine and that includes removing it for an engine swap too. My water pump gaskets were fine too when i took the pump off for the engine swap too. My car has used both dex and green.

 

i hate all of you bastards that run any coolent at the track.

 

 

Until I see some proof in this thread, and not just a bunch of hearsay coming from both sides, nothing has been "pretty much proven."

Use whatever you want. It is your money. However, there has been absolutely no scientific method used in this thread, just more anectodal "my friend said this, or my mechanic said that."

 

ask just about any mechanic out there along with the majority of people on this board. even the guys that are devout with dexcool will for the most part readily admit it's not going to last 5 years/150,000 miles and you should get it out before then. if i was using dexcool, i would have it changed every other year just like the green coolant. it turns into a skunky smelling vinegar if it goes too long, and if it's exposed to air, it turns almost into jello and gets yellow/orange crust all over the place.

when i changed my coolant the first time (for more dexcool), it smelled like i hit pepe le pu with my car. it smelled like straight up skunk. it was awful. i checked the undercarriage of my car. the water pump was bone dry. i put more dexcool in it. like clockwork, a few miles later, i started smelling coolant. i brought it over to my buddy's brother's shop to get a cutout welded into my I-pipe, and i checked out the water pump. the oil pan was covered in a big stream of coolant. i bought a new water pump, flushed the system 4-count'em-4 times, switched to green coolant and haven't looked back.

what kind of proof do you want? do you want GM to actually come out and say "dexcool isn't going to last as long as we advertise"? because they'll NEVER do that unless they get dozens of lawsuits. you know how GM works. just ask mechanics. they'll tell you what dexcool is good for - taking up shelf space.

 

Agreed.

I use Dexcool, and will continue to use dexcool, but I would never leave it in for 5/150 without adding some fresh, that is just asking for trouble regardless of what coolant you use.

Choco, obviously you had a situation where the water pump started leaking at a very early age, but for the most part LS1s don't see issues with low mileage (30,000ish) coolant leaks like that.

FWIW, when I bought my '98 car in late 2004, the original owner had never changed the stock coolant. Granted, the car only had 11,000 miles on it, but still 6 years with the 100% stock coolant is too long. It had turned to a milky brownish type color, but there wasn't really any sludge or foul odor. I had the system fully flushed by the dealer in the spring of '05 to start it off right; then in the spring of '06 I drained/refilled the radiator with fresh dex/distilled water mix, and now in '07 there are still no leaks, and the fluid is clean and pink. I'll be doing another drain/refill in about 1 more month.

I generally drain/refill the radiator every spring since the car only sees about 1,000 miles of use anually. A full system flush seems unnecessary for such limited use, since I'm repalcing a significant amount of fluid every spring anyway. I followed the same pratice on my limited use '00 WS6 for over 4 years and the coolant in that car was also always clean and translucent pink without any cooling system issues ever. But my situation with these two cars is not the norm, since they were/are rarely driven, and as such this routine will not be ideal for regularly driven cars.

Now, for my daily drivers that see regular/normal usage & mileage, I get those systems fully flushed once every 2 years, 3 at most. Seems to be working well.

 

My car had Dexcool in it for 5 years, and I had no problems with it. Like I said, this is all just internet hearsay to me, as I have mechanics I have asked, and I have worked with the stuff myself. My own experience is contradictory to yours, so whatever.

 

i'm afraid i'm scarred for life
it's not just hearsay. it's a stereotype for a reason. running dexcool for its advertised length is dangerous. it eats water pump seals and gaskets. if you're gonna run it, change it out early.

 

This has escaladed into a huge debate, with neither side having any legit facts or proof that Dexcool is good or bad.

Choco had a bad experience with his waterpump, it was probably defective from the factory, simple as that. Otherwise there would be many more people with the same problem.

Leaving any coolant in the engine for 5 years/150K is pointless and dumb. Thats a given. In simulated tests, the coolant probably lasts that long. In the real world it doesn't. Its not that complicated.

Heres my advice:

1. Stick with Dexcool, which came with the car from the factory.

2. Change it every 50K-75K miles, or every year or two. You shouldn't have any problem. There is no decisive answer here, saying "green is good and dex is Bad" is a baseless statement and doesn't prove anything.

 

The flaw in the logic is that GM engines that run dexcool have intake gasket failures, therefore the dexcool is the cause. Coincidence does not prove causality.

The cause can be any number of things, poor quailty gaskets being highly suspect. Ask any older GM tech if he remembers the HT4100. GM intake gasket failures caused engine failure long before dexcool.

It's well known that the 3800 intake gasket failure is due to EGR. Dexcool is only one of a number of suspects when it comes to this chronic problem with GM engines.

 

This thread reminds me to change the the dexcool in the gf's 2001 cavalier. Don't think the previous owner ever changed it. I've added a little awhile ago, but it still looks nice and orange and doesn't smell anything foul.

 

Its not flawed logic at all. Its experience.....After the change to Green coolant from Dexcool the problems mysteriously go away. In my experience for example with my '98 blazer I went through one intake gasket, one waterpump and one freezeplug at different times to 90,000 miles of dexcool use. I changed to Green and did not have another cooling issue up to sale of the vehicle at 170,000 miles. This was on MY personal vehicle, customers results of which I have probably 100 have been VERY similar. I suppose someone could test green vs dexcool acidicity on the same vehicles over similar intervals but Im convinced.....and so are most in the industry.

 

But that is exactly the point. These are only YOUR experiences. My experiences have been quite the contrary with Dexcool. So why should I bought to change to the green **** just because a bunch of people over the internet are claiming how bad dexcool is, when I have had absolutely no problems with it? Hell, I did run the **** for 5 years, and the engine was fine. No weird smells, no weird gunk. Winter gets to be in the teens around here, and summer is in the 90s. No problems with the stuff. And I am not gentle to my car.