anyone use this in there engine, im rebuilding my 350 and was thinking about it? pros/cons

 

Good stuff... not silicone based...it is fully synthetic, which is why it can be used for so long.

 

Hah..I just did a search on Dex cool about 2 hrs ago. I hear mixed reviews. A buddy of mine says it eats thru aluminum over time. Maybe its GMs way of getting back their cars so they can be serviced. Another way for them to make some cash. Maybe thats why my radiator just went. I'm sticking with the green stuff from now on.

 

I've used it and have noticed some of the 'so-called' problems that a-lot of the articles state. But really the only things I can say is that the orange film was present and I had a small coolant hose or two fail (but this vechicle had over 200K on it so I cant point a finger at the dex-cool).

IMHO it has more to do with the water you put into your car when you add this to your system (and the mineral/contaminents inherent in the water alone). PH, electrolysis and some other things do add to the equation.

Since I live in So. Cal. I no longer use coolant, just demineralized water and RedLine's 'Water Wetter', in the cars and when winter comes around I do throw enough dex-cool into the trucks system so it will not freeze......and when summer comes around it goes away.

 

I agree with Chacane, I think most of the problems mentioned have to do with hard water rather than dex cool. I've used it w/ no problems, but I also only use distilled water in the radiator as well.

 

i just stuck with prestone antifreeze. i was going to try dexcool but i just stayed with the good old green stuff..

 

It could be a total fluke, but I doubt it.

I've had 2 GM V6 engines that came stock with that crap in them, and both of them had the intake gaskets fail. One was a '95 Monte Carlo with a 3.1L V6 with only ~30K miles, and the other was a '96 Lumina Minivan with a 3.4L V6 with ~110K miles.

Both of those engines have Sequential Fuel Injection (SFI). The SFI uses a 2 part intake manifold similar to TPI. There's an upper plenum and a lower plenum, both aluminum. Both engines leaked coolant into the crankcase through the water jackets and into the lifter valley, then falling into the oil pan.

When I took both of them apart to replace the gaskets I noticed on both engines, around every water jacket on both plenums, that the aluminum was pitted all the way around. And I mean pitted enough to were I almost bought new intake manifolds. Can you say "lots o' money"? But instead I just caked the crap around them with black RTV.

I've had numerous SBC engines with aluminum intakes and never had a problem like that. Of course that was when the green stuff was all that was used.

I'm a believer that the orange stuff is BAD!!!!!! I'll stick to the green stuff, thanks.

Just my 2¢,

AJ

 

I work at a GM dealer and I hate the stuff. after time it starts to build up a mud looking substance around the cap on the radiator.. As for the intakes leaking on the 3.1 and 3.4 its something that happens all the time. we put so many intake gaskets on at work its not funny. its just something with that engine design. I would stick with the green stuff but then again thats just me.

 

The green stuff will eat through almunium the dexcool wont also dont mix the green stuff with the dex cool stuff it will to to a jello like sludge.

 

I'll agree with you that it's not at all funny, nor fun.

"Full floating intake manifold" is how they describe it. The only thing I want full floating on my car is the air inside the tires.

As soon as I read the specs on the torque that holds on the upper plenum I was like "damn"!!!!! 115 in/lbs. I can apply that if I sneeze hard enough. What a joke.

AJ

 

Ive been running dexcool in my camaro for about 4 years its a 3.1 havent had any leaks.

 

I didn't say the leaks were from the coolant. I said that the water jackets on the intake manifold were pitted from the coolant.

The leaking is caused from the design of the intake manifold(s) like meridius and I were talking about. That has nothing to do with the coolant they used, it's just a crappy design.

First; Learn how to spell aluminum.

Second; Let's see. I've pulled probably 6 intakes in my life now, and EVERY ONE that had the green stuff (which would be a total of four for those who can't subtract) was fine. The 2 mentioned above BOTH had pitting and BOTH used that orange crap.

You don't really expect me to believe you, do you?

AJ

 

I was just sayin what i was told now i know i was wrong ive just herd some mechanics say what i had said about the green stuff thats all.

 

526 miles on the motor/dex-crap ...

 

I have dex-cool in my 00 TA. After 30K miles there's "mud" on the coolant stick. I'm not thrilled about that. No problems with leaks yet but I guess it's just a matter of time.
The only thing I use in my other cars is Prestone and distilled water. Prestone has no silicates.

 

One thing about Dexcool is that it cannot be put in an engine that had conventional antifreeze in it before, unless the system is thoroughly cleaned out of any traces of the old stuff. This is virtually impossible. All these cars originally came with conventonal coolant, so unless you've built a new engine from scratch with a new rad and a block that's been chemically cleaned out, forget about it. Frankly, the purpose of the orange stuff is that it lasts twice as long as the green stuff. But it also costs twice as much. With the amount of times we work on our cars and drain the coolant, it's not worth the initial expense and other hassles we've heard about.

 

The pic above is the Dex-shyt creeping out of my seals and it also toasted my heater valve. My block is GM new from the dealership and everything else was cleaned by me or new except the radiator which was 6mo old prior to my motor being redone and the heater core which is still original.

Under a severe mental lapse.. I thought the dex-stuff would be worth a try since the motor part was basically like a new car. Apparently the above is what I get for thinking.....

 

dex-crap :nono: sucks the big one............

 

I've tried dex cool stuff too and I've seen crap floating in my radiator when I pull the cap. I'm not very pleased with it..... used green untill like 93k miles switched over to dex cool here I am at only 100k miles and I blew a radiator leak the other day.... so I think I'm going back to the old green stuff with my new griffin as soon I get the cash to buy it that is... hehe

Stupid motor builds they always drain you of your money.... I am going full float pistons though.... so see there is something else that you might like to be full float on your car AJ_92RS.

 

Yup. You got me there.

AJ

 

Maybe I'm just lucky... My wife's 96 Gran Prix has the 3.1 engine and it came with Dex Cool. It has 120k miles, the only thing I've done is an alternator and battery, not including normal oil changes, air filters, etc. Hell, it's still running with the factory spark plugs. It gets 25-28 mpg combined city / highway, it doesn't lose a drop of coolant or oil between oil changes, and it still has good power for a small FWD V6.

Hell, on the highway the thing recently knocked down 32mpg averaging 75 mph on a trip.

Yes, I've seen some "mud" sort of stuff around the radiator cap, and coolant tank, but after flushing and now using distilled water, it looks fine to me. It never runs hot, AC still blows cold on original charge etc.

As for GM using it to make money... wrong answer. Trust me, I worked for GM for a good while..if they spend the extra cash for R&D and then upgrade a product, there's a good reason. Why would they want to have to do more warranty repairs?

Fact of life, alum will get corroded alot easier than iron. Another fact is that alot of well water, and treated city water is high in certain chemicals that will corrode alum alot faster than normal.

Maybe I'm just lucky.

Oh well

 

Nobody ever said that they'd all do that. It's just likely to happen.

Like I said, it's happened twice to me, so hopefully you can go through at aleast two that won't do it to you. I took the bad ones for ya'. "Take one for the team!!!!!"

AJ

 

I have not had any problems with going form the green stuff to dex cool i did it on my moms car and my car and havent had 1 problem.

 

okay i think i might be the onlyone but i thought u can only get straight up dex-cool from a GM dealer. the antifreeze u see in like pepboys is not dex-cool but it is approved by dex-cool. it cools alittle better then the green stuff but it isnt dex-cool. if u look on the prestone (i think it is) bottles (gray and come with a cool handle) it will say in the upper right of the bottle "DEX-COOL APPROVED"

if this stuff is as bad as the dex-cool i think maybe next week or something ill flush and fill my radiator back up with the green stuff and throw a bottle of redline in there also.

 

I talked to my pontiac mechanic friend about just that. He said that the prestone and havoline dex-cool "approved" is actually better than GM's dex-cool. He said the mud comes from the actual dex-cool evaporating. Prestone and Havoline's will not evaporate just like the glycol (green) does not.
As for leaks such as the earlier picture.....he thinks it was either over/under torqued or there was pitting that didn't get properly sealed.
Too, water pumps failing, the seals were designed for dex-cool on the new cars. You must remove all dex-cool from the system to not run it. He's not aware of any type of flush that can do that. However he did say that draining the rad, heater core, and pulling the freeze plugs then flushing should remove enough to not cause problems.
As for switching from glycol to dex-cool approved there shouldn't be a problem with a good flush.

 

I have spoken to Texaco about Dexcool(they formulated it for GM) and the in's and out's of using it in older vehicles. The story from thier engineering dept is this. You cannot have more than a 10% residual amount of conventional coolant in the system. Thier recommendation is this. Flush the system and fill with Dexcool/distilled water. Run vehicle approx. 2 wks, then drain, flush, and refill again. Dexcool when either contaminated or subject to overheating will generate a particle like residue and in some cases will plug up the cooling system. Properly maintained it will provide a longer service interval, but Texaco cautions that on older cars to maintain the same service interval as conventional(2yrs) so maybe there is no savings there. I have spoken to friends at 2 different GM dealerships and it is almost a 50/50 split as to whether it is any benefit. One advantage is it is silicate free, supposedly it makes the seals hold up better. Either Texaco Havoline or GM Goodwrench are original formula. Other brands are supposedly licenced. Who knows.

 

Silicate free is why I use prestone's green stuff. Every other af that i've looked at has silicates.

 

Although I use the green, and have no plans to change over to dexcool, I do find it hard to believe that GM would do research on something and then approve it, with it being worse.

 

In the truck world we call it Death Cool.

 

2 years later lol. I went back to the green stuff and my car runs a little cooler then it did with dexcool. I do have the Texaco brand i still have about 6 gallons of it Stocked up at Kmart when they were going out of business. Some day it will be used.

 

I ran the Prestone Dex-Cool Approved coolant in my car for the last few years. I had no problems, but I recently found a small amount of the "orange mud" in the bottom of my overflow bottle.

This inspired me to flush the system and go back to the green. I also have a '96 Cadillac that uses Dex-Cool and the recovery tank is coated with a brown film.

There also seems to be quite a bit of "mythology" going around about Dex-Cool. "Don't ever do this or else" types of things. From what I've read many of these claims aren't true or are based on speculation at best.

From my research, it appears that Dex-Cool has issues with exposure to air. This MAY be the cause of the sludging. I've also read that Dex-Cool may not last the advertised 5yrs/150,000 miles and that it should be changed every 2yrs/30,000 miles just like the green coolant.

Dex-Cool does offer better protection for aluminum, but IMHO it's not worth it if it ends up gumming up your cooling system. Some people have had good luck with Dex-Cool, while others have had their cooling systems fouled up by the stuff.

With regards to pitted aluminum, that can happen with any coolant. When you have dis-similar metals connected to each other (ie: aluminum intake bolted to iron heads), with water passing thru the parts, you get electrolysis. This process attacks the aluminum. I had to replace my intake manifold because of this and it is not uncommon.

As far as GM knowing their stuff and they wouldn't use Dex-Cool if it was bad – keep in mind that what works short-term in the lab doesn't always work under real world use. GM probably thought Dex-Cool would be an improvement, but ask any GM dealership about it (and if they are honest about it) they will tell you about the problems they've seen in some cars.

 

I wouldn't put the stuff in a Ford. Seen enough to know better. Regular green Prestone can't be beat.

 

Doesnt have a problem with air. Otherwise the overflow bottle would be having the same problems.

"One of the components of dexcool is a plastic softener. Also the sludge buildup is actually because the coolant got low, its the iron heads rusting, the sludge is what results."

 

The overflow bottle is exactly where I found about a tablespoon full of the sludge appearing in my car. This makes me think the air hypothesis may have some value. '96 and newer GM cars (which Dex-Cool was designed for) use totally sealed cooling systems.

I keep my car well maintained and never ran the coolant low, so I doubt the sludge I found was due to rust in the system from a low coolant level.

As far as the plastic softener, do you have any more info. on this? This seems really strange to me seeing as how most newer cars have plastic engine components. Any info. that goes into this further would be great.

 

DEX COOL = Sludge

 

Wow, this post has some staying power. I suspect the Dexcool problem is just one other reason GM is in the dire straits it has found itself. People get fed up.

 

I fought with my jimmy for a while trying to get the dexa-cool sludge out of my cooling system after many failed attempts with the prestone raidiator cleaner crap I made my own cleaner and it worked better than expected...

Don't use DEXA-COOL

 

I work as a tech at our local GM dealer, there was a class action lawsuit against GM, im not too sure if it is going on still, but Dex-cool was found to be linked to the failure of both the intake gaskets on the GM v6 which ALREADY had a horrible problem with blowing gaskets, as well as a factor in the failure of the north star head gaskets. GM Dex-cool was found to be EATING the gasket materials. the new intake gaskets are all revised. the bottom line? if your engine was not DESIGNED to have dex-cool in it then dont RUN dexcool in it. dexcool is for 1996 and later GM engines with the proper gaskets, rememebr dexcool is not a silicate based Ethelyne Glycol like the green ****, which is what your gaskets were made to handle, besides, our enings are not aluminum, so what does it matter? also yes dex-cool DOES SLUDGE UP WHEN IT GETS OLD. IT MEANS TIME TO CHANGE THE S.H.I.T!

 

I am no expert or anything like that. But this is my thoughts.
I really don't hear anything good about Dex-Cool. I hear some people say they haven't had a problem yet. But then again they are probably the people that will buy a car and not do anything to it but put gas in it, until they are over 100,000 miles.
I keep seeing post about Dex-Cool turning to sludge, or eating up intake gaskets.
I have seen alot of pics of what it does do.
I cannot say why it turns to sludge, air in the system, rust whatever. I know it does.
I will give it this much, green will rust if left long enough. However green will not turn to sludge, or eat up gaskets. So why mess with something that can clog up the radiator, heater core, eat up the intake gasket whatnot, when I can put green coolant in, run it with air in the system, not touch it for 5 years, and it's still going to run fine. Yes I know air in the system can cause it to overheat, and 5 years will cause rust. Point being you could add water/coolant, and just drive it.

 

The dex cool turned to sludge in two years in my car. I am not sure if it had anything to do with the copper/brass three core radiator I had put in it. Chemical reaction?

 

no... dex-cools chemical composition is the issue, it slowly thickens and sludges over time

 

Cool, so I don't have to get a new radiator.

 

I thought Dex was good stuff. But you need to flush out all the old green anti-freeze really good. I was told the Dex and green kinda react with each other, causing the mud. No Dex for me, I'm going Amsoil anti-freeze.

 

not srue if any of yall know but there was a law suit against GM for repairs on some models of silverados due to intake gasket failure. I did alil searching and file against them as well but they wouldnt cover my yr model since it wasnt the v-6 model. Total bs imo but o well. i did the 30 dollar gasket myself 16 hrs of labor later. It been about 5 yrs since i did and no problems yet. Guess i did a good job

 

All I know if I ever get a new Camaro or other GM product, I am flushing out that Dex Cool crap out and putting in the green stuff. Don't think it will affect the mechanicals of the car as Dex Cool is some nasty SH*T.

 

forgot to mention i had the rusty color look all inside my radiator and also believe that stuff caused my quick connect to snap off inside my intake. Lucky it wasnt an expensive to have taken out

 

every vehicle i have had that had dex cool in it got drained,flushed ,and refilled with the good ol green stuff. dex cool is very sensitive to leaks. the leaks no matter how small it will begin to crystalize in that spot. it is also sensitive to being clean. there are some people that say that the newer systems have to have dexcool. (wrong). i have had old and very new vehicles and all have the green stuff and a bottle of water wetter. they work perfect. and with the green i can remove the cap in a bad instance and run it like that.

 

drained all my coolant and used the green stuff that is dexcool compatible, no problems