Dex-Cool

revrnd · March 16, 2005

I'm on my 3rd truck that uses Dex-Cool. The first a '94 K1500, I put 100,000 miles on it w/ no problems. The second a 2000 K2500 that had just over 60,000 miles on it when I sold it. Also, my brother has put about a 100,000 miles on 2 of his trucks w/ Dex-Cool & no problems.

None of the trucks never had cooling problems. On a snowmobile website, someone asked why the OEMs don't use it. A few guys posted that mechanics say that it's evil on motors blah blah blah. Is there any common thread to the problems associated w/ Dex-Cool? How can some people have no issues & others have the coolant "gel". Yes, that was posted as a problem.

Sorry if this has been asked before.

zorrro · March 20, 2005

At 125,000 mi and 90,000 mi, I have had no engine problems with Dex-cool. The only thing I do not like is a crusty build-up around the inside of my radiator caps and the overflow tanks. A dealership said the solution was to replace the cap, keep the filler neck clean and replace the overflow tank (easier than cleaning). I have done nothing to remedy this. I will soon replace hoses on the suburban and it will get new Dex-cool and purified water.

builderpaul · March 20, 2005

I'm on my 3rd truck that uses Dex-Cool. The first a '94 K1500, I put 100,000 miles on it w/ no problems. The second a 2000 K2500 that had just over 60,000 miles on it when I sold it. Also, my brother has put about a 100,000 miles on 2 of his trucks w/ Dex-Cool & no problems.

None of the trucks never had cooling problems. On a snowmobile website, someone asked why the OEMs don't use it. A few guys posted that mechanics say that it's evil on motors blah blah blah. Is there any common thread to the problems associated w/ Dex-Cool? How can some people have no issues & others have the coolant "gel". Yes, that was posted as a problem.

Sorry if this has been asked before.

<{POST_SNAPBACK}>

Many, myself included, had coolent leaks from intake manifords and heater elbows. Altough probubly not related to dexcool they were often attributed to dexcool so it got a bad rep. I know dexcool doesn't like any contact with air and doesn't like any mixing with other coolent types.

likearock · September 8, 2006

i had to rebuilt my top end on a 454 due to dex-cool

diagnosed with head gasket leaks on both heads the truck had never overheated it very rarely even sees 180 degrees Tear it down yank the heads off and i almost S$%t my pants when i saw the water jackets in the heads and in the block the jackets behind 7 and 8 were easially 75% clogged and the pluggage decreased toward 1 and 2 about 10 to 15% clogged no wonder the heads warpped they could not dissapate any heat after 300 bucks at the local machine shop (hot tanked and machine work) there good as new She got the green stuff at the end of that project.

Like A Rock

revrnd · September 11, 2006

I'm wondering if these "Dex-Cool problems" are due to the crappy gasket materials GM used & the coolant problems would have occurred using ethylene glycol based based antiofreeze?

95Sierra2500 · September 11, 2006

The 'gelling' problem I have heard is attributed to having the car serviced and some retard mixes up the green stuff and pours that in w/the dex-cool. That said, whenever I need new coolant and do a flush, I usually just use the green stuff because it's ALOT cheaper.

duramaxHD · September 11, 2006

The 'gelling' problem I have heard is attributed to having the car serviced and some retard mixes up the green stuff and pours that in w/the dex-cool. That said, whenever I need new coolant and do a flush, I usually just use the green stuff because it's ALOT cheaper.

<{POST_SNAPBACK}>

exactly!!! I still dont buy all the Dex-Cool myths. I see nothing wrong with Dex-Cool. Its good stuff, lasts a long time, good boil over protection, and I have had no problems with it whatsoever. As you said, Id be willing to bet 99% of the Dex-Cool "problems" are from dummy's topping it off with green antifreeze.

jake111 · September 12, 2006

A few weeks ago I searched articles on coolant and learned about the traditional American green (mostly silicates) and that the Japanese makers didn't like that and wanted phosphate based corrosion inhibitors, and then about OAT (like Dex-Cool) and HOAT, etc. I was doing my Toyota at the time, so I decided I would pay the dealer whatever the outrageous price was, but I was going to get Toyota approved phosphate based red antifreeze. Wrong. Toyota reformulated a few years ago and now only sells "extended life" antifreeze. It's still red but the label listed things (I didn't write them down) that sounded an awful lot like . . . Dex-Cool (or at least it was an OAT-like). I didn't buy it since I could get the equivalent elsewhere at less than half the price.

So I went to Autozone. There it was . . .Prestone in the familiar yellow jug but now it was "Extended Life" and "New Forumla - All Makes All Models" "Mix with ANY color antifreeze". Does it get any better than that???

Oh, except the label lists exactly the same ingredients as what is in their gray Dex-Cool jug. (Might be in different concentrations, I don't know.) But the new stuff is dyed a gold-green instead of orange-pink (at least in my old jug of Prestone Dex-Cool).

I don't think I found any silicate based antifreeze on the shelf, but I might not have looked very hard. You should be able to find Zerex G05 (a HOAT), but that's really officially approved for Ford (and Chryler?).

I gave up and went with Prestone (yellow jug for Toyota; gray for GM). BTW, current thinking is that Dex-Cool (and now the new stuff, too?) is sensitive to air, so try to have a tight recovery system and don't let the reservoir run dry.

TEE · September 15, 2006

My 04 Sierra has 34K on it and as soon as the warraty is up..The Dexcool is GONE!

Heard tooooooo many horror stories and everyone that I've talked to that switched...were glad they did.

Mine looks like dirty pink lemonade and the dealer even said it needed replaced...SO I said," Why don't you reaplce it since it's under warranty"?...NOT!

C/K Man · September 17, 2006

I'm wondering if these "Dex-Cool problems" are due to the crappy gasket materials GM used & the coolant problems would have occurred using ethylene glycol based based antiofreeze?

<{POST_SNAPBACK}>

I think a lot of problems are incorrectly blamed on Dex-Cool. The GM 60 degree V-6's (2.8L, 3.1L, 3.4L) were having a lot of intake manifold gasket problems long before Dex-Cool came out in '95.

wht2500hd... · January 22, 2008

Never had any problems with any type of coolant.

2500 HD 6.0

Tow less than 7500 lbs.

This summer, after traveling over an hour from mountains (in 95 degree temperatures) I stopped for gas; before shutting off engine I raised the hood. I saw bubbles entering the surge tank Never have had any coolant loss and have never added coolant and never overheated or run hot (2003 and 25,000 miles).

On the surge tank the coolant enters at the top of the tank ? This can create bubbles; if it entered from the bottom there would be no bubbles.

Do I have a leaking head gasket ?

doverarjim · January 23, 2008

The only problem that I had with the cooling system was that I needed to add Dex-Cool about every 3 months not a lot but still needed about 1 gallon every year. When getting the oil changed took oil samples and sent them off to be tested never had any problmes at all. I changed out the Dex-Cool at about 100,000 miles and went on my way fat dumb and happy, about 120,000 started needing to add coolant every 30 days, then it soon became every week would need about a gallon. Found problem was in raditor, replaced it and the shop added the green stuff, that was at 135.000 miles. It seems to take about 10 minutes longer for the truck to warm up and takes more than 15 minutes for the windows to defrost, these times are with green in the truck instead of dex-cool. I am still adding coolant about once a month now with the green stuff, but its not going into oil? For my money next time I need to change something I will go back to dex-cool after a good system flushing.

Zembonez · January 23, 2008

It's funny how many of us will base our opinions on "I've heard horror stories about ------"

I've had DexCool in all of my GM vehicles that came with it for as long as I owned them with no problems... Funny thing is this... this is exactly the same results I have had with other vehicles that used traditional green antifreeze...

My vehicles with K&N filters produced exactly the same results as my paper filtered ones.

My Mobile1 oil changed vehicles have performed exactly as have my dino changed ones.

A lot of us seem to buy into "old wives tales" when it comes to anti freeze, Oil changes, air filters, tires, shocks, etc. I laugh when I read posts from those who choose to claim they can tell any real difference in most of the stuff that we do to our vehicles.

It would appear that opinions are really bullsh!t. Yours, mine, everybody's... But I sure hope we continue to do this stuff. If not what the hell would we argue about?

wht2500hd... · January 28, 2008

I need to ask this question one more time:

03 2500 HD 6.0

Tow less than 7500 lbs.

This summer, after traveling over an hour from mountains (in 95 degree temperatures) I stopped for gas; before shutting off engine I raised the hood. I saw bubbles entering the surge tank Never have had any coolant loss and have never added coolant and never overheated or run hot (2003 and 25,000 miles).

On the surge tank the coolant enters at the top of the tank ? This can create bubbles; if it entered from the bottom there would be no bubbles.

Do I have a leaking head gasket ?

Zembonez · January 28, 2008

Sort of a thread hijack there but it's an old one so here goes.

It's quite common for coolant to bubble over into the recovery tank when the engine is hot. In fact that is exactly what the tank is there for. When you stop and idle a hot engine, or shut the engine off, the coolant superheats for a few minutes since it isn't being circulated through the system. Because of this it expands and forces its way past the raditaor cap and into the overflow tank. Once it cools, it contracts and pulls the needed amount of coolant back into the rediator.

If your problem was from a blown head gasket pressurizing the system, it would continue pushing out water as long as it was running due to the added pressure. Cylinder compression is WAY more pressure than a radiator holds. That kind of pressure would likely cause a serious overheating issue before long or even blow a hose...