f'ing dexcool....

[ryan.hess]

Reddish-brown mud is all in the cooling system. Got some flush sitting in there right now (already drained what was left). Will that dissolve the dex cool mud? No overheating problems or anything like that, but god what a mess!!

Switching to green once I get all this crap out.

[sil]

yikes, man lots of dexcool problems these days
i used to think the dexcool was better due to different metals used on the motor, but now i will never touch the stuff

i allways flush every year anyways though

[onefastV6]

How often do you flush your coolant?
I flush my coolant system atleast once every 1.5 years, coolant is cheap enough and I have yet to have any issues with dexcool.

I have seen a number of cars with the mud coolant syndrome and all of them have been due to lack of maintance.

[geoffinbc]

How often do you flush your coolant?
I flush my coolant system atleast once every 1.5 years, coolant is cheap enough and I have yet to have any issues with dexcool.

I have seen a number of cars with the mud coolant syndrome and all of them have been due to lack of maintance.

Agreed the majority is due to lack of maintainence. People always let the systems run low and Dex Cool, for some reason, always gums up bad when air enters the system. The best solutiion is to run Prestone all make/model antifreeze. I have always used Prestone and the inside of my rad looks like someone polished it.

Here is the recommended Dex Cool flush procedure from GM

http://members.shaw.ca/betterthanyoutoo/dexcoolflush.htm

[ryan.hess]

How often do you flush your coolant?
I flush my coolant system atleast once every 1.5 years, coolant is cheap enough and I have yet to have any issues with dexcool.

I have seen a number of cars with the mud coolant syndrome and all of them have been due to lack of maintance.

I haven't. I just picked this car up. Go figure, I didn't check the coolant.

[tru2chevy]

The best solutiion is to run Prestone all make/model antifreeze. I have always used Prestone and the inside of my rad looks like someone polished it.

This is what I have been doing for the past year or so, and it's been problem-free.

- Justin

[IsaacHayes]

Two of my friends have problems now from dexcool. one is a 96ish lumina, other is a 2002 impala. Both have clogs in their radiators and heater cores from it. I told them, flush it or it will clog, and now they are coming to me worried why their car is over heating, and they don't have any heat coming from their heater...

[tractorman]

Since I don't feel like re-typing my rant, here's a copy/paste from my post over as chevytalk:
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Here's my experience with Dexcool: When I met my wife back in 2000, her '94 corsica had that sticky brown dexcool sludge in it. That stuff is damn near impossible to get rid of. I flushed the system, used a steam cleaner, used soap... tried damn near everything. I never got it all out- matter of fact, the car always tended to overheat in hot weather 'cause some cores in the radiator were stopped up with the sludge. Finally I took out the radiator, and sent it to the shop to be rodded out. Put it back together, filled it with green antifreeze, and it's been fine ever since- but to this day, years later, you can still see some brown sludge in the bottom of the tank.

I've heard lots of theories as to WHY Dexcool turns into sludge- air seems to be the most popular. Also, I worked at a Cummins engine shop for years, and replaced dozens of head gaskets that leaked because of Dexcool (according to a Cummins service bulletin). Green stuff doesn't turn to sludge and it doesn't make otherwise good gaskets leak... so nowadays if I get a vehicle with Dexcool, the first thing I do is flush it out and refill with good ol' reliable green antifreeze. Not a single antifreeze related problem in six years here.

Here's how my brother dealt with his '98 Cutlass's dexcool. He took my advice and flushed it all out... then he poured some Cascade (dishwasher soap) into the system, which got a fair amount of the sludge out. He removed the tank, plugged the hose ports, filled it a little way with cascade, water, and small gravel, and shook it around. He said that gravel scraped the sludge right out. I don't think I'll go to that much trouble with my ol' Corsica, but it sounds like a good idea to me.

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Here's a note for ya'll who blame dexcool-sludge on lack of maintainence. You may be right in a sense... but first of all, dexcool is billed as magic stuff that should last 100k miles. Obviously, it doesn't- and this marketing gimmick is clearly contributing to the problem. Secondly, these cars are well-known for coolant leaks (LIM), so unless you're vigilant about checking that coolant every single day (and who does that?), then at some point, odds are that you WILL be low on coolant- at which point Dexcool turns to nasty sludge from hell. Green stuff doesn't do that.

[onefastV6]

Here's a note for ya'll who blame dexcool-sludge on lack of maintainence. You may be right in a sense... but first of all, dexcool is billed as magic stuff that should last 100k miles. Obviously, it doesn't- and this marketing gimmick is clearly contributing to the problem. Secondly, these cars are well-known for coolant leaks (LIM), so unless you're vigilant about checking that coolant every single day (and who does that?), then at some point, odds are that you WILL be low on coolant- at which point Dexcool turns to nasty sludge from hell. Green stuff doesn't do that.

GM rates dexcool to I believe 5 years and 100,000 miles, they say that their tranny fluid is "life time fluid", and they have oil change systems that tell you when you should "change your oil", which is always way over 3,000 miles.

You can't always go with what GM tells you if you want a well maintained reliable vehicle.

I am sure there are many well maintained vehicles that are 10 years old using dexcool with no sludge, because the owner took the necessary precautions and flushed the system every few years.

There are many shops that offer cooling system flushes, however be aware that many consider a coolant flush a drain and refill. I recommend finding a shop that has a Wynn's or similar coolant system flush machine to help flush out the cooling system.

[tractorman]

The 5-year requirement is an interesting point. When I met my wife, her (now 'my') '94 corsica was only 6 years old with 77k miles. I think one can reasonably assume that the coolant had never been changed... but the car had also never shown any sign of leaks. Just the same, the cooling system was thoroghly sludged by the time I showed up. Maybe that sludge wouldn't have happened if she'd had it flushed a year earlier... but then if you HAVE to change and flush the coolant every few years to avoid potentially engine-destroying problems- then what's the point of "extended life coolant"?

I'll stick with the green stuff. Of course, it also ought to be changed every few years... but it won't clog the radiator if you wait an extra year.

[bszopi]

Hmm.. interesting tractorman. I'm guessing DexCool was introduced in 94, but only in limited use. Reason Isay this is because my 94 Beretta came with the green stuff...

My 98 Blazer is another story...

[gpse3400]

My '94 Z28 came with Green stuff but we later switch it to Dexycool and I have to say that is one engine that does give a hoot.. 170,000 miles and no leaks or clogs.

[ryan.hess]

You know that the system becomes contaminated with silicates if you switch from green to orange, right?

Once contaminated with silicates, you have to replace the dexcool every 2 years/30,000... Basically you don't gain anything by switching from green to orange.

[tractorman]

I never met my '94 corsica until early 2000... so I don't know for a fact that it came with dexcool. It was there when I showed up, and the wife said that she had owned the car since 20k miles in 1997... the sole repair since then had been the alternator. It's entirely possible that it was switched over to the red $hit, or that some nimrod mixed red & green at any point during the six years of the car's existence before I showed up.

Bottom line: when I showed up, the antifreeze was red, and the cooling system was full of this nasty sticky sludge. I've seen the same sludge in lots of other dexcool systems. I've been a mechanic (of big diesel things) for well over a decade now, and I've yet to see a single instance of green antifreeze doing that.

Now, I'm obviously no fan of dexcool... but there may be some advantages. I know that aluminum cooling system parts are bad about pitting if you run green antifreeze and don't change it regularly. Maybe dexcool does a better job of preventing corrosion with aluminum?

[SE'sarecool2]

Maybe dexcool does a better job of preventing corrosion with aluminum?

Maybe so, but to me that doesn't outweigh the disadvantages of the stuff. I changed mine to green at 30K(when I bought the car)and I'm gonna hit 60K soon. Drained & refilled 3 times in that span with no problems.