f'ing dexcool....

[Jogasz28]

My Cascade secret is out darn it....

Never add tap water to DEX never, I repeat Never ever ever even a little.

As Soon as the Intrigue get close to flushing or whenever I can afford to do so I will go green.

Ouch dex and green mixed....

I used your cascade flush "secret" after I used the regular Prestone flush when I switched from DEX to the green. I flushed my system with a garden hose 'til the water was clear.
The next day, my '95 Monte had a good sized coolant leak dribbling from the engine compartment PS rear. My heart skipped a couple of beats as I thought it might be coming from the engine's rear head we had pulled. I had just got done doing a top end (intake gaskets, oil pump o-ring). Imagine how happy I was to find the leak source was from a badly rusted/pitted metal heater outlet tube? The flush had removed all of the rust and allowed it to leak. I was glad it happened before it got really cold in NE Ohio (like right now..Brrr).
Now I have peace of mind knowing the green stuff is not going to turn to
jelly

[tractorman]

While I rarely pass up an opportunity to publicly trash Dex-crap... that's not your culprit in this case. The mayonaise under your valve cover is due to coolant in the oil- plain and simple. Any type of coolant would've emulsified just the same- seen it dozens of times.

Now... as to exactly WHY those intake gaskets leaked in the first place... feel free to blame Dex-cool. Lots of folks do, and I HAVE seen dexcool make many a perfectly good gasket leak. Granted, the GM gaskets are a $hitty design, and often split down the seam, causing a leak... so they might leak green stuff just as readily. Thing is, if the intake gaskets leak (and they always do on these engines), and you run the engine low on coolant for a bit... the green stuff won't turn to sludge like Dexcrud will.

[jacktoad]

That isn't from the type of coolant you used, that looks like you had coolant leaking into your oil.

yea, i knew that much.

what i didn't know is if the sludge that resulted was because of dexcool coolant? or was the type coolant even a factor?

thanks.

[Carlspike]

That isn't from the type of coolant you used, that looks like you had coolant leaking into your oil.

[jacktoad]

this the sludge you are referring to?

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....

interesting, informative thread. thanks.
pictured below is the underside of my Rodeo's 3.1L rocker cover after the IM went to crap. i've been lacking an explanation for why this kind of sludge formed. but after reading this thread... could it possibly be because the type coolant i had used?

[Daguse5853Z]

Some army trucks I worked on had dexcool in them and they ate brass fittings like nothing. I'm happy with regular green.

[IsaacHayes]

My 94 3100 Beretta came with Green. Be-ware that soaps can attack some rubber (like hoses, o-rings) so wash/flush at your own risk.

[Juglenaut]

My Cascade secret is out darn it....

Never add tap water to DEX never, I repeat Never ever ever even a little.

As Soon as the Intrigue get close to flushing or whenever I can afford to do so I will go green.

Ouch dex and green mixed....

[tractorman]

Wow... you must REALLY like changing antifreeze. I change mine every three years or so... maybe if I'm working on it for some reason. Better too much than not enough though. I reckon.

I like 'em french-fried p'taters.

One of my biggest gripes with dexcool has always been the FACT that it made literally thousands of Cummins N14 head gaskets leak back in the late 90's. I'm told that the formula has been changes since then to take care of the problem... and to be fair, that stuff IS run in lots of over-tha-road trucks nowadays, and I haven't seen any problems from it in recent years.

Just the same, I don't trust it. I'll stick with my green low silicate diesel engine antifreeze.

[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.

[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?

[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.

[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.

[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...

[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.