dexcool or not ?

Stick with dexcool. It is what is designed for your car. There is too much misinformation on these groups that should not be used in decision making....

If you have the 3.4L V6 with the original intake manifold gasket, you might want to get it replaced if you want to stick with dexcool. There's tons of problems with that family of engines leaking coolant onto the camshaft, corroding the bearing surfaces, causing the cam to bind and snap. The problem supposedly manifests itself around 68k miles, and there's tons of info available on the net with Google.

Re dexcool being designed for any specific engine, bull****. Most coolant is based on ethylene or propylene glycol with various carboxylate, silicate, borate, and nitrate additives to prevent corrosion. Dexcool, though having the same EG base as the green stuff, is more corrosive and has a nasty tendency to gel, reducing cooling efficiency by clogging your radiator - the advantage of it is that it degrades a lot more slowly over time, meaning that you don't need to perform the yearly flush. The green stuff is more mild as a coolant, and because you HAVE to flush it regularly if you follow regular maintainance procedures, you end up prolonging the life of your cooling system because along with the coolant, you remove some of the scale and other built up crap from your system.

Dexcool is also supposed to be better for aluminum components that the green stuff which is what people mean by designed for the engine. Green stuff didn't have to be changed yearly, the most I have ever seen was every two years and that was on the severe maintenance schedules.

That problem with the 3.1 and 3.4 engines has nothing to do with Dex-Cool. It's a gasket/sealing problem that is prone to happen regardless of the coolant you use.

I've been using Dexcool for several years, and I like it. The EPA shut down two shops in my neighborhood, so I'm paranoid about draining * any * automotive fluid. Used oil is welcome at parts stores, used antifreeze isn't.

If your water is " hard " use distilled water, and a 50 / 50 mix of Dexcool The Green stuff is hardly " green " [ enviro speaking ] I think the bad press Dexcool got is due to mineral laden water, poorly built engines, and too small capacity cooling systems. My V6 and V8 engines are content with it, and so am I.

Is Dexcool low tox? TIA.

-John Banister

NO, DexCool is at least as toxic as the green products. A low toxin anti freeze " Sierra " came and went a few years back.

The idea sounded good, the product was expensive, hard to find, and required a " swimming pool water " type test for strength. A conventional anti freeze tester gave erratic readings.

Swapping from dexcool to conventional antifreeze will also make the hose connections begin to break down, causing leaks.

| That problem with the 3.1 and 3.4 engines has nothing to do with Dex-Cool. | It's a gasket/sealing problem that is prone to happen regardless of the | coolant you use.

The problem with the 3.1 and 3.4 is related more to the high performance alloy cross flow manifold bolted on an aluminum block and head in a old fashioned push rod engine format. While the heads and manifold are water cooled because, they get hot when running, they tend towards tempature disequilibrium when the engine is switched off.

The variable rate of cooling over a long period of time comprimises the seal and allows coolant to pool in the manifold. After a good long run, if you hear a hiss in either of these engines, you look at the next car on the sales lot.

Dex-cool is specified for a reason in an aluminum engine. I would not change. Also never mix dex-cool with conventional anti-freeze as you could start a fire in your cooling system. If you are dex-cool equipped and need coolant for short duration, use water.

Also never

I agree that mixing Dex with green is a no-no, but please explain how that would start a fire in the cooling system. H

You don't really know what you are talking about, do you? Neither of the those engines have an aluminum block, but the heads and the intake are aluminum which means they expand and cool at the same rate.

Well...there you go...another diagnostic tool for me. Take the car for a good long run, and if I hear a hiss....it's the intake gaskets.

My goodness, what you do learn on the internet!

Ian

| | I agree that mixing Dex with green is a no-no, but please explain how that | would start a fire in the cooling system. | H | It starts as a chemical fire. |

Hey retard. They are both aluminum in current year. From 1996 onwards for the

3.1. Same thing your trailer is made of. The chev intake is aluminum alloy, not aluminum. Intakes are alloy molded not cast. ZZZZZZZZZzzzzzzzzz.....

You don't really know what you are talking about, do you? Neither | of the those engines have an aluminum block, but the heads and | the intake are aluminum which means they expand and cool at | the same rate. | |

You still didn't explain anything. Neither Prestone or GM warns of this danger. Actually they both say that you can mix them in the event of an emergency. But that it needs to be replaced with 100% Dexcool coolant as soon as possible.

So exactly which chemicals cause this fire? And what is the catalyst?

Brian

Got news for you. The heads aren't 100% aluminum either, they're an alloy as well. Being cast or molded doesn't define the aluminum make up.

Brian

| Got news for you. The heads aren't 100% aluminum either, they're an alloy as | well.

Being cast or molded doesn't define the aluminum make up.

Well yes it does. Alum blocks and heahs are hot-cast and cored. This is a continuous hot pore in a mold with machine coring of the bores for cyl inserts, water & oil jackets, bolt taps and other strait bores.

A 3.1 cross flow intake's polished bore is injection molded then polished before the peices have been welded together. That requires steel or tin/copper alloys for seam weld.

You don't make any sense.

Brian

I heard it gels or turns sluggy thereby loosing it?s effectiveness.

Read your original post, you idiot. You claim the engine blocks are aluminum...they aren't. The gasket failures are not due to dissimiliar metal expansion and contraction. Geez, back to school for you, my boy.

Ian