Very little Heat?

[fastTa]

There is absolutely nothing wrong with Dex-Cool. It got a bad rap because the vast majority of people do not mix it 50/50 with water like they are instructed to. Most people will tell you they just poured in one gallon of Dex-Cool and then topped off the radiator with water.

Dex-Cool is more sensitive to being mixed properly than the green stuff, so this makes it even that much more important. If you dilute the Dex-Cool too much with water, you increase your chances of the coolant/water mix becoming acidic and electrolysis occuring. This is the number one cause of heater core and radiator core failure.

If you have to rich of a mixture(too much Dex-Cool), you significantly increase your chances of crudding up your coolant system.

I personally think the Dex-Cool claim of 5 years or 150k miles was an overshot. I would still flush and change the Dex-Cool every couple of years. Make sure you mix it as close as possible to 50/50.

Most pro's that I have talked to and/or know, discourage the use of distilled water in an automotive coolant system. The primary reason is that purified or distilled water, can actually have a defervescence effect, effectively raising the boiling point of the coolant system. Distilled water not only has a higher boiling point than that of common tap H20, but it's boiling point is very unstable.

Also, distilled water can often become deionized upon the distillation process. This is also not good for a coolant system, because it will exacerbate the potential for damaging electrolysis to occur.

[jeffs97z28]

My local Chevrolet dealer is the only shop that has maintained my cooling system for the last seven years, If the mixture is so touchy that they can't get it right, they shouldn't be using it. I thought I would take my car there because they should be experts with the LT1 etc, LOL!!!! And you are probably right about flushing and changing it every 2 years, but then what is the point, any cheap antifreeze will hold up for two years if mixed correctly.
I'm sorry Dexcool is Dexshit in my book. Most people I've talked to have told me that their mechanics are telling them to get the Dexcool out of there system as soon as the 3/36 warranty is up.

[toddwirges]

The biggest problem with using green coolant in a Dex cool factory setup is that there is no indication that the coolant is failing.

Dex cool was designed to extend the service life of the cooling system. It was thought that such a long service interval would be a good thing. The problem is, the average person doesn't pay attention to anything other than that 150k mile service interval.

Need to top off the overflow? Fine I'll use tap water. Need to add some coolant? I'll just add a little green coolant. Have a hose problem or a leak and otherwise contaiminate the Dex cool? These are all bad things and are the reasons the Dex cool turns to sludge.

Can you use green coolant? Yes, and you probably should if your cooling system has been compromised in any of the above ways. Dex cool doesn't "play nice" with other coolants or contaimination so once you compromise it, flush it and stick with the green stuff.

The problem is, usually green coolant shows the need to change it because rust shows up. LS1's are all aluminum... so you won't see this. So the green coolant is actually no longer providing corrosion protection, but you have no visual sign of problems.

If your Dex cool setup is hosed, flush it the best you can, go to the green, and remember to change it every 1-2 years and be done with it.

[fastTa]

My local Chevrolet dealer is the only shop that has maintained my cooling system for the last seven years, If the mixture is so touchy that they can't get it right, they shouldn't be using it. I thought I would take my car there because they should be experts with the LT1 etc, LOL!!!! And you are probably right about flushing and changing it every 2 years, but then what is the point, any cheap antifreeze will hold up for two years if mixed correctly.
I'm sorry Dexcool is Dexshit in my book. Most people I've talked to have told me that their mechanics are telling them to get the Dexcool out of there system as soon as the 3/36 warranty is up.

As long as the Dexcool is properly maintained, it actually has the capacity to prevent internal corrosion better than the green stuff. The green stuff and Dex-Cool are both ethylene glycol based, however Dex-Cool has a chemical makeup that allows it to better prevent corrosion.

If a mechanic is resorting to the suggestion of just simply removing Dex-Cool as soon as the warranty is up, it's seriously time to find a new mechanic. The problem is not the Dex-Cool, it's the owner. I've worked on dozens upon dozens of GM cars that were maintained well by the owner and never had a single problem with their Dex-Cool cooling system. You just need to inspect a Dex-Cool cooling system every so often just as you would any other cooling system.

If you hate Dex-Cool so much, then there is always the Prestone Yellow. It seems to be another option.

[toddwirges]

Dex cool is better, but any contamination greatly reduces it's effectiveness to at or less than that of traditional 2 year green coolant.

That's the key point that escapes people. They compromise the system and then expect that it will still last 5 years.

Not disputing, just a point of clarity.

[fastTa]

An automotive chemical and heat exchange testing company named Amalgatech performed some tests with Dex-Cool and the green conventional coolant. They mixed the Dex-Cool with the green stuff and then subjected the mixture to a sample of fresh aluminum. Their aquired data from the tests suggested that the aluminum was corroding at an accelerated rate as compared to the fresh aluminum being exposed to pure Dex-Cool or pure green stuff. So I would agree, mixing the two is probably not a good idea, especially in a all aluminum motor such as the LS1.

Zerex G-05 appears to be the ultimate coolant right now for durability and corrosion resistance. It utilizes a hybrid organic acid technology to minimize inhibitor depletion. It has no compatibility issues even with Dex-Cool and it even conforms to the ASTM D6210 specification, so it can be used in diesel truck coolant systems.

If one were to switch from Dex-Cool to another type of coolant, I would think this G-05 would be the top choice.

[Christopherrr]

There is absolutely nothing wrong with Dex-Cool. It got a bad rap because the vast majority of people do not mix it 50/50 with water like they are instructed to.

Prestone has a 50/50 mixture of Dex-cool. I didn't switch to the green stuff and poured this stuff in after a flush. No crud and still looking good. Worth IMO.

[jeffs97z28]

I hate to complicate matters, but there was no indication of sludge, crud etc in the coolant in my system, When I took it in for a flush and fill last fall the dealer called me up and said I did not need it because my coolant was clean.
I finally took it somewhere else and they flushed it put in the green stuff and I had heat for about six weeks. I've either got a head gasket gone [ shit ].
Or the plugged heater core really makes this cooling sysem do weird things because when I checked the radiator yesterday it was down about 3 inches and I still had coolant in the overlow tank. I filled it and bled it, now I have a little heat and shes back to overheating up when idling. THey said my water pump was good and that I did not have a bad head gasket. The only thing I can think of is when the heater core is plugged coolant gets kicked into and out the overflow when I'm driving due to a less than full heater hose line from the outlet of the core. Finally there is enough of a pocket that it does not draw back from the overflow tank. One way or another I will find out soon because I'm going to flush it again myself and see what happens.

[EquatorHeat00]

Old post I know.
My heater for 2 weeks now only blows out cold air. Is this caused by my bad headgasket? All I know is last year at this time it wasn't working that great, and at the time I had a 180 thermostat now have a 160, also my headgaskets were fine at that time for about 4.5 more months.
Is the heater tube that needs flushing the 1 with the mesh material around it attaching to a vanilla colored plastic piece towards back of engine compartment? This is the only tube on the passengers side by the firewall that looks like it could be it.

[jeffs97z28]

This is what I found out was wrong with mine. The heater core was getting plugged with what I believe was old DEXCOOL that was starting to gel up inside the system. Other symptoms can be, engine running hotter than normal, A low coolant light and level comming on. And little, or no heat.
The good news is that the heater core is pretty easy to flush out. I just disconnected the heater hoses at the heater core, put 6feet of new heater hose on the inlet and outlet, took the garden hose and flushed away. The harder part is if this takes care of your problem you really need to get all of the old DEXCOOL out of the system and replace it with new or regular anti-freeze. I went with the green stuff in mine and it has been fine for a year now. Don't forget you need to get all of the air out of the cooling system after working on it. An air pocket can also effect cooling and the amount of heat you get. Unless you get lucky don't expect much help from your local dealer. They seem to be clueless or unwilling to admit That Dexcool can cause this problem if mixed improperly or not changed often enough. Hope this helps.

[EquatorHeat00]

My car uses green antifreeze NOT dexicool. I don't know where the heater hoses are. What do they look like? I see 1 wide hose with mesh on it is that it? I need pictures. I sure wish Ihad someone who could teach me this stuff.

[EquatorHeat00]

Wherres the heater hose? Is it 1, or 2?

[jeffs97z28]

Please don't take this wrong, but if you are having trouble finding which hoses are the heater hoses, you may want to take the car to a good mechanic or see if you have a friend who can help you. The heater core outlet and inlet come right through the firewall on the passenger side of the engine compartment. [ At least on the Z28]. The hoses are partially rubber and metal as they are molded to be routed around a host of things. Having green anti-freeze in there now does not necessarily mean the heater core is not obstructed. It could be that when the dexcool was taken out, they did not get it all. Mine had to be flushed twice. The first time I got some heat for a few weeks then nothing. When I finally flushed it all myself the problem was solved and I got heat. Good luck and let us know how it goes.