pfcvo

Was thinking about taking it to the stealership to let them do it, but then thought about how they are going to charge me $113 and still I wouldn't be sure if they are going to flush it with distilled water or even jack up my Z the correct way so I decided to do it myself.

Interestingly, I didn't have to jack the Z06 up, just reached across from the passenger side and using a flathead screwdriver and loosened the coolant drain plug. I used about 8 gallons of distilled water to flush out the system twice after dumping the original coolant out. For each flush I filled it up completely with the distilled water, started the engine and let it idle with the occasional blip on the throttle to get the coolant temps up and then turn off the engine after the cooling fan kicks in.

After the flushing the system twice I added a 50/50 mix of the Preston GM Dexcool certified coolant, started up the engine and let the temps increase until the fan kicks in and shut off the engine, and with the cap loose I "burped" the cooling system by squeezing the top radiator hose to dislodge any air bubbles.

After that I took the car for a drive around city and highway, with cruising temps in the norm for me (196-198 Degrees F) with about 201 degrees at stoplights. So, do you guys think I did okay with my first coolant change job?

vms4evr

What year and how many miles were on it?

The only thing to add that is recommended for a full flush. Remove the knock sensors from the block and let it drain. It makes for a more difficult job though. You did the right thing using distilled water.

pfcvo

it's an 02 with 32,000 miles. Hmm, I have never heard about the knock sensors in being able to pull them out to drain. Oh well, the two-three flushes I did netted a total of around 2.5 gallons each, out of 3 gallons total I think.

forsvette

It was always recommended on my other cars to run the heater to circulate the coolant through there as well.

JWB ZO6

I did mine the same way. I think I will make this a once a year thing.

vms4evr

If you're running DexCool there is absolutely no need to be changing it yearly unless you put 100K miles/year on the car. It's a waste of money and more antifreeze being recycled that doesn't need to be. You may not feel it's good for 5 years and 100K miles but I wouldn't be so quick to change it. I'm still on the original antifreeze. 02 with almost 40K on it. The car doesn't overheat and even with track abuse the coolant still tests out good. I'll be flushing this year since it will be 5 years old.

EGL ONE

Long, Semper Fi! and thank you for your service
Enjoy your time in College! and the Z........

MUKAK

i have 85Kon my 97 and still have original coolant fluid

and yes i do a lot of hard driving

pfcvo

Thanks for your support, good luck with your Z.

mr-z

GREAT JOB.
You don't need to Remove the knock sensors from the block and let it drain. Just run the heater to circulate the coolant through.

swchopper

Youre going to have to trust me on this one. IF you are using Dexcool, you are INSANE to change it at all. You realize that this SAME coolant, used in Heavy duty applications, much more severe than ours, is a 600,000 mile coolant for warranty purposes, and will actually extend much beyond that. It is true. But it must be Dexcool, not prestone dexcool approved, etc. Chevron/Texaco is the only one who has the license to manufacturer using this technology. It may have the GM name on it also, though.

I could go on and on, but theres not enough room and time to explain the science. But it is a fact. That is why almost all diesel manufacturers have factory fill on the same technology coolant. It is just called ELC for Diesel engines. The exact same coolant as Dexcool, except they add nitrite for liner protection in diesel engines.

LO PHAT

Just a thought here. Someone please correct me if I am wrong.

Let's say that after flushing your radiator and engine twice with the distilled water, you have 100% water in your system. You now drain the radiator and refill it with the 50/50 mix of water and coolant. To make the math simple here, let's assume that half the cooling system's capacity is in the radiator and half the capacity is in the engine block. Now that you have filled your radiator with a 50/50 mix, your entire system is only at a mixture of 25% coolant and not the 50/50 mix that is recommended.

Am I right or wrong here? I have often wondered about this on all of my vehicles and therefore do my system flushes a little differently since I don't like pulling drain plugs on the engine blocks.

LO PHAT

thehammer69

Even though Dexcool and ELC both use Organic acid technology, don't be fooled into thinking they are the same. I would never run Dexcool in my heavy duty diesel engines. If you want to know more, I can talk to a couple Engineers I know who's specialty is automotive cooling, and post up the differences.

Anyway, to get back on the Corvette topic...Yes, Dexcool is rated for 100k...but it also has a time limit too. I would imagine most C5 owners probably reach the time limit before the mile limit.

Hammer

dwjz06

I would not go beyond the 5 years. To me the better safe then sorry rule applies. The distilled water is best.

swchopper

The hammer69. You should not use Dexcool in your HD application, JUST because of warranty etc. Although, you could. No I am not fooled - because yes, Dexcool and ELC are the exact same minus the red dye and nitrite additive. You can talk to your engineers. If they tell you otherwise, they are incorrect. In no way am I trying to be argumentative. But facts are facts, and people do not understand the truth. I do not claim to know it all, but I can sure find out as I do have contacts for the developers/enginees of the Dexcool/ELC products.

dwjz06: Class action lawsuit: 02/07. Federal Judge rejected the lawsuit. The only lawsuits that are pending are in certain states. All lawsuits have been rejected . In short, the claims are false/incorrect.

2 main points here: with dexcool, you MUST keep your system full at all times. Dexcool will NOT protect parts from steam in the "empty" space.

2. When switching from a conventional green to a Dexcool/ELC coolant, it is well advised to tighten all clamps/hoses, as you may see small leaks. In conventional green, the silicate can create a "seal" in crevice corrosion which occurs where hoses fit mounts, etc. But silicate is not good, as it is a "solid" which causes corrosion, wear, and silicate build up.


OK. Im done with my soapbox. Sorry!

dwjz06

Thanks for the update. I got a call on my old car from the suit folks. I guess it is done as I have not heard anything further.

Have you heard of any other head gasket failure or issues after changing over to Dexcool. I am interested still even though the old car went to the junk yard. Thanks, Don

rustyguns

another smart guy at corvetteforum

swchopper

I dont know about smart I just happen to sell lubes/coolants/fuel for a living. I was lucky and just spent 5 days in training at Southwest Research Institute in San Antonio. This is where they independently test oils/coolants, etc. For example, when I was there, they had like 30 diesel engines all running on dynos testing different oils to meet the new CJ-4 specs. Quite an education and cool laboratory.

Anyways. Coolant is one of my strong points, as its really quite simple. As to specific head gasket problems, etc. I dont know of any.
If anyone claims there gaskets leak because of Dexcool, etc. it is incorrect. ALL coolant is ethylene glycol. Therefore, one coolant wont "eat" gaskets more than another. But as I said, the conventional green coolant does have silicate which lays down a layer of silicate, which can actually get in crevice corrosion (where gaskets meet metal, or hoses meet intakes, etc.) and create a "dam" to leakage. However, the silicate does much more harm than good.

When you go to a carboxylate coolant like dexcool, there are NO silicates, and therefore, pre-existing corrosion may start to show itself with small leaks, but these are only in place which can be tightened to resolve itself.

That probably just made no sense. But I tried. Hard to type long science explanations in a short space.

dwjz06

^ What about the PH balance and or acidic qualities? Are there any?, and under a low level of coolant situation what happens to the dexcool which as you stated does not do well with the steam or vapor? I have seen some sludge build up after some miles on my old car. Thanks, Don

rustyguns

i just use redline water wetter and distilled water

my temps dropped 20 degrees after changing to the redline

anything i should worry about? ...i live in Az no freezing here