need-for-speed

I've had Dexcool in several vehicles: 2000 Corvette, 2005 Tahoe, 2008 Tahoe, 2008 Corvette, 2008 Silverado. Never had any problems. I know many people with late model GM cars (which means they have Dexcool). Don't know of anyone who has had a problem.

The only place I've heard of problems with Dexcool is on the internet.

LS WON

Toyota also uses Dexacool.

need-for-speed

I would use distilled water too, but there is a twist. After one drains the old coolant, the thing to do is to run the car with the petcock drain open and the garden hose in the top. Run until clear water is draining out of the bottom.

Now, unless you remove the drains from the block, there will still be about 2 gallons of water in the block after it stops draining from the radiator. So, you want to add 100% antifreeze with no water to fill the sytem in order to achive the 50/50 mix.

need-for-speed

Yes you can. I just did it.

LS WON

How did you do that?
There is that plastic reservoir in the way.
I saw dealership do it this way by just removing pet **** and then adding new coolant then removing any air bubbles/

need-for-speed

Just open the petcock and fill at the reservoir bottle with the garden hose and let the engine run until it runs clear.

Re-fill through the reservoir cap. Now it did take a while to get all of the coolant (about 1.8 gal) into to reservoir - waiting on the thermostat to open /working out the air pockets. But that is not unusual, even in old school cars. Next time I'm going to use the gadget described in post no. 2 in this thread:

http://forums.corvetteforum.com/c6-c...t-air-out.html

LS WON

So you did go throught the plastic reservoir bottle?
I did this on my other car with regular conventional cooling system with opening on top of radiator and petcock on bottom. I used garden water with hose and noticed after doing this in time my radiator ended up with barnicle like crust growing on the inside. It was a brand new radiator. Is it possibe that the hard water did this?

need-for-speed

Yes, I filled through the plastic resorvoir while it drained out the bottom of the radiator. If you had the white crust, I'm sure it was from the hard water as you mentioned and had nothing to do with the method you used to flush.

Antifreeze is supposed to have inhibitors to prevent the issue with minerals, but who knows. I've seen the white crust in radiators as well on some of my cars in the past but they had lots of miles on them.

You shouldn't have that problem with your '05 as long as you flush every 5 years (or less).

LS WON

No this is on another car that I bought a new 3 row radiator when I used hose with the water we have that is hard but that's the only way to do it regardless of whatever type of water you have in your area.