Well first off, what year is your car? If it's 1995 or older, no need to use Dexcool, just the regular green (or now yellow I guess) coolant.

If it's 1996 or newer, it was filled with Dexcool from the factory and it would be best to use Dexcool. The reason it's not needed on an earlier car that was filled with green coolant is the internals of the engine are already plated with silicates. Dexcool will provide no extended drain intervals here, and that was its original purpose. There's no harm in changing it sooner, but the official change interval for Dexcool is 5 years or 150,000 miles. Most of the time, people reach 5 years before they reach 150,000 miles. And this isn't THAT much longer than other coolants -- they have always been recommended at either 2, 3, or 4 year change intervals. 5 years isn't that long on a modern coolant.

Dexcool is orangish-reddish. But don't go by color. Mopar HOAT is also red. The color is simply a dye. Look for Dexcool...Havoline sells it, and Prestone sells it. I wouldn't personally use the Prestone Yellow stuff that is supposed to be good for everything. Anything that's good for everything is ideal for nothing.

Also, no need to flush anything. Simply drain it and refill. Put a package of the GM sealing supplements into the lower radiator hose and fill 'er up (slowly). I personally buy the gallons of full-strength coolant and pre-mix with the gallons of distilled water, for a perfect 50/50 ratio. If you're flushing, you have no idea what your ratio is. Whatever you do, just get the ratio right, even if you do use tap water. You can also buy the pre-mixed coolant in the jug, and all you do is pour it in. More expensive, but then you don't have to measure and mix.

 

I flush by opening radiator peacock and sticking hose in top of radiator. Need to get all air out at end of process.

 

How do you ensure close to a 50/50 ratio at the end?

 

Dex is bright orange like orange koolaid, literally.

That's the problem with flushing. I personally very strongly recommend against flushing. Just drain out the 6 or 7 quarts you get out and replace it with 50/50 mix.

If you feel like you really need to get the rest out then do it again in 6 months or so. I think flushing is a bad idea and you will definitely loose control of the 50/50 ratio.

 

um, mine is brown

 

Brown ????
More specifically I bet it's your factory fill up .Keep in mind, you should use distilled water w/ Dex when changing it

 

neg, new motor 1000 miles ago

 

Dex will look brownish if the sealant tabs where used.

 

Hmmm. I have to say that I put 3 or 4 tabs in mine and it still looks orange. I think it only looks like that if the tabs were put in the tank and not the hose. It causes clustering or something. I don't know but mine still looks orange and so did the factory fill that I drained. It was not in the least bit brown.

 

I think it only looks like that if the tabs were put in the tank and not the hose.

Coolant flows through the surge tank, albeit at a slower rate. It should eventually be the same color as the coolant in the block & radiator.

 

I wonder if they used that Yellow stuff from Prestone. I've never seen brown Dexcool. Neither of my two Cadillacs had brown coolant. I changed the original coolant on the '97 at about 92k miles. The coolant on my '01 is much newer, but it's still not brown.

 

Well, I wouldn't exactly call it "brown", but seal tabs will dull down the bright orange Dex color. The more of them you use, the more towards a brown it will get.

 

Dex cool from the Factory is and has been Orange or pink. GM has published Bulletins about pink colored Dex-cool. We use a AC Delco labeled Dex-Cool, Prestone Dex-Cool that are Orange. We have an aftermarket supplier that sells us are bulk oil. The Dex-Cool they have labeled Blank OIL CO is RED. When they first came out with it the jugs came short filled like 3/4 full. Quality