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Discussion Starter #1 (Edited)
The coolant looks like new. From what I've read on the internet, it might be best to leave well enough alone even though the coolant is 10 years old.
What do you think?

Also, how much longer could I run the original coolant? I'm guessing to at least 60k or more miles.

2006LS, 31k miles, recently bought at an estate sale.

Thanks
 

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I'd change it. It's like 240k km or 5 years. Whatever comes first.
 

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Discussion Starter #3 (Edited)
Thanks Money Man

I've read that its 100+k miles or 5 years. But like I say it looks new and from reading quite a bit on the internet, many recommend leaving it alone as the possible introduction of air into the system (according to GM) when switching it out can cause Dex cool to sludge.

"According to internal GM documents,[citation needed] the ultimate culprit appears to be operating vehicles for long periods of time with low coolant levels. The low coolant is caused by pressure caps that fail in the open position. (The new caps and recovery bottles were introduced at the same time as DEX-COOL). This exposes hot engine components to air and vapors, causing corrosion and contamination of the coolant with iron oxide particles, which in turn can aggravate the pressure cap problem as contamination holds the caps open permanently."

In any case, my car only has 31k miles on it. By the looks of the overflow tank, air has not previously entered the system as it appears to be pink, like new.

The Cobalt is not set up to easily purge air out of the cooling system...that is why I'm considering leaving it as is. Maybe the coolant can somehow be tested to find out if it still meets specifications?

Anyone else have any input to my original question?

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I did my waterpump and let the thermostat open twice. Problem solved.
 

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Discussion Starter #5
Dug around the internet and found this information re Dex cool:

"As for deciding when to change your antifreeze, don't go by miles or you WILL certainly have seal and mechanical failures. One interesting spec I found is to use a multimeter. You put your negative probe to the negative post on your battery. You then place the positive probe in the neck of your radiator, making sure that the positive probe touches nothing but the antifreeze. Make sure the coolant is warm but not HOT (this is for SAFETY reasons as well as accuracy of your readings. Always be careful when opening the radiator cap on a warm engine). Your readings (regardless of negative symbol on readout) should be:

0.2 V to 0.5 V - antifreeze is still good
0.5 V to 0.7 V - antifreeze is borderline
0.7 V or greater - antifreeze is unacceptable.
You can also use test strips (available at a quality auto parts store for $5 or less), they work on both green and red types too. But if you already have a multimeter, why go buy test strips? The multimeter is the more technically accurate method anyway. "

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Is there any reason I couldn't check the coolant using a multimeter as noted above? and if the antifreeze is still good, why should it be changed, even though it is ten years old?

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Never heard of that testing method but it's worth a shot.
 

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That testing method is totally legit, but here is my 2₵ if your car is 10 years old with original fluids my advice is change it for new fluid. The cost is minimal and you will be worry free for the next 10 years provided you replace it with GM DexCool. You may want to replace brake fluid at this time too. .... May also want to replace gas if it's been in the tank for more than 4 years.
 

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Discussion Starter #9
The PO kept all her receipts. Got them from her nephew. Aside from having the air cleaner replaced, the only thing she did was to have the oil changed once a year. All three recalls on the car were performed.

First thing I plan to do is replace the brake fluid. I replace brake fluid every two years in my vehicles.

I do know the car was driven occasionally, even during the past couple of years, so the fuel should be good...but I'm going to top off the tank right away. Tank was 7/8 full when I bought the car.

Thanks again, everyone, for all the advice
 

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The PO kept all her receipts. Got them from her nephew. Aside from having the air cleaner replaced, the only thing she did was to have the oil changed once a year. All three recalls on the car were performed.

First thing I plan to do is replace the brake fluid. I replace brake fluid every two years in my vehicles.

I do know the car was driven occasionally, even during the past couple of years, so the fuel should be good...but I'm going to top off the tank right away. Tank was 7/8 full when I bought the car.

Thanks again, everyone, for all the advice
dont forget the cabin air filter

also you can use the strut tower jump ground point instead of battery -
 

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i might need to change mine after reading this post lol, i dont think my car has had the fluid changed since 2006
 

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Most cars don't until there's a problem. That's not how it's supposed to be
 

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Dug around the internet and found this information re Dex cool:

"As for deciding when to change your antifreeze, don't go by miles or you WILL certainly have seal and mechanical failures. One interesting spec I found is to use a multimeter. You put your negative probe to the negative post on your battery. You then place the positive probe in the neck of your radiator, making sure that the positive probe touches nothing but the antifreeze. Make sure the coolant is warm but not HOT (this is for SAFETY reasons as well as accuracy of your readings. Always be careful when opening the radiator cap on a warm engine). Your readings (regardless of negative symbol on readout) should be:

0.2 V to 0.5 V - antifreeze is still good
0.5 V to 0.7 V - antifreeze is borderline
0.7 V or greater - antifreeze is unacceptable.
You can also use test strips (available at a quality auto parts store for $5 or less), they work on both green and red types too. But if you already have a multimeter, why go buy test strips? The multimeter is the more technically accurate method anyway. "

----------------------------------------

Is there any reason I couldn't check the coolant using a multimeter as noted above? and if the antifreeze is still good, why should it be changed, even though it is ten years old?

Thanks
Interesting- good tip. But, I suspect even a degree Celsius will affect voltage reading. It is all about conductivity, and the warmer, the higher conductivity.

We need to get a more accurate table for readings. Saying "warm but not hot" is woefully inadequate for accurate readings to make a determination. Thats my bit on the science behind conductivity, but I still am learning about coolant efficacy.
 

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Discussion Starter #14 (Edited)
Interesting- good tip. But, I suspect even a degree Celsius will affect voltage reading. It is all about conductivity, and the warmer, the higher conductivity.

We need to get a more accurate table for readings. Saying "warm but not hot" is woefully inadequate for accurate readings to make a determination. Thats my bit on the science behind conductivity, but I still am learning about coolant efficacy.
Thanks

Below is one of the site from which I got the information. According to the site, this is a GM approved method for testing the coolant. Unless someone can provide specific temperature information, I'll probably just test it when it is warm and accept the test result..

https://www.getahelmet.com/jeeps/maint/dexcool/
 
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