Best Coolant for 03 GMC - 102000 Miles on Dex-Cool

[Turk]

Ok Guys,

I have 102k on the original Dex-Cool on my 03 GMC Sierra 5.3l and it's time to change it. I'll take it to a good quality shop to have 'em power flush it.

I want the best because I use the truck as a "truck". I pull a 3k Lb. Boat A LOT and overload the Payload with heavy, wet wood quite a bit too. It also sees 75 MPH Highway speeds, 95-100 F Summers down to 35 Below Winters!

I also want the truck to go to at least 250k reliably.

So, without the age 'ole bashing, which coolant is the "Best" for this application...??

Green or Dex-Cool or some aftermarket...??

Thanks

 

[unDummy]

Stick with Dexcool. Change it out in 50k intervals!

 

[onion]

If it were mine, I'd flush the system real good with water, then refill with a green heavy duty Texaco antifreeze.

But if you're going to stick with Dexcool, then I'd strongly reccomend that you discard any notion of "extended life" with this antifreeze. I'd change it every 2 years or 30k miles... 'cause I've dealt with Dex-sludge too many times. Coolant is relatively cheap and easy to change... unlike clogged radiators and/or overheated engines.

 

[Big Jim]

I would not use Texaco green unless the formulation has changed. It is the epitome of "green snot of death" once it ages enough for the silicates to fall out.

If Dexcool has not been a problem for him on that engine it is superior.

 

[onion]

Texaco heavy duty antifreeze is low silicate. There's more than one kind of green antifreeze... neither of which cause dex-sludge.

 

[Big Jim]

Then the formula has changed. That wasn't the case when it was still factory fill on Fords. I've had to flush many of them.

 

[Turk]

Hummm...

I almost defaulted to Dex-cool, but now need to investigate the Texaco Heavy Duty.

I should get it done in the next week as I am going to be pulling the 3k Lb Boat a lot.

 

[George7941]

My advice would be to stay with Dexcool.

I have 280k mi on a 1997 Chevy Diesel Van and Dexcool has performed flawlessly in this van. The insides of the cooling system are still sparkling clean and I have had very few cooling system problems. The themostats stuck open a couple of times(better than stuck closed), the rad side tank developed a fatigue crack at the engine oil cooler line, and, finally, at 280k mi, my water pump is leaking.

I replace the Dexcool every 80k mi/2 years. As long as you keep the coolant level topped up and any leaks are promptly attended to, Dexcool works very well.