Orange coolant in radiator

[Caman96]

DO NOT mix Dex with anything! Top it with Dex or flush and refill with the green stuff and distilled water

Obviously I meant 50/50 Dex which can be mixed with Dex.

 

[1998_K1500_Sub]

Do yourself a favor. when you do flush it, switch to the green coolant. the dexcool eats the intake gaskets. change it about every 3 years. i have 7 obs's and all are green coolant and guess what "NO INTAKE GASKET PROBLEMS EVER ".

Using a modern long-life antifreeze should not pose a problem if one has already replaced the intake gaskets (as many of us have, particularly gaskets which saw Dexcool from the factory), and using a long-life coolant is doing yourself a favor from a maintenance perspective.

Dexcool and other coolants in the past, such as Prestone long-life from the 2002 era, introduced the use of 2-EHA, aka 2-ethylhexanoic acid, as a rust and corrosion inhibitor.

2-EHA degraded the gaskets in a lot of vehicles which, in turn, was reportedly the source of the coolant loss / leaking gasket problems. I swapped Dexcool out of a 1999 GM 3.8L V6 early on (around 2002) and used... Prestone long-life, just to later learn both used 2-EHA. So of course, the intake gaskets developed a leak before much longer, and were replaced.

Modern gasket compositions have evidently overcome the detrimental effects of 2-EHA.

To date I use Prestone's "Dexcool" in my Suburban and S10 pickup. I'm guessing I could use Prestone's long-life too; I haven't compared their labels but I wouldn't be surprised to find their additives are similar if not identical.

 

[hobbit319]

If you are unsure as to what is in it, but want to add antifreeze, add the yellow "all makes" antifreeze. It mixes with all colors without any issues.