Flush it reaaaally good. I mean, REALLY good. Then fill it with universal or the old green stuff.

I run universal in everything, but specific to your use case is the 2000 Silverado 4x4 5.3L w 489k on the dash.

We had the orange GM stuff fail in a 2000 C2500. Became gummy and caused a multitude of issues. Flushed it and switched to the green stuff pre-2010 and didn't have a problem again until the engine spun a rod after someone put synthetic in it after 350k miles... Put the green stuff in the new engine from the start and have had no issues.

 

Since 1996 GM has used Dexcool, do not use anything else as corrosion will result. Early years 1996 to 2001 has some issues but those have been resolved.

 

Dexcool is designed to protect the alum. radiators in the trucks. Using anything else puts your radiator at risk of developing bad leaks.
Maybe if you get a brass radiator, you can run the green stuff w/o any concerns, I dunno. I'll run the red junk until I find a better solution.

 

From your owners manual:

 

my 2000 Silverado april 2000 and now today . I did not use any coolant damage 180K miles .
I replaced the dexcool 2 yrs 2002 ... the coolant is 65% then distilled water 35% ... then I flushed out the heater core ...
then full up the coolant then open the coolant cap run the engine then rev the engine of the normal temp .. then the air bubbles are removing it .. then the coolant is working very good..
I did it of the factory 2yrs .. then I did it 4yrs every 4 yrs ... looks great ..
also have the replace the T stat ..

 

I am using Prestone All Vehicles, very good stuff.

Dexcool is what your vehicle calls for but there is plenty of horror stories about it. Whatever you do if you choose to go to Dexcool be very sure it is thoroughly flushed you cannot confirm what is in it so do not risk it. Dexcool does not turn pink.

The only time Dexcool will turn pink is if it was mixed with a different coolant or you have a transmission cooler failure and transmission fluid is making its way into the cooling system.

 

Toyota is Pink...

 

my toyota truck has the pink coolant .. I went to the dealership and the toyota coolant is the same specs of the dexcool !
same chemicals DEXCOOL/TOYOTA ANTIFREEZE ..

 

I concur with OpalLacod.

I used to have a 00 with 4.6L. I had spoken with my mechanic about switching coolants to ethyl-glycol. He confirmed it was not a problem providing the system is completely flushed of the Dex-Cool which I did. I sold that truck in 2018 with 265k miles and never had an issue with the cooling system.

 

Everyone should be using this coolant......
• Biodegradable• Phosphate-, nitrate-, nitrite-, silicate-, borate- and amine-free
• Compatible with all other antifreeze and coolant colors
Low Toxicity Antifreeze and Engine Coolant

 

Everyone should be using this coolant......
• Biodegradable• Phosphate-, nitrate-, nitrite-, silicate-, borate- and amine-free
• Compatible with all other antifreeze and coolant colors
Low Toxicity Antifreeze and Engine Coolant

$60!...and you know it will cost even more up in the land of Beer and Bacon....Everything cost more up there!

 

When dexcool first came out is when you heard of problems and the biggest issue was contamination. Of course many blamed the new dexcool. Most GM vehicles at the time had the coolant overflow bottle and the windshield washer bottle were right next to one another. It was very easy to open the coolant bottle and dump in washer fluid.

Since I've been living in Florida for the last 32 years, I like to buy the premix coolants. It never freezes here and I do not drive to snow country in the winter. When I lived up north, I used the concentrate to get a better handle on the % of coolant vs water.