Coolant Confusion

[THE DONALD]

I have a 2011 Tahoe and I am in the process of replacing the radiator. I have had this car since new and to my surprise I found that the coolant is green. The OEM coolant is supposed to be the red DexCool. This car has only had one issue with coolant with a hose leaking and the dealer replaced the leaking hose And apparently topped off the coolant according to the receipt. The question is, could there have been Tahoes filled with the non DexCool coolant as factory fill ? Now since I’m replacing the radiator, should I flush the green coolant out and switch back to DexCool? If the dealer mixed green antifreeze with my DexCool . Would The coolant be bright green?Your answers would be appreciated. Also since I’m changing the radiator should I also replace the thermostat. The car has 111,000 miles.

 

[THE DONALD]

I have a 2011 Tahoe and I am in the process of replacing the radiator. I have had this car since new and to my surprise I found that the coolant is green. The OEM coolant is supposed to be the red DexCool. This car has only had one issue with coolant with a hose leaking and the dealer replaced the leaking hose And apparently topped off the coolant according to the receipt. The question is, could there have been Tahoes filled with the non DexCool coolant as factory fill ? Now since I’m replacing the radiator, should I flush the green coolant out and switch back to DexCool? If the dealer mixed green antifreeze with my DexCool . Would The coolant be bright green?Your answers would be appreciated. Also since I’m changing the radiator should I also replace the thermostat. The car has 111,000 miles.

ALSO. Do you change the thermostat housing WITH the thermostat?

 

[CaptainAmerica1]

Flush, fill with dexcool, don’t change the housing unless there’s something wrong with it.

 

[OR VietVet]

Flush, DexCool, thermostat and I am one of those guys that does change the thermo housing when I do them.....just because. No harm in not changing the housing, like @CaptainAmerica1 said, if there are no problems. I just like new STUFF.

 

[Dustin Jackson]

If they mixed coolant you would know because I have heard it becomes sludgy. Its possible that during that repair the dealership just replaced all of the orange coolant with green coolant. If it were me I would do whatever involved the least amount of work.

 

[Blackcar]

I have a 2011 Tahoe and I am in the process of replacing the radiator. I have had this car since new and to my surprise I found that the coolant is green. The OEM coolant is supposed to be the red DexCool. This car has only had one issue with coolant with a hose leaking and the dealer replaced the leaking hose And apparently topped off the coolant according to the receipt. The question is, could there have been Tahoes filled with the non DexCool coolant as factory fill ? Now since I’m replacing the radiator, should I flush the green coolant out and switch back to DexCool? If the dealer mixed green antifreeze with my DexCool . Would The coolant be bright green?Your answers would be appreciated. Also since I’m changing the radiator should I also replace the thermostat. The car has 111,000 miles.

If this was done at GM dealer, they for one know what kind of fluid your vehicle takes it in owner's manual plus as you said you always had Dex Cool in vehicle. They are the ones to make this right.

 

[swathdiver]

I wonder why a GM shop would even have green coolant? Dexcool has been the norm since the 1990s.

 

[CaptainAmerica1]

FNG’s!?

 

[B-train]

I'm a fan of green. I always dumped dexcool in the early 2000's for green. Dexcool back then just ATE EVERYTHING!! I believe the newer formula is much better on things.

In the generator world, most everyone uses a good glycol based coolant (green, red, blue) and it works great. Since your truck has been flushed to green, I would personally stick with it and then you can add any glycol coolant in the future as needed.

As stated above, if it looks like sludge, then flush and refill. Just know that if you try to go back to Dexcool, you need to flush the whole system or will end up with sludge again.

 

[Geotrash]

I have a 2011 Tahoe and I am in the process of replacing the radiator. I have had this car since new and to my surprise I found that the coolant is green. The OEM coolant is supposed to be the red DexCool. This car has only had one issue with coolant with a hose leaking and the dealer replaced the leaking hose And apparently topped off the coolant according to the receipt. The question is, could there have been Tahoes filled with the non DexCool coolant as factory fill ? Now since I’m replacing the radiator, should I flush the green coolant out and switch back to DexCool? If the dealer mixed green antifreeze with my DexCool . Would The coolant be bright green?Your answers would be appreciated. Also since I’m changing the radiator should I also replace the thermostat. The car has 111,000 miles.

There are some formulations of green coolant that are allegedly "compatible" with Dexcool. Valvoline oil change shops use one of them when they do a coolant flush, and I don't care for it. To me it's marketing horse$hit. I had my coolant done in my '07 at a Valvoline shop when I bought it and flushed it again myself a few months later with fresh Dexcool.