Questions: twin turbo-charged, 3.5L V6 DOHC 24V Eco-Boost

[ecoboost_xsport]

Cor-Guard sounds like some technology/additive, not a specific type of anti-freeze. There are millions of Ford and GM vehicles using Dex-Cool/Orange without heater core issues. My old Fords that used the green 2-year stuff would develop heater core issues. I believe the problem with Dex-Cool was the use of the old school radiators that allows air to sit in the system. The newer plastic degas bottles pretty much keep the entire system submerged in Dex-Cool so it prevents that nasty corrosion. I am not sure about the Transit design but I wouldn't put it past the heater cores not being below the degas bottle or something similar. My Fusion Sport would make gurgling noises if I filled to the mark on the bottle, so we found that overfilling the bottle solves that problem.

Yes, it is an additive. And the problem with using Dex-Cool in a system designed for the green coolant had nothing to do with air. Green coolant and any form of OAT (dex-cool) coolant are VERY incompatible. If a proper flush wasn't performed than the two form a sludge. And not sure what you mean by "submerged" as the coolant system (in ANY variant) is a closed loop system...with or without degas bottles.

And understand that the new yellow stuff is still "dex-cool" now with the phosphate additive. Which is what I mentioned earlier that the Prestone WITH Cor-Guard (apologies for forgetting the "WITH" earlier) is. Please go back and read some of those links I provided...it will help you understand it better.

 

[metroplex]

Yes, it is an additive. And the problem with using Dex-Cool in a system designed for the green coolant had nothing to do with air. Green coolant and any form of OAT (dex-cool) coolant are VERY incompatible. If a proper flush wasn't performed than the two form a sludge. And not sure what you mean by "submerged" as the coolant system (in ANY variant) is a closed loop system...with or without degas bottles.

And understand that the new yellow stuff is still "dex-cool" now with the phosphate additive. Which is what I mentioned earlier that the Prestone WITH Cor-Guard (apologies for forgetting the "WITH" earlier) is. Please go back and read some of those links I provided...it will help you understand it better.

I wasn't talking about using Dex-Cool in a system that used the 2-year green. I'm talking about OEM-filled DexCool applications. There are millions of them running around from Ford and GM without heater core problems. The old 90s GM Dex-Cool issues were largely caused by air in the system with the old school radiators that used overflow bottles so there is a large portion exposed to air. If you look at the newer (since say late 90s) Fords with degas bottles, most if not all of the system stays submerged. My 1981 T-bird with the old school radiators that GM still used up to the 90s, would have the top part of it exposed to air. It's not entirely covered. I worked on a 2003 Grand Am that used the old school radiator but with a new plastic degas bottle system and it has 200k+ miles with zero cooling issues. It finally needed a new water pump at 205k miles (original pump) because it started spitting coolant all over the place. Took 5 minutes to change that pump as it was directly on top of the motor and super easy to swap.

My 2017 Fusion Sport would gurgle at times or sounds like rushing water behind the instrument panel when we got on the throttle. We found that "overfilling" above the bottle markings would solve that problems. Sounds like not a high enough fluid to keep the heater core submerged if we filled to the factory marking. I had this issue with my 09 Cobalt SS so I "overfilled" it as well. So far neither vehicle has any issues with overheating or overflowing coolant.

The new Yellow is a P-OAT similar to the Green that Ford introduced prior to the Orange. Read all about it here:

Everything You Need to Know about Ford/Motorcraft Yellow Coolant - Ford-Trucks.com

Over the years Ford has used many Motorcraft products and the latest Yellow P-OAT coolant is the most advanced offering so far!

www.ford-trucks.com

I'd probably give the Prestone American Orange a try in the future, the 10-year/300k mile sounds nice.

 

[Crates]

I looked up the data and long term test results on the new yellow p-oat coolant today, it does provide significantly improved corrosion protection over the previous (oat) version. I will be using it from now on whenever I am draining or flushing any coolant systems.