2010HarleyF150

I just changed my antifreeze and thermostat after 7 years and 62,000 miles and I researched everything before I got started and here's what I did and what I noticed while I was doing it. First off my coolant looked yellow in the reservoir and I went into my owner's manual and it called for two types of antifreeze, Motorcraft Premium Gold or Motorcraft Specialty Orange, second I looked up the specs for the thermostat and it called for 195 degree. I went on several forums and saw people running 170 and 180 degree thermostats and looked into various types of antifreeze including Zerex that claims it's compatible with Ford cooling systems. One more thing I did was look up the capacity of my cooling system and the owner's manual said 16.9 quarts, on some sites I saw the capacity called out at 20 quarts. I went to Walmart and got 13 gallons of distilled water and two gallons of Prestone Concentrate with COR-GUARD that states it is compatible with any color antifreeze and it's 5X more effective at protecting against corrosion. I bought a new high end thermostat and O-ring from NAPA rated at 195 degrees and two containers of Prestone Flush+Cleaner.

During the draining process I only got about 2 1/2 gallons of "orange" coolant out of the vehicle and added the two Flush+Cleaner and about 2 gallons of distilled water and after burping the system closed it up and ran it for 30 minutes and even took it for a 20 mile ride with the heat at 90 degrees to make sure everything got mixed properly and let it sit over night. When I drained it again in the morning I still noted orange fluid coming out but I went ahead and added about 2 gallons of 50/50 Prestone and again ran the vehicle for 30 plus minutes and took it for a short wide where I could get the revs up on the engine with the heat on. After the engine cooled down I drained off a gallon of fluid into a clean container and it was clean yellow like Prestone should be but when I checked it with my hydrometer and got about a 25/75 mixture so I topped it off with 100% Prestone antifreeze.

After running the vehicle for excess of an hour and taking a ride I checked the coolant with my hydrometer and got -22 degrees F and +262 degrees F for freeze point and boiling point which coincides with what I got when I checked the freshly mixed 50/50 solution, I believe my hydrometer is slightly off because Prestone claims protection to -34 degrees F but where I live -22 degrees F even with windchill is more than adequate.

I learned several things about my during this process, 1)Prestone with COR-GUARD is fine for the application when compared to other more expensive alternatives, 195 degrees is the optimum operating temperature for the 5.4L Triton V8, and only about 50% of the fluid is drained from the radiator, I know there is a block drain plug but I didn't mess with it. After over seven years and 62,000 miles my antifreeze was probably still good and it was in fact the Motorcraft Specialty Orange installed at the factory.

Going forward I will on an annual basis just drain and install two fresh gallons of 50/50 mix Prestone with COR-GUARD and replace the thermostat every four years to be safe but I don't see a need after my observations to ever do a complete flush and fill again because even this time it was a waste of time and money however now I am certain what type of antifreeze is in my cooling system.

Any comments are welcome but please don't tell me that Prestone is going to ruin my engine, I've been using it with great success for several decades .

Siber Express

Actually the Ford Mechanic that works on our 6.0 s at work changed all of our 6.0's to Prestone with a pint of Motorcraft Coolant Additive

73fxe

What are You going to do with the other 11 gal. of distilled water ?

2010HarleyF150

Good Question:

I think I left a step out, I actually did one more flush with straight distilled water so I think I have seven gallons left, they will come in handy but fall short of having enough to flush my Lincoln MKS, the wife's Edge and her "truck" a Honda Ridgeline.

DMC60

Any updates on the Pros-Cons of using the Prestone with Corguard in late model F150 Trucks? Have any negative mechanical issues with the cooling system been reported? I have done a significant amount of reading and from what I have read, the Prestone with Corguard is actually superior to the MC Spec Orange, or Gold Equivalent. From what I gather the Corguard Coolant may provide superior protection out to 150,000 miles in most if not all light truck applications.

The White Papers on Prestones Site regarding actual testing on Ford Crown Vic, Ford Fusion look pretty impressive to me.

As a Side note: I was considering changing my Antifreeze in my 2011 F150, 25,000 miles. But I crawled under there and took a sample from the bottom of the radiator, and the coolant looks clear and the PH is 7.5-8.0. Going to get a tester and check the concentration and protection levels. So I've had this truck for 90 months and for the record the AF that is in it is factory fill.

Spiky

I had to drain some out at 7x,xxx miles due to leaks and it looked brand new. I put the new bottle next to the drained bottle and there was no difference. It did get completely changed at 100k, but there doesn't appear to be a reason to change more often than the manual's schedule of 100k. In my experience.

DMC60

Are you talking about Prestone with Coreguard? Or are you talking about Motorcraft Orange?

Spiky

Orange.