coolant/antifreeze experts needed!

[BK_89iX]

I have a coolant/antifreeze conundrum.

Owned my '97 SOHC 4WD since new, and I know the exact service history since day one. On two occasions the coolant was changed by the dealer, once for a warranty issue and once for maintenance. In both cases the invoice lists E2FZ-19549-AA (aka, FMC VC-4A). That is the older "green colored" stuff and it is the same specified in my Owner Guide.

The most recent coolant change was 7yrs and 50k miles ago. Never had to add significant water in that time.

Why is my coolant now gold colored? Was it always gold colored? I can't remember. Does age cause the dye to drop out of solution and lose the green color?? Or was the wrong coolant installed last time??

My local dealer stocks the current green VC-5 and the gold VC-7. Not sure which one to use for my upcoming drain/fill! I think it's bad juju to mix.

Did the second generation SOHC ever get the gold coolant? I plan to stick with some type of Ford fluid - I bought both types to be ready...

BK

 

[BK_89iX]

Poked around some more....found this official usage chart....looks like the "gold" didn't start until 2002:

http://fcsdchemicalsandlubricants.com/main/quickref/scuc.pdf

BK

 

[gijoecam]

It mixes with rust from the ferrous parts in the system as it ages and loses its corrosion inhibitors. Time to change it again.

 

[Electrohacker]

the new trend i that prestone ready mix stuff (yellow colored)

I still prefer PEAK full concentrate and mix my own (green colored)

you should flush the system every 3 years or so

 

[BK_89iX]

Yep, I know it's past the time to change it. Vehicle was unused for a while and fell behind on some of the scheduled maintenance. Playing catch-up now after deciding to keep it. Owner Guide specifies 48-months/50k miles on the coolant. I will do it every two years going forward, just like my other vehicles.

Still not sure about the color thing and what's in there right now. I think the best course is to perform a thorough flush and install the specified VC-5 green. As mentioned I'm sticking with fluid sourced from the dealer.

BK

 

[BK_89iX]

SOHC cooling system capacity?

Performed a very thorough flush of the cooling system with water. The color of the fluid in the overflow tank was very ambiguous, but the the liquid coming out of the drain tube that I connected to the radiator petcock was green and not yellow. I installed fresh Ford green VC-5 with distilled water - the specified material for my motor and the closest match to what was in there.

My owner manual spcecifies 7.8qt capacity, but it's not exactly clear what motor that applies to. Each of the three times I drained the system I got about 2.5 gallons out, including fluid from the overflow tank. After the usual overnight cooldown I need to top up a bit more. Not sure if I should add straight VC-5 coolant (would need to buy another gallon) or distilled water. Anyone know the real capacity for the V6 SOHC cooling system? I have exactly one gallone of VC-5 in there now and want to maintain a 40-50% coolant proportion.

BK

 

[gijoecam]

Measure your concentration using a float hygrometer. Adjust based on those results.

 

[BK_89iX]

Measure your concentration using a float hygrometer. Adjust based on those results.

Fair enough - that is THE way take the guess work out of it and know for sure!

BK