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Mar 11, 2025 | 09:33 AM

BillyBob69

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From: Wheatland, Mo

Just another coolant thread

Say what you want but I have been lacking in maintaining my old 99 over the past couple years.
The old girl has been mostly retired to picking up an occasional load of hay, taking the tractor in for yearly maintenance and hauling the boat all of 1-1/2 miles to the lake during the warmer season.
It has never overheated in the 19 yrs I have owned it. Always held coolant in the degas bottle... until apparently for some time now.
Did an oil change 9THose I keep up with), and noticed the bottle was empty. Nothing on the shop floor, no drips or wet spots...then I saw green and white crust looking like something crawling out of the thermostat housing base.
So that needs to be replaced. And I have one already...not sure I recall why I bought one but...I have it.
Antifreeze. I vaguely recall using a green antifreeze and adding some additive, I just don’t remember what.
Not sure how long coolant has been low, honestly. So not sure how long I have driven it with an empty bottle. But the needle has never gotten further than about halfway between cold and half way. Heat works fine so there has to be some left in there.... right?
Thoughts on products?

Thanks all!

Mar 11, 2025 | 11:39 AM

Pikachu

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From: Amarillo, TEXAS!

Green with an SCA additive like Napakool is fine. Grab a 2 pack of test strips if they have them also.

Mar 11, 2025 | 11:55 AM

BillyBob69

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From: Wheatland, Mo

Quote:

Originally Posted by Pikachu

Green with an SCA additive like Napakool is fine. Grab a 2 pack of test strips if they have them also.

Thats what I was looking for. Napakool. That I do remember now.
THANK YOU!

Mar 11, 2025 | 03:49 PM

John in OkieLand

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From: Oologah, OK

Can you run ELC coolant in the 99s ?

that is what was in my '02 when I bought it,
replaced it with Rotella ELC when the water pump locked up.

Mar 11, 2025 | 06:07 PM

BillyBob69

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From: Wheatland, Mo

I have

Quote:

Originally Posted by John in OkieLand

Can you run ELC coolant in the 99s ?

That is what was in my '02 when I bought it,
replaced it with Rotella ELC when the water pump locked up.

Been doing that in my E99 since I replaced my water pump in 2009. Still in the same pump and have had ELC the whole time. Truck has never overheated.

Mar 11, 2025 | 06:50 PM

John in OkieLand

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From: Oologah, OK

I had assumed that ELC would work in just about anything, so it seems it will.

Mar 11, 2025 | 09:15 PM

Blue_Oval1

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Quote:

Originally Posted by John in OkieLand

I had assumed that ELC would work in just about anything, so it seems it will.

Supposedly the ELCs don't play nicely with the sealant used in the early 99 injector cups from the factory, late '99 and after as well as earlier engines with replaced cups are said to be fine with ELCs. Mine is an early '99 so it's low-silicate green and Ford VC8 SCA.