Does anyone have an opinion on whether the Ford SCA and the NAPA SCA can be mixed? I have the NAPA SCA in my truck now, but need to increase the levels. I have a bottle of the Ford SCA on-hand. The Ford bottle doesn't have any warnings on it about mixing with other products. Not sure about the NAPA stuff.

 

No responses on this, so I went out and did some reading to get up to speed. Here's what I found out:

There seems to be two general categories of SCA's used.

For protection against cavitation corrosion, one uses a combination of nitrite and molybdate, and the other uses nitrite only.

Ford recommends the nitrite/molybdate version, and that's what the Motorcraft SCA is. This type is also used by Cummins in their engines.

The NAPA SCA is nitrite only. This version is used by Caterpillar in their engines.

It seems that the nitrite/molybdate version is a bit better, since the protective layer formed on the cylinder sleeve is more durable, but both versions are effective.

The bottom line (and the answer to my original question) is that the NAPA and Motorcraft SCA's should probably not be mixed if it can be avoided, although it would likely not cause any problems directly. The risk would be starting out with the nitrite-only version and using test strips that don't measure molybdate, then adding a nitrite/molybdate SCA and continuing to use the nitrite-only test strips. The molybdate level, if left unmonitored, could get out of tolerance (too high) and cause problems. Using test strips that measure nitrite and molybdate would prevent this, and they can be used with either version of SCA.

To keep it simple, stay with what you started with.

Any comments would be appreciated.

 

I'm wondering if I can flush out the green coolant and switch to the Ford gold. I have a '97.

 

i would be careful about switching coolant types due to the fact of the gaskets are known to be compaitble with the green coolant in the trucks that came with green. i havent seen anywhere where it has been confirmed that the gold is ok in the green coolant trucks. i just run the sca that the international dealer carrys.

 

If your engine is a pre 99-99.5 you'll have to keep running the Green Coolant w/ the SCA's. Int'l put out a bulletin a while back for the T444E (IH speak for "PSD") that stated the gaskets/seals in the older engines were not compatible w/ the newer Gold Coolants. If I can figure out how to post a *.pdf file I'll post it here. The bulletin lists @ which engine S/N & date they switched over the gaskets to work w/ either Green or Gold.

My 00 F250 came w/ Green but, my wife's 03 came w/ gold. That's what led me to talk to a local Navistar (IH) Dealer to find out what was up with the coolants.

Hope this Helps,
D

 

Can't figure out how to post the PDF. Look for Bulletin 299 (dyk299.pdf dated 7/17/00) in the did you know section of Navistar's website. Got an error when I tried to post the direct link.

This is what the dealer showed me.

D

 

Try this


http://www.internationaldelivers.com...pdf/dyk299.pdf