coolant / ford 7.3 ( wet liner? )

[Bill_C]

Note for clarification: the Powerstroke 7.3 liter engines are NOT the same block as the earlier 6.9/7.3 IDI engines. Many people think all 7.3's are the same block, they are not.

The earlier IDI engines did have cavitation and pinhole issues. These were essentially eliminated with the newer Powerstroke 7.3 engines. As noted earlier, the Powerstrokes are parent bore, not wetted liner.

If the 7.3 is '95 model year or later, it is a Powerstroke. The '94 model years are confusing; Ford offered the 7.3 IDI normally aspirated, the 7.3 IDI turbo, and then in late 94 they introduced the 7.3 DI Powerstroke.

The coolant issue is often debated on the Powerstroke forums. I personally use Fleetcharge, pre-charged with the SCA, in my 94 Powerstroke.

Oh, and by the way, International made ALL of these engines. It's only recently that Ford switched to "their" motor.

 

[fieldserviceengineer]

From some posts it would appear that there is the belief that if the cylinder block design uses replaceable liners then those engines are the only models that require the use of a pitting (cavitation) protection chemical. While the Ford (International) engine is a parent bore block (cast in bores) it, too, requires the use of supplemental coolant additives as addressed by Ford in their O&M manual. Even the newest Ford diesels which have the factory-fill coolant, Motorcraft Premium Gold (Zerex G-05 antifreeze) is also a coolant that contains anti-cavitation additives only different from the Ford VC8 supplemental additive. To answer the post that the coolant choices by the OEMs are confusing, I would agree as now the pursuit of all phases of the market by these OEM companies has now encompassed "only our coolant, only our filters" mentality. So, if you are concerned about what to use in your Ford or International diesel, use Ford's recommendations. Use Intenational's recommendations. You cannot go wrong. But if are looking for one coolant and additive package that can be used in all your diesel applications then you have to do some studying to determine what are the coolant maintenance requirements for all these units and what are the common specifications. Dig deep enough and you may find that the underlying industry specification is ASTM D6210. Any coolant that can meet that specification will provide satisfactory engine cooling system protection when used and maintained properly. There is an earlier spec that was aimed at the trucking industry, TMC RP329. Both these specs are nearly identical when you dig into them.

Here they are in a nutshell:

* Both call for the use of a minimum of 1200 PPM of nitrite if the additive package uses only sodium nitrite as the pitting protection
* Both have an alternative additive spec that calls for a minimum of 780 PPM of a combination of nitrite and molybdate (sodium molybdate) but requiring a minimum nitrite concentration of 200 PPM nitrite and the balance can be molybdate
* Neither has a specification on the use of phosphate as a buffer agent as some Detroit Diesel service people will contend

The above are for premixed coolants, not concentrates. You can test a coolant with test strips that are available from Fleetguard, Baldwin, Donaldson, Fram, Wix (Napa). I do know that the all except the Wix (not sure about them) can measure both nitrite and molybdate and give results in PPM or in units per gallon as a measure of protection. The John Deere test strips have a different reference card and the numbers on that refer to how much liquid additive you need to add to get back to John Deere's recommendation for their engines. So, I would steer clear of the JD strips as they do not represent necessarily the requirements of other engines. Some test strips can measure only the nitrite level and ignore the molybdate level. Strips from Penray and Detroit Diesel measure nitrite only. No problem unless you have a coolant that has both additives such as the earlier Ford coolants treated with Ford VC8 (FW15, FW16). Strips that can measure both nitrite and molybdate can be used to test coolants that are nitrite-only.

Some coolants now coming onto the market no longer use any nitrite and little or no molybdate. While these products are OAT (organic acid technology) they do present a problem for you in your maintenance as there is no way to test them with present test strip technologies. I would keep away from those if you have a choice in coolant selection.

John Deere Cool Gard I was a hybrid coolant meaning that its inhibitor technology was composed of conventional cavitation protection (nitrite and molybdate for them) combined with an organic acid (benzoic) plus a buffer (antacid additive). Cool Gard II is now a hybrid "nitrite-free" coolant. At present, testing of John Deere Cool Gard II will only show a small amount of molybdate but since there is no nitrite. Test strips available now would treat that coolant as having no precharge and give maintenance instructions to add nitrite-containing liquid additives or coolant filters. As far as JD is concerned that would not be the outcome they want for that coolant. But adding conventional SCA to such coolants will not harm them nor cause any engine problems.