OH No ! Not more coolant info

[haydn callow]

There is a bit in the article below that explains why the Low Coolant Alarms when fitted at the same time as a load of new coolant start to play up....then whenthe Sensor Screw is cleaned a few weeks later all is well. Some new coolants "coat" the inside of the system (and the sensor screw.




If you’re looking for a ‘one size fits all’ strategy, your best bet is to stick with tube socks and steer clear of modern cooling systems. These systems won’t tolerate substitution of inappropriate or—worse—incompatible coolants.

In all the years we’ve been reporting on cooling systems, we’ve never seen the antifreeze situation more confusing. While the dye colors being used seem to have exhausted the rainbow, we hope most technicians have learned that the color of the antifreeze dye has nothing to do with the corrosion protection formula for the ethylene glycol-based fluid. At each individual car manufacturer, the procedure is to change the dye color of its assembly line coolant when the formula is changed, although Honda changed from dark green to dark blue while retaining the same formula.

The what-to-use issue became even cloudier this year as Ford began a multiyear changeover to a single worldwide antifreeze. It had a choice of three formulas that it’s currently using on domestic products. We’ll spare you the suspense: Ford is moving to the orange-red OAT (organic acid technology) antifreeze/coolant it uses in all of its European vehicles, and that tells you that even more Ford of Europe engineering is coming here. At present, we have the Transit Connect panel van imported from Turkey, and the Fiesta economy car, engineered in Europe, that’s being built for the North American market in a plant in Mexico.

Ford’s coolant reservoir labeling adds to the confusion. The label on the 3.5/3.7 V6s on the Lincoln MKT says “no orange,” even though Ford is in the process of converting to it. It’s not the current factory fill, and Ford doesn’t want the present OE protection formula adversely affected.

The new F-Series heavy-duty models have two new U.S.-built V8 engines—a 6.7L diesel and a 6.2L gasoline version. The new Mustang also has a new gasoline V8—5.0L, to go with the 3.5 V6. These new engines are factory-filled with the OAT coolant. And in case you’re wondering, that OAT is a DexCool clone—basically what General Motors has been using since 1996.

One worldwide coolant makes a lot of logistical sense, and even saves Ford some money. But using an OAT coolant does require a lot of specific engineering, as GM learned, so Ford is going slow. The company actually will phase out engines (such as the 4.6 and 5.4 V8s) rather than attempt to convert them from the yellow dye hybrid OAT (H-OAT) it has been using in most of its domestic products since 2002.

This go-slow approach should tell you that, beyond any doubt, you shouldn’t use an OAT coolant in any Ford product for which it was not specifically engineered. That’s not our statement (although we believe it); it’s from Ford, and for good reasons. Also, don’t use it where it may eventually go—for example, in the 3.5/3.7 V6s.

Advertising claims by some antifreeze producers to the contrary notwithstanding, these OATs—certainly DexCool—are not universal coolants. You should use them only in General Motors products, VW/Audi through the 2009 model year and Ford vehicles where the reservoir label says so. After all, if it didn’t matter, Ford would put an OAT antifreeze in all of its engines, including the 4.6 and 5.4L V8s. Obviously, it does matter. Furthermore, you should use an antifreeze that isn’t just compatible with what’s in the system, but one that has a similar inhibitor formula (mimics it), so the inhibitors in there are boosted, rather than diluted by something else.

As a result, the only recommendations we cite are in that category. For example, we wouldn’t advise an Asian formula that didn’t contain phosphate, or in most European cars (OAT-fills excepted) an antifreeze that didn’t contain silicates. Nor would we consider a conventional American green formula with both silicates and phosphates for those vehicles whose formulas contain silicates or phosphates.

Here’s the background on these recommendations and the issues behind them:

Silicated H-OAT antifreeze uses the popular inorganic inhibitor silicate, which not only protects aluminum very well, but also provides fast protection. That’s particularly important in case a water pump cavitates (imploding coolant bubbles that pockmark the chamber). When left unprotected, the pockmarks corrode, causing the pump to fail). The organic acid is called benzoate, and its effectiveness in combination with silicates is well established. The antifreeze inhibitor package also contains a copper/ brass inhibitor, either BZT (benzotriazole) or TTZ (tolyltriazole), to protect any small copper parts used and any service parts that may be installed later.

Ford has used this silicated H-OAT formula since the 2002 model year, Mercedes even longer (over 20 years)—it’s the yellow OE coolant, the aftermarket equivalent being Zerex G-05 or Havoline Custom Made. Chrysler also uses it, but the OE stuff has orange dye, so don’t confuse it with DexCool. This silicated H-OAT antifreeze also contains nitrite, which enables it to protect diesels against cylinder liner vibration-caused pitting. That’s one thing Mercedes likes about it, as does Chrysler for its Cummins diesel engines.

The third coolant also is an H-OAT, but this one—preferred by Asian carmakers—uses phosphates instead of silicates. Phosphates quickly reprotect a cavitation-pockmarked pump, plus the Asian makers use BZT or TTZ to protect copper/brass. In Ford and Mazda products, particularly the 3.5/3.7L V6s, the dye is deep green. Other Asian makers may have pink dye (Toyota/Lexus) or blue (Honda). The organic acid is sebacate, as Asian makers refuse to use the chemical ingredient ethyl hexanoate (2-EHA), primarily because it affects gasket materials. They also dislike silicates because in some tests they run, silicates form a gel that could plug passages. Gel formation and plugging is not particularly a real-world issue with the low silicate content in the silicated H-OAT antifreeze. In fact, the only cases we’ve seen where there was real plugging (as opposed to relatively minor deposits) were with higher silicate content in older antifreeze formulas. And even that gel-plugging was rarely seen, unless a vehicle had been sitting unused, in which case the silicates may have dropped out. Silicate dropout, however, also may occur if the antifreeze has been sitting on the shelf for a few years or more.

For overall protection, though, silicates beat phosphates. But to maintain the original Asian antifreeze protection, you want the phosphated H-OAT. There’s finally an aftermarket formula you can buy—Zerex Asian Long Life. The dye color is a shade of pink, but it matches up well chemically with all the Asian vehicle antifreezes, regardless of color. In fact, it’s the same formula that’s used by Hyundai, despite the different dye color (Hyundai’s is blue-green).

No antifreeze is perfect, and that certainly includes an OAT. The OAT contains 2-EHA, and usually in combination with sebacate. So the formula is these two organic acids, plus TTZ for copper/brass.

OAT antifreezes last a long time, but also take a long time—about 5000 miles—to establish protection for cooling system passages. And the slow action means they can’t quickly protect water pumps that are pockmarked by cavitation. So the pump and cooling system must be engineered to minimize cavitation, which is primarily a high-load issue. The chemical 2-EHA causes leaks in silicone rubber gaskets and Nylon 66 gasket carriers, so they must be avoided.

Because OAT antifreezes protect best when the system is absolutely full, which means the coolant is in contact with the walls of the system, maintaining a full fill becomes another issue. This is particularly important with cast-iron engine blocks, where a low level causes rust “blushing” on cooling system walls, a pickup of the rust from coolant flow and deposits in the radiator (see the photo on page 26).

Although Ford cars have all-aluminum engines, the Super-Duty F-Series truck has the new 6.2L gasoline V8 and 6.7L diesel V8, both with cast-iron blocks. Low coolant level also can affect aluminum heads, so always check the coolant level whenever a vehicle is in for service. If it has a pressurized reservoir, you can check that level easily. If the pressure cap is on the radiator, remove it to make sure the system is topped up; a high level in an atmospheric reservoir doesn’t guarantee the system is full.

Ford designed all of its European engines to minimize water pump cavitation, and where possible, it did the same on its U.S. engines (the 3.5 and 3.7L V6s and the I-4s), so they could live with the OAT antifreeze. No such luck with the 4.6/5.4L V8s, which, along with the gasket issue, is why they continue to have the silicated H-OAT until those engines are history.

Ford has been particularly sensitive to guarding against low coolant level, which was responsible for the rust “blush” plugging of radiators on some GM cast-iron V6 and V8 engines.

Most Ford engines, not just the cast-iron types, have cylinder head temperature sensors, and in some cases on engines already equipped with coolant temperature sensors and even low-coolant-level sensors in the reservoirs. Ford in particular uses the head sensors, for a low coolant strategy that puts the engine into a limp-along mode to protect against warping or worse.

Ford also was alert to the cylinder liner pitting issue. You can’t use nitrite in the OAT formulation—it’s a bad mixture. So the new 6.7L diesel was engineered to minimize piston slap. The small amount of protection an OAT coolant provides will be enough to prevent liner pitting, Ford says.

An important service lesson, in addition to continuing with whatever is the Ford OE antifreeze: Service parts could be an issue, particularly water pumps and those gaskets that seal coolant passages. Many head gaskets, for example, have silicone sealing rings for the coolant flow holes, and you wouldn’t want to use them for engines with an OAT coolant. Ford has all-metal gaskets for the OAT-equipped engines, Motor was told.

Aftermarket suppliers have been alerted to the water pump (design for minimum cavitation) and gasket issues, and the reputable ones surely will engineer appropriate new parts. However, you just might get an aftermarket gasket that was made for the 3.5/3.7 V6s before the coolant change, and if it were made with silicone rubber (or with Nylon 66), it might create a service issue when Ford changes the V6 to an OAT coolant. So a coolant-passage-sealing gasket for a Ford engine that has been changed over to an OAT antifreeze should be an object of caution, if the gasket has been sitting on a parts jobber’s shelf for years.

Ford is not pushing the service life envelope very much with the OAT coolant. It’s 6 years/100,000 miles for the factory fill and every 3 years/50,000 miles thereafter. On the new diesel it’s 6/105 for the factory fill in “normal” service and just 2400 hours/60,000 miles in “severe” service (lots of idling, heavy loads—the usual truck stuff). The diesel service interval thereafter is just 3 years/45,000 miles in “normal” service, but 1800 hours/45,000 miles in “severe” service.

A likely reason for the shorter service interval after the factory fill is replaced is that Ford uses deionized water for the 50/50 mix on the assembly line, and although it would like to see the aftermarket do the same, it obviously isn’t taking bets that will happen. Because an OAT coolant takes about 5000 miles to establish protection, using pure water for the factory-fill mixture obviously helps protect the system until the mixture has done its job.

But we also would note that antifreeze lasts longer if the water with which it’s mixed is free of minerals and other content. You also can use distilled water for service, if that’s easier to get. A gallon jug is maybe a buck or so, and we think it’s a great investment for any well-maintained cooling system. It’s also a plus to which you can point proudly when you hand a customer the bill and explain why your shop does a better job

[mikexgough]

The Ford Motorcraft coolant they use now is the same as Post 2006 Mazda FL22....

Which in europe is the same chemistry as G12++ types which now is mainly Purple coloured. .... ..or Red (dependent on manufacturer of course) and used widely by VW group...Peugeot Citroen...etc..from new

The key thing with coolant is as we know...... read the label and know what your feeding your system.... and as we have already covered I shall not say anymore..... Whatever coolant you use....your call...just don't mix types....
I personally stand in the Red OAT G12+ camp as many of you know as it is the closest chemistry to Factory coolant as there is, plus with the 130C boiling point at 50% ratio.....but at the end of the day....your call..yer pays yer money and all that

I have seen a neigbour using that Yellow "Prestone" brand (pre mixed) as a top up for his car at the weekend..... It claims to be universal and mix with all coolants.... - lets just say.....he has not experienced any issues yet with the 300 ml he added and the yellow coolant mixed and changed to the Green he had in.....instant mixed, I had expected it to have "laid" on top until the system ran but it just mixed straight away... the future?....or at least perhaps a "get out of jail card"?

[mikeonb4c]

Could I make a suggestion guys:

When writing a long dissertation (on anything), put a brief summary + recommended actions at the top. I will most likely do what is recommended in this summary, as long as I know the author is respectable. But lengthy stuff is likely only to confuse (and to hide the important bits from) a hasty reader like me (and I can't be the only one!).

For what it's worth, I use old fashioned ethylene glycol a/f, and my LCA hasn't given any trouble whatsoever in 4 years of operation and 2 coolant changes.

[haydn callow]

Carn't agree with that Mike.......there are a lot of relevent points in that article and I would prefer to pass on the whole message for peeps to evaluate.....e.g. it is not generally known that cavitation around the water pump of many engines is such a problem.....take that a step further to what has been suggested on here about cleaning up the thermostat housing when changing the stat....this will remove this protective coat.....perhaps cleaning it is a bad idea....
Just my views...

[mikeonb4c]

Carn't agree with that Mike.......there are a lot of relevent points in that article and I would prefer to pass on the whole message for peeps to evaluate.....e.g. it is not generally known that cavitation around the water pump of many engines is such a problem.....take that a step further to what has been suggested on here about cleaning up the thermostat housing when changing the stat....this will remove this protective coat.....perhaps cleaning it is a bad idea....
Just my views...

Put a summary etc. at the top, then put the full bumf for those wanting in-depth knowledge. Its good practice for serious professional report writers. It will probably make more readers want ot read on anyway

[mikexgough]

Could I make a suggestion guys:

When writing a long dissertation (on anything), put a brief summary + recommended actions at the top. I will most likely do what is recommended in this summary, as long as I know the author is respectable. But lengthy stuff is likely only to confuse (and to hide the important bits from) a hasty reader like me (and I can't be the only one!).

For what it's worth, I use old fashioned ethylene glycol a/f, and my LCA hasn't given any trouble whatsoever in 4 years of operation and 2 coolant changes.

I didn't go into Cavitation etc. with my comment, as it can lead to more confusion, but I get what your saying Mike.
As for Cavitation, the Bongo cooling system is of such a design that water punp cavitation is kept in check and reasonably low and as some know I have done some work on the Bongo system type and even compiled a fact sheet type explanation to go with it. I have yet to do a simple version of that but I have hit "the wall" as I am getting to the point where it can be too simple or too complicated.As you say Mike, Hasty readers like things to the point, hence my issue with simplification of my Cooling system evidence,factsheet and patent.

[mikeonb4c]

Could I make a suggestion guys:

When writing a long dissertation (on anything), put a brief summary + recommended actions at the top. I will most likely do what is recommended in this summary, as long as I know the author is respectable. But lengthy stuff is likely only to confuse (and to hide the important bits from) a hasty reader like me (and I can't be the only one!).

For what it's worth, I use old fashioned ethylene glycol a/f, and my LCA hasn't given any trouble whatsoever in 4 years of operation and 2 coolant changes.

I didn't go into Cavitation etc. with my comment, as it can lead to more confusion, but I get what your saying Mike.
As for Cavitation, the Bongo cooling system is of such a design that water punp cavitation is kept in check and reasonably low and as some know I have done some work on the Bongo system type and even compiled a fact sheet type explanation to go with it. I have yet to do a simple version of that but I have hit "the wall" as I am getting to the point where it can be too simple or too complicated.As you say Mike, Hasty readers like things to the point, hence my issue with simplification of my Cooling system evidence,factsheet and patent.

I agree Mike, plus many readers aren't technically inclined and just want the 'beef'. You get taught this kind of thing when writing news releases too: you have 50 words to grab the journalists/readers interest and persuade them to read on.

[haydn callow]

Whatever !!!!

There is obviouslt a lot of interest in this subject as the length of the last "coolant" topic will testify.

There is also the point that, that article was written by a person who knows a little bit about coolants and cooling systems.......I would not consider myself to be knowledgable enough to edit out any of his work.....

[munroman]

I tend to agree with Haydn, for technical articles it can be impossible to write a concise precis without losing vital information, and these should really be written by an expert in the subject.

I think that not many people on here could be called true 'experts' in such an arcane subject, so it is better to leave the article as originally written.

One forum I use has the protocol of putting 'Warning - Verbose!' before lengthy posts, that way people are warned off getting lured into a lengthy read.

This would at least give people the warning that they need a cup of coffee before they start reading!

[mikexgough]

I tend to agree with Haydn, for technical articles it can be impossible to write a concise precis without losing vital information, and these should really be written by an expert in the subject.

I think that not many people on here could be called true 'experts' in such an arcane subject, so it is better to leave the article as originally written.

One forum I use has the protocol of putting 'Warning - Verbose!' before lengthy posts, that way people are warned off getting lured into a lengthy read.

This would at least give people the warning that they need a cup of coffee before they start reading!

I certainly would not consider myself to be an expert, however I have built up an enourmous amount of knowledge and information over the last 18 months since my radiator split.... initally to quosh any myths and legends about the Bongo cooling system but also to equip me with knowledge of how the system works.
Consequently, a how it works thread started about the flow and has progressed since...... in the mean time, I have been working in the background....to find out loads of things about the cooling system, right back to basics of when this kind of system was designed etc.
As well as how it works on a Bongo and also why the WL-T engine is prone to head gasket failure.....and it has nothing to do with the Bongo cooling system pipework at all.
The key is not in the patent/design but to understand how th system works in basic terms, the rest is to get it linked to how it works on a Bongo.....and all the qustions....answer themselves..... .

[mikeonb4c]

I tend to agree with Haydn, for technical articles it can be impossible to write a concise precis without losing vital information, and these should really be written by an expert in the subject.

I think that not many people on here could be called true 'experts' in such an arcane subject, so it is better to leave the article as originally written.

One forum I use has the protocol of putting 'Warning - Verbose!' before lengthy posts, that way people are warned off getting lured into a lengthy read.

This would at least give people the warning that they need a cup of coffee before they start reading!

(Good) technical articles start with a summary THEN go on to write the full report. Think about it. Everybody from BMJ, 'New Scientist' to 'Which' and just about anyone professional in between that writes reports uses 'at a glance' techiniques like this. Basic stuff.

[francophile1947]

(Good) technical articles start with a summary THEN go on to write the full report. Think about it. Everybody from BMJ, 'New Scientist' to 'Which' and just about anyone professional in between that writes reports uses 'at a glance' techiniques like this. Basic stuff.

But, as Haydn says, he didn't write the article and doesn't feel qualified enough to edit it - I think you're talking yourself into a job Mike

[mikeonb4c]

(Good) technical articles start with a summary THEN go on to write the full report. Think about it. Everybody from BMJ, 'New Scientist' to 'Which' and just about anyone professional in between that writes reports uses 'at a glance' techiniques like this. Basic stuff.

But, as Haydn says, he didn't write the article and doesn't feel qualified enough to edit it - I think you're talking yourself into a job Mike

[haydn callow]

It would be a interesting exercise to see how it could be done without missing relevent points....as already pointed out ...it is a tecnical article not a short story....

[haydn callow]

and anyway....who cares ??? it's there if anyone wants to read it.....if it's to much of a task then "click" on to somthing else.......there must be simpler topics to read