Bare with me. I did a quick glance at a post of coolant choices. I don't want to add additives for cavitation. Is rotella elc ok to use? Previous owner replaced the radiator and used coolant says safe for all makes and models. What other issues do I need to know about? 245k miles and I want to keep it running also this is my first diesel truck.

 

94 f350 4x4 crew cab 7.3 idi (no turbo)

 

I don't know what Rotella ELC is but you DO need SCA for your diesel.

 

 

I like Zerex HD ELC.
SCAs are only for basic green coolant, and must be used for that.
Pretty sure SCAs will screw up an ELC coolant, so for an ELC, you want one designed for diesels. ELCs are designed to /not/ need any additives for the life of the coolant.

 

I am not a chemist and don't want to open a lengthy scientific discussion but I know that SCAs are sacrificial elements.
I'd recommend to read the following document: https://www.cumminsfiltration.com/si...mpressed_0.pdf and pay specific attention for the first paragraph on page 2.

 

The point is that with an OAT/ELC coolant, basically enough 'buffering' capacity is built in for the life of the coolant, so 'topping up' isn't needed.
If you look at the "ES CompleatTM OAT", you'll notice it has a service life of 1,000,000 miles - basically the life of the motor.

Fleetguard is hedging their bets by saying that you *should* use a test-strip on *everything* once a year.

Zerex's is less conditional - they specify 3 years, 300,000 miles before testing or replacement is needed.
Valvoline? ZEREX? Extended Life Antifreeze / Coolant : Product Catalog - Valvoline®
Effectively, you don't need to check it - just use it and replace it after 3 years, or add an additive pack and keep it for another 3.

Anything that is /not/ an OAT/ELC coolant requires more frequent "top-ups", because the buffering components must be kept at a specific level - too much and it'll corrode things(copper I think?).

 

Yes I did see that. Basically all 3 except for conventional one have a service life of 1,000,000 miles. But that's for coolant itself, not SCA. I would still test it once a year.
The thing is that many people don't think of SCA being a sacrificial elements and take ELC coolant as a fool proof not needed to be tested. Most newer HD diesels have factory installed coolant filters so they don't have to worry about testing if use precharged filters. Not that many people with our old IDIs have them including myself so we need to be more careful.

 

Um... Look closer.
Only #1(red) is an OAT coolant.
Remember, the OAT/HOAT designation on ELC coolants(like Zerex HD ELC) *is* the type of corrosion inhibitor it uses.
The other 3 require some level of "SCA" additive, on top of other specific formulations for different things.

That all being said:
https://www.cumminsfiltration.com/si..._TB03-05-2.pdf
This seems to clear up a lot of things.


Even so, I stand by my original statement:
With a conventional coolant(non-OAT), you need SCAs, and test strips, and need to test it every 6 months or so.
With a OAT/HOAT ELC coolant(like Zerex HD ELC), you don't need to test it for 3 years.
(at which point you can test it, add additives, or simply flush the system).

 

Well, I need to admit that I was wrong, OAT, HOAT, NOAT coolants don't need SCA additives. Some people say that these can't be used on older engines but I would need yet to hear of any failure because of that.
Oh, yes I have seen that Fleetguard Tech Bulletin you referred to. This bulletin in particular can be useful for people who are afraid of mixing different types/brands of coolant.
Two more documents can be useful for people researching on the topic:
Final Charge Global 1,000,000 miles warranty http://images.peakauto.com/Warranty%...%205-16-13.pdf
and their FAQ FAQ - Final Charge | PEAKhd.com
The confusion might be about what to call a conventional coolant though. Either the ones which meet older ASTM D4340 or anything that requires SCA...
For how long do you use OAT on your vehicle? I am changing my mind and will go with one of those on mine since there is still water in the system and truck is waiting for me to do the water pump before I fill the system with antifreeze. Maybe I will have time this weekend to play with her for a while.
Am I hijacking the post? Apologies to OP then.

 

Good information thanks guys

 

The above Fleetguard PDF mentions ONE ELC product that ALSO contains nitrite/moly SCA. FinalCharge (the Peak product) is similar; it's ELC anti-freeze with SCA _added_.

That does NOT imply that ELCs, in general, do not require SCA. The OAT/HOAT designation with ELCs is a reference to corrosion inhibition, NOT anti-cavitation. Corrosion protection is required in ALL liquid-cooled engines. Cavitation is a completely different physical/chemical process that is specific to compression-ignition (aka diesel) engines.

I still haven't seen an article that states that the chemical properties of ELCs in general also constitute protection from _cavitation_ (once again, completely unrelated to _corrosion_), and do not require anti-cavitation maintenance, either by the user through the res/rad cap or via a pre-charged filter.

 

Don't they call cavitation liner pitting?
They don't mention DCA compatibility for OAT, just say compatible with non chemical filters. Different story for the rest, DCA compatibility with liquid DCA or chemical filters. Both organic and inorganic are ELC. As I said before, the ELC designation is kind of confusing in regards to SCA maintenance.
I don't make any statements, just discussing the information provided by manufacturers.
There is a star for service life for each coolant listed by Fleetguard which means - (quote)

"*To maintain the protection provided by Fleetguard coolants, the proper level of inhibitor must be present.
This can usually be achieved by topping off the cooling system with premixed Fleetguard coolant.
The user is responsible for ensuring proper additive levels and coolant pH through the use of test strips
and the addition of additives or new coolant if necessary. The recommended test intervals are as follows:
OAT coolants – 300,000 miles, 6,000 hours or 1 year; Hybrid coolants – 150,000 miles, 4,000 hours or
1 year; Conventional coolants – Every oil drain interval or 1 year. The shortest of recommended hours, miles
or 1 year should be used as the test interval. The test interval is a precautionary recommendation intended
to prevent maintenance and engine problems from causing progressive, severe engine damage.*"

Not specified what protection they are talking about and not clear what to do with 1,000,000 miles OAT coolant after 300,000 miles.

Zerex has "Extended Life Extender" though...Sounds kind of funny to me.
All this marketing thing is very confusing.

 

When I was getting my 7.3 IDI back on the road I researched this a lot and also figured out that the cheapest way to do a coolant flush is to use the 100% undiluted Rotella ELC from Tractor Supply, and then mix it in with your own distilled water, which is about $1 a gallon at the the grocery store. The Rotella is precharged with all the SCA's you need for your motor. One bit of advice, buy a lot more distilled water than you think you will need and flush your engine several times, getting up to operating temp each time. When you drain the coolant/water out pull the water passage plugs on the bottom of the motor to help you get it all out. This engine holds a lot of coolant, and even after three flushes it will still be tinted green. You want to get all that green stuff out before you put the red ELC in. It took me several hours, and I disconnected my heater core and tee'ed the lines into each other to try to make it go quicker.

 

OK,

I've been reading all about coolants as confused as the next but now have my bearings. First, My 88 van has the red stuff in it from the PO. i thought I had to test it.

Here's what I found, ELC does not need testing, only SCA needs testing because the additive wears out. I'm going with MACROBB and staying with the ELC coolant here's why. They say many mechanics will test for SCA in RED ELC coolant, it tests low because ELC doesn't have SCA's in it and they add SCA when it doesn't need any. Thus, the system has to be flushed and reset with ELC because the SCA additive neutralizes the properties of the ELC and turns it into regular SCA coolant.

The only regular testing needed with ELC coolant is to check it's freezing point.

In another forum the Coolant experts explain this. The SCA coolant was designed to Coat the cylinder liner with nitrites to prevent cavitation. Those levels wear out quickly over time. Thus the nitrite levels need to be checked with test strips. The nitrites allow water to explode but minimize the impact or effect on the cylinder wall but that also is why the SCA wears out. This was the temporary fix until a new technology could be created thus entered the ELC coolant.

ELC contains carboxylate technology that prevents the water from cavitating in solution. This technology is through the whole mix of coolant thus no need for coating the cylinder liners. This technology prevents the high temperature air bubbles from forming in the water to begin with that causes the cavitation and cylinder wall damage. The midpoint life of this coolant is 300,000 miles. At which they say there should be testing to replenish the ELC properties. By that point, why not just flush the system and refill with new ELC coolant.

Now one other point they mention is the use of a blank coolant filter to keep the coolant clean of particle matter because of the long life coolant properties. My van doesn't have a coolant filter, and since it's already been converted to ELC Red, I'll be looking to install the coolant filter. I've seen some small solids floating when I tested the freeze point which was very low, overall it's very clean and clear red fluid. I see no coating buildup, radiator channels look clear. Plus the engine has run very cool.