Flushing Yanmar 4JH2E Coolant

[a64pilot]

There has been a lot of problems with Dexcool, a lot of it I'm sure is due to it's incompatibility with other coolants. Just Google Dexcool problems.
It's the orange stuff, I wouldn't put Dexcool in anything although I've had cars that came with it and I had no problems, my wife's' CTS-V has it in it, I believe.

[jabaraco]

This is an old thread, but here goes:

The Yanmar recommended coolant, Texaco 2997 (now part #222997), is an NOAT, that is a Nitrited (not NitrAted) Organic Acid Technology. As far as I know, almost ALL of the these NOAT Extended Life Coolants (Shell Rotella ELC, Mobil NOAT ELC, Delo ELC, Final Charge NOAT) are made by Old World Industries a/k/a Peak Industries.

Here is a VERY comprehensive cross-reference chart:

http://www.steelcitylubricants.com/p...Chart_0413.pdf

Yanmar states it is important to use a NITRITED OAT formula to avoid "cavitation pitting" on the various aluminum parts in the engine. These are tiny bubbles caused by the cylinder walls that cause microscopic bubbles to form and collapse with thousands of PSI against the metal, hence the pitting.

I found Mobil Delvac NOAT, but it is EXACTLY the same as the others shown in the chart because they ALL come from the same vat...this is confirmed by Mobil and Old World.

They all state that the NOAT ELC is good for minimum of 600,000 miles or 12,000 hours (for heavy duty diesels such as trucks or earth-moving equipment), for what it's worth...

The official Yanmar bulletin recommending an ELC is attached...

Hope that helps.

michael

[jabaraco]

Sorry, here is the Yanmar Service Bulletin

http://scyr.org/stellablue/images/st...ar_Coolant.pdf

[sbrin]

Getting ready to change my coolant (Yanmar 3JH) as well and read the above with interest.

I did some reading on coolants and it seems that the new "OAT" coolants without the "N" are felt to be better than the NOAT coolants (seem to be a blue color). Longer lasting than the NOATs with fewer cavitation or additive needs.

Has anyone used the OAT coolants? Are these motors (Yanmar 3JH series) "wet" or "dry" sleeved motors?

Regards,

Steven

[jabaraco]

Hmmm. First I heard of a blue coolant.

Anybody else can chime in, but I think that the 3JH and 4JH use wet liners...

Here is an interesting SAE article about Chrysler being the last of the Big Three to switch to an ELC.

Chrysler switches to OAT antifreeze for longer service interval - SAE International

I would check with Yanmar or one of their distributors(I have not). As far as I know, their 2002 recommendation to use a NOAT coolant still stands...the primary reason is the 100 of hours or so it takes a new engine to form a coating with pure OAT formulations. Maybe if the engine is past that (almost all used boats are) then maybe it doesn't make a difference...but again, I would check with Yanmar or perhaps Mack Boring in the East Coast who seems extremely knowledgable about all things Yanmar.

For what it's worth, I'm going to replace the Dexcool OAT in my 4JH2E with a Mobil Delvac NOAT in the next few weeks...

[mashenden]

Originally Posted by jabaraco

This is an old thread, but here goes:

The Yanmar recommended coolant, Texaco 2997 (now part #222997), is an NOAT, that is a Nitrited (not NitrAted) Organic Acid Technology. As far as I know, almost ALL of the these NOAT Extended Life Coolants (Shell Rotella ELC, Mobil NOAT ELC, Delo ELC, Final Charge NOAT) are made by Old World Industries a/k/a Peak Industries.

Here is a VERY comprehensive cross-reference chart:

Yanmar states it is important to use a NITRITED OAT formula to avoid "cavitation pitting" on the various aluminum parts in the engine. These are tiny bubbles caused by the cylinder walls that cause microscopic bubbles to form and collapse with thousands of PSI against the metal, hence the pitting.

I found Mobil Delvac NOAT, but it is EXACTLY the same as the others shown in the chart because they ALL come from the same vat...this is confirmed by Mobil and Old World.

They all state that the NOAT ELC is good for minimum of 600,000 miles or 12,000 hours (for heavy duty diesels such as trucks or earth-moving equipment), for what it's worth...

The official Yanmar bulletin recommending an ELC is attached...

http://scyr.org/stellablue/images/st...ar_Coolant.pdf

Hope that helps.

michael

Thank you for the info - Very helpful. The Service Manual and Operations Manual for my Yanmar 3JH3 is so vague about the type, its downright annoying. I spent WAY too much time research what type of antifreeze to put in it. Your info definitely helped. I ended up going with Mobil NOAT ELC because it was available at a local truck stop.

Interestingly, on a parallel note, I am finding that these engines do not have sacrificial anodes zincs. Seems like a strange place to cut costs, but I suppose theoretically they are not needed - Time will tell....

[jabaraco]

Thanks! I think that the "no anode" design is, in fact, by design. I read somewhere that Yanmar designed the Salt Water Cooling system to have no dissimilar metals, hence, no sacrificial anodes. Don't know if that's true, but would love to hear from a Yanmar 4JH2/3/4 expert to confirm or deny...

Michael

[deander]

Hi Folks,
Thanks everyone for you contributions. I've gotten no where with Yanmar concerning my coolant issue.

I've been doing a lot of reading to figure out how to approach my issue. I have a 2GM20F that needs a flush and fresh coolant. I found a pasty/slimy deposit on the thermostat and inside of all hoses. Seems previous owners didn't manage coolant well. So, its time for a flush and new coolant.
For the flush, the recommendation is de-ionized or non-mineral bearing water. I plan to do at least two flushes. I was thinking of adding some cleaning vinegar but considering the risk of an acidic substance & considering that coolants are typically pH 8-9 that might not be a good idea. Also, after immersing the thermostat in that stuff for a couple days, very little pasty/slimy stuff came off so what's the point of using it?

Practical sailor had good results with Peak's Final Charge NOAT which prevents pitting on the wet cylinder sleeves. However, the old Yanmar bulletins only mention Havoline and Texaco products. I checked pH, silicone (should be 0), carboxylate and molybdate content and found Texaco and Final Charge to be the same. Final Charge also claims high temperature protection for aluminum. Here's the link to the product:
http://oilmart.com/data/products/pds...rge%20NOAT.pdf
So....for an ELC NOAT coolant, from what I read, Peak's Final Charge seems a good alternative to the Texaco products.

[earnric]

Originally Posted by jabaraco

This is an old thread, but here goes:

The Yanmar recommended coolant, Texaco 2997 (now part #222997), is an NOAT, that is a Nitrited (not NitrAted) Organic Acid Technology. As far as I know, almost ALL of the these NOAT Extended Life Coolants (Shell Rotella ELC, Mobil NOAT ELC, Delo ELC, Final Charge NOAT) are made by Old World Industries a/k/a Peak Industries.

Here is a VERY comprehensive cross-reference chart:

http://www.steelcitylubricants.com/p...Chart_0413.pdf

Yanmar states it is important to use a NITRITED OAT formula to avoid "cavitation pitting" on the various aluminum parts in the engine. These are tiny bubbles caused by the cylinder walls that cause microscopic bubbles to form and collapse with thousands of PSI against the metal, hence the pitting.

I found Mobil Delvac NOAT, but it is EXACTLY the same as the others shown in the chart because they ALL come from the same vat...this is confirmed by Mobil and Old World.

They all state that the NOAT ELC is good for minimum of 600,000 miles or 12,000 hours (for heavy duty diesels such as trucks or earth-moving equipment), for what it's worth...

The official Yanmar bulletin recommending an ELC is attached...

Hope that helps.

michael

I've been researching this and I think Yanmar now want you to NOT use a nitrited coolant since it causes problems with aluminum parts.

Can someone confirm that?

[Ocean Sky]

Originally Posted by earnric

I've been researching this and I think Yanmar now want you to NOT use a nitrited coolant since it causes problems with aluminum parts.

Can someone confirm that?

My coolant was changed by the service agent around 4 years ago 2018 , it is green.Is this likely NOAT?

The Texaco one mentioned in the 2002 bulleting is NOAT green?

I also read somewhere that Yanmar now recommend Red coolant,Is this likely a recent OAT formula?

I agree its all a bit confusing ...I will try contacting the service agent again and hopefully report back...

[RocketScott]

For flushing the system I'd recommend Star brite:

Descaling Motor Flush

Pick up a small water fountain pump from harbor freight and us that to circulate it through the engine. I assumed running star brite through it would eventually kill the pump, but it's flushed three engines and still works fine

[earnric]

Originally Posted by Ocean Sky

My coolant was changed by the service agent around 4 years ago 2018 , it is green.Is this likely NOAT?

The Texaco one mentioned in the 2002 bulleting is NOAT green?

I also read somewhere that Yanmar now recommend Red coolant,Is this likely a recent OAT formula?

I agree its all a bit confusing ...I will try contacting the service agent again and hopefully report back...

I do NOT think you should use the green. My mechanic was adamant. The Yanmar coolant (OEM brand) is red... I can't remember about the OAT vs NOAT. I have to go look at the bottle!

[earnric]

Originally Posted by RocketScott

For flushing the system I'd recommend Star brite:

Descaling Motor Flush

Pick up a small water fountain pump from harbor freight and us that to circulate it through the engine. I assumed running star brite through it would eventually kill the pump, but it's flushed three engines and still works fine

I did the same thing: home depot for the water pump.