Non Yanmar coolant ok?

[LooseGoose]

diesel engines require diesel rated coolant.
Find your leak, fix it, top up with water just for the trip,

Then flush and fill with the recommended type and mixture. Use distilled water.

[CarlF]

While I am no expert I don't think I've ever used the Yanmar brand coolant in my Yanmar 4JH4's. My manual specifies Texaco or Havoline. They don't even mention Yanmar coolant.

The boat builder used Texaco and put some spare jugs onboard.

While there may be disagreements on color, I'm quite sure that "not green" is important - at least in the 4JH4's. You want a name brand Extended Life or Long Life coolant.

In any case, get the premixed so you don't have to worry about finding deionized water.

[sailorchic34]

Originally Posted by LooseGoose

diesel engines require diesel rated coolant.

Really it depends on if the engine uses wet sleeves or not. I believe that most newer smaller Yanmar's (3GM30F) onward at least for the smaller 3 and 4 cylinder types, use a dry sleeve or no sleeve. Wet sleeve diesels require a anti-cavitation additive. Dry sleeve or no sleeve engines generally do not need anti-cavitation additives

Gas engines, the newer auto types also have some cavitation issues. For bigger engines it's far more of an issue. For a dinky 3gm30F like mine, it's a non-issue.

[a64pilot]

Originally Posted by CarlF

.



While there may be disagreements on color, I'm quite sure that "not green" is important - at least in the 4JH4's. You want a name brand Extended Life or Long Life coolant.

I’m pretty sure that Yanmar depending on year has used what amounts to Dexcool coolant. It’s off the top of my head an organic acid based coolant, really is long life, low silicate so it doesn’t eat water pumps, and I want to think more environmentally friendly.

However it does not mix with other coolants and if you don’t take care of your cooling system it can cause problems.
Google Dexcool lawsuits.

You can switch to other types of coolants, but only after a very, very thorough flush.
I’d just add water clean enough to drink and not get too wrapped up about how pure it is, this isn’t a battery. Then unless you know how long it’s been since it’s been changed, I’d clean my heat exchanger and then flush the cooling system very well and use your favorite brand of coolant.

[thinwater]

Originally Posted by CarlF

While I am no expert I don't think I've ever used the Yanmar brand coolant in my Yanmar 4JH4's. My manual specifies Texaco or Havoline. They don't even mention Yanmar coolant.

The boat builder used Texaco and put some spare jugs onboard.

While there may be disagreements on color, I'm quite sure that "not green" is important - at least in the 4JH4's. You want a name brand Extended Life or Long Life coolant.

In any case, get the premixed so you don't have to worry about finding deionized water.

I spent the last 25 years working in the coolant industry as a chemical engineer. There are a lot of declarative statements in this thread that sound true... but are not.


If the manual says Texaco (probably Dexcool) then that's pretty simple.



Yes, HD coolants are ONLY required for wet sleeve engines, and in fact, Dexcool is quite good for light duty and non-sleeve diesels.


If you just need a little, the water you would use for your batteries is probably good--the water specifications are similar. Otherwise, the manual is the best bet. Mixes can be bad. They usually are not. But they can be.

[SailRedemption]

Shell diesel coolant. It was mentioned before, I'm away from the beach at but I did SIGNIFICANT research into this including calling yanmar the Shell coolant is the EQUIVALENT of the Yanmar listed coolants. It's a premix so you don't need to add water.

[Wotname]

Originally Posted by redsky49

I think posters are misusing some terms.


De-ionized water, also referred to as "hungry water" in lab applications, will attempt to regain that missing ion. In doing so it will take what it needs from whatever surfaces it has available. This is not good for water purity, nor for the donors of that lost ion. Frequently I have used glass piping to maintain water quality when faced with de-ionized water.



Instead use distilled water, water that has had most of the mineral content removed.

Perhaps but then again perhaps not...

If this was a lab application then I would ask you what is best however for a small marine diesel in a cruising forum I think any of the following would be sufficient - distilled water, demineralised water (de-ionised water), potable water.

In this part of the world, distilled water is more difficult/expensive to obtain because it has to be actually distilled before it can be sold as such.

The greater harm will be to mix incompatible engine coolants.

Clearly this stuff is Superior

[sailorchic34]

Originally Posted by thinwater

I spent the last 25 years working in the coolant industry as a chemical engineer. There are a lot of declarative statements in this thread that sound true... but are not.

If the manual says Texaco (probably Dexcool) then that's pretty simple.

Yes, HD coolants are ONLY required for wet sleeve engines, and in fact, Dexcool is quite good for light duty and non-sleeve diesels.

Good info, Yes I use Dexcool. My old goldwing required it and kept using it for the yanmar.

[Bean Counter]

So when you undo the radiator cap on the engine is there coolant water lapping at the top and it is just the expansion tank that is empty. If so just put distilled water in the expansion tank. Run the engine till warm. Check the expansion tank - if it is empty and the radiator cap still has coolant lapping at the top (after it has cooled) it would seem there is a leak in the expansion tank or hose (could be split, hose clamp loose, etc) I doubt that the dilution impact of the volume of the expansion tank would make much difference to the total concentration of coolant (The coolant dilution range is 40 - 60%). The radiator cap may need replacement too.

[a64pilot]

Originally Posted by sailorchic34

Good info, Yes I use Dexcool. My old goldwing required it and kept using it for the yanmar.

Honda required low or no silicate coolant, regular silicate containing coolant ate the water pump seal.
Honda was requiring non silicate formula coolant, before there was a Dexcool I’m pretty sure.
Scroll down to Organic Acid technology
https://en.m.wikipedia.org/wiki/Antifreeze

On edit, not sure if we really need extend life coolant, perhaps just plain ole Prestone green is fine, maybe we should be cleaning our heat exchangers every other year or so and doing a coolant flush?
Myself I have gone with GO5 or Hybrid Organic Acid coolant.

[Paul L]

Yanmar service bulletin on coolant from Mack Boring site

TO: MARINE DISTRIBUTERS
COOLANT ADDITIVES
After testing some popular coolant/anti-freeze solutions, we have reached the following
recommendations. It was not possible to test all brands on the market, so there may be some
solutions that are acceptable but have not been tested. However, caution is advised if using other
than approved brands.
Regardless of the recommendation of the coolant/antifreeze manufacturers it is YANMAR'S
requirement that the solution is changed every 500 hours (On the YANMAR Model 6LP 250
hours) or once a year whichever comes first.
We do not recommend any other additives be added to the cooling system. Purified or distilled
water mixed with the approved coolant/anti-freeze is the only protection approved by YANMAR.
Concentrations of the Enix-ture should follow the recommendations of the manufacturer. The
coolant/anti-freeze must be compatible with aluminum.
Advantages of this type of coolant:
• Improved water pump life due to reduced water pump seal wear resulting from fewer abrasive
dissolved solids.
• Reduces hard water scale.
• Offers excellent protection against pitting corrosion caused by cylinder liner cavitation. Better
heat transfer than conventional coolants with regular SCALE additions.
• No silicate gel formation during use or storage.
• Outstanding hot surface aluminum protection.
• Superior protection in high operating temperature conditions.
• Effective, long-term corrosion protection for aluminum, brass, cast iron, steel, solder and
copper alloys.

The coolant/anti-freezes that have been tested and approved are shown below:
• Texaco Long Life Coolant Anti-Freeze both regular and pre-mixed Product codes 7991 and
7998. This product is available in gallon containers, drums and bulk. It is recommended that the
cooling system be drained and flushed before filling. Only Texaco Long Life Coolant should be
used for top-off. This product has a much longer shelf life than conventional coolants provided
the integrity of the container is maintained. For additional information and availability contact
Texaco at 1-800-782-7852.
• Havoline Extended Life Anti-Freeze/Coolant. Product code 7994. This product is available
through Texaco gas stations, Procedures are the same as with Texaco Long Life Coolant Anti-
Freeze.
• Dex-Cool Long Life Coolant. This product is available through GM service centers worldwide.
• Prestone Extended Life Coolant. Product code AF888. If the above coolants are not readily
available, Prestone Extended life coolant is satisfactory.

[Dockhead]

Originally Posted by Paul L

Yanmar service bulletin on coolant from Mack Boring site

In other words, use OAT coolant only (the pink stuff), and never the green stuff.

When I bought my boat, there was pink in the main, and green in the generator and central heating system. After a lot of research and tech support calls, I determined that both generator (driven by a Yanmar 3TNC74 industrial engine) and central heat system could also use OAT (Dexcool type) coolant provided I thoroughly flushed out the green first. Which I duly did. That was nine years ago.

Just change it often! Yanmar says every year. Most people neglect this I think.

[SailRedemption]

The Shell coolant is red/pink.

[a64pilot]

The Organic acid coolant should be good for years, at least 5 for the average sailboat owner.
However we should be cleaning our heat exchangers more often than that and that requires new coolant or maybe draining and saving the old.

I was initially going to use very long life coolant meant for over the road trucks and topping it off occasionally with its additive like is done on the big trucks. It would have worked very well.

However as was pointed out to me on this site, the potential for possible salt water contamination negates any advantage of true long life coolant, that we need frequent change intervals to handle that possible contamination. ( it takes an astonishingly small amount of sea water to ruin coolant)

So use OAT (orange stuff usually)
Or HOAT (yellow stuff usually, or clear)

However as has been pointed out, color doesn’t guarantee anything, there is no requirement to color code coolant, so not all of it is, it’s more of an industry standard than a government requirement.
So there is coolant out there that does not match the standard color codes, so read the label, don’t just go by color.
Some have apparently been selling the cheap regular glycol stuff, colored orange, cause the OAT coolant is more expensive, so they are masquerading as the expensive stuff, when they are not.
They are not breaking any laws though.

[Paul L]

Originally Posted by Dockhead

In other words, use OAT coolant only (the pink stuff), and never the green stuff.

When I bought my boat, there was pink in the main, and green in the generator and central heating system. After a lot of research and tech support calls, I determined that both generator (driven by a Yanmar 3TNC74 industrial engine) and central heat system could also use OAT (Dexcool type) coolant provided I thoroughly flushed out the green first. Which I duly did. That was nine years ago.

Just change it often! Yanmar says every year. Most people neglect this I think.

As noted above, color is not a reliable indicator.