Diesel Coolant color type to use

[GordMay]

Originally Posted by MicHughV

I'm no expert on the matter.....but isn't just adding water a coolant ?? The colored stuff is really just an "anti-freeze", really only required in northern climes ...

Absolutely not, as Sailmonkey notes [and more].

[MicHughV]

ok, I get that, but the heat exchanger usually has a small plastic reservoir situated near the engine to allow for expansion and contraction of the coolant....that seems to be the only place air can get to the surface of the water...it's pretty much a closed system elsewhere...

I do add coolant, but typically only a cupful or two....not sure where I learned to do this or why...but I've gone thru' a variety of diesels now and never had an issue...

I've done the same to my vehicles.

When I buy coolant there is usually a chart on the back that recommends certain ratio's of coolant to water depending on expected temps, etc.

The constant flow of seawater thru' the exchanger appears to keep the engine running relatively cool....

I know my way around engines, but the cooling system is a bit hocus pocus to me....

I did have a raw water diesel in my early years, a Volvo, it required a regular cleaning of the cooling chambers, pipes and hoses, from time to time, but that was seawater...it was a pain in the rear end for sure...

[GordMay]

Originally Posted by MicHughV

...I know my way around engines, but the cooling system is a bit hocus pocus to me ...

Indeed, so it appears.
I admire your honesty.

[dannc]

Antifreeze/coolant, which are really not good names, but I can not think of a better word, does the following:

• Raises the boiling point of the coolant
• Has, or should have, anti scaling properties
• Has, or should have, anti corrosion properties
• For some/many diesel engines they can have cavitation of the coolant which can cause damage. This is one reason to use a coolant made for diesel engines since diesel rated coolant has anti cavitation properties.
• Oh, yeah, keep the coolant from freezing.

And to repeat, color has nothing to do with the properties/chemistry of the coolant, nor which engine should use, or not use, said coolant. One has to read the manual to know what the engine needs and read the coolant label to see if it matches the manual.

Later,
Dan

[MicHughV]

good to know....I go to Walmart and get whatever is on the shelf...I do read what is sez on the container though, but it's mostly meaningless to me.......but the same product goes into vehicles...the diesel...the genset...I put it in there and forgetaboutit...will check the reservoir is about the extent of my coolant knowledge...I'll be a bit more diligent now....

[GordMay]

Originally Posted by dannc

Antifreeze/coolant, which are really not good names, but I can not think of a better word, does the following:

• Raises the boiling point of the coolant
• Has, or should have, anti scaling properties
• Has, or should have, anti corrosion properties
• For some/many diesel engines they can have cavitation of the coolant which can cause damage. This is one reason to use a coolant made for diesel engines since diesel rated coolant has anti cavitation properties.
• Oh, yeah, keep the coolant from freezing.

And to repeat, color has nothing to do with the properties/chemistry of the coolant, nor which engine should use, or not use, said coolant. One has to read the manual to know what the engine needs and read the coolant label to see if it matches the manual.

Later,
Dan

For years, formulators added metallic salts, like nitrites and molybdenates, to coolants, that attach themselves to the cylinder liner, and form a sacrificial layer. When the coolant bubbles implode, the metallic salts absorb the pressure, and break off from the liner surface, rather than the metal itself. These metallic salts naturally deplete over time, meaning you must replenish them periodically, by adding a supplemental diesel coolant additives [SCAs].
The chemistry of hybrid organic acid technology [HOAT] coolants passivates the liner surface, which coats it in a thin inert layer, that provides protection against cavitation and corrosion.
Unlike old-fashioned metallic salts, the additives in HOAT coolants last much longer, meaning you don’t have to replenish the system with an SCA.