Yanmar engine coolant change

[fairtide]

Yanmar maintains that a yearly change of coolant is needed to maintain the engine and warantee. They warn that claims of long life made by the coolant manufacturers should be ignored. I have learned that mixing brands and formulations of coolant can have nasty effects, so even topping the overflow tank with the wrong product is not good. Yanmar suggests certain products that are compatible with its engines, but I have no idea as to what was installed (some of that will never be removed) and how one goes about removing and then replacing the coolant mix. Distilled water is to be used when diluting concentrate to make the half and half final product.
So, any hints about extraction of the old antifreeze and installation of the new?

[Mariner]

You probably wouldn't ever catch me actually doing this, but my suggestion would be to backflush the entire system with plain water before refilling it.

[jcollins]

Fartide,
You started a good topic here. We have had discussions about this before. I have never changed coolant in my truck or cars in the past. Have I just been lucky?

Is this more important with fwc boat engines? Other than topping off, I have no idea what brand of AF was in there.

[N4QC]

Check out the Yanmar help web page “Quicklinks” coolant section, as well as the general forum cooling section:

http://www.yanmarhelp.com/i_coolant.htm

Other brands of coolant, besides the one specified on the web page can be used but must meet specs. I’ll have to check the supplies locker on my boat to verify that which I use…

Hope this helps…

[N4QC]

Coolant follow up:

The coolant that I am using in my Yanmar 4LH-DTE, upon recommendation of my Yanmar mechanic, is:

Shell Rotella – ELC
Pre Diluted 50/50
Extended Life Coolant / Antifreeze
Diesel Ready CAT-EC-1

Now that it is in use, I am not able to go back to the green stuff. The Shell product is ORANGE, which I believe is the same color as the Texaco coolant, which is recommended on the Yanmar Help web site.

[fairtide]

I have orange stuff in the overflow container, so I have a feeling that the coolant is DexCool or a similar product. My main concern was Yanmar's emphatic wording about changing the coolant every 500 hours or yearly, whichever came first.
I have 42 hours on the clock and the boat is on the hard ready for shrink wrapping. I suppose that a coolant change in the spring would be fine per the Yanmar directive. My cars rarely if ever get a coolant change and the extended life antifreeeze containers often claim a useful life of 150,000 miles (car use) or five years.
There seems to be some reason for marine engine suppliers to specify very frequent maintenance items that are not easy to do. As we all know, just fueling a boat is not like getting gas in your car's tank. It takes a village sometimes.
So, if anyone has the real story on annual coolant exchanges, let us know what's up.

[Donya]

I only use the premix (red stuff) , the right mix, the right water, a small cost compared to a heat exchanger.

And thats my two cents worth...

[Mariner]

I don't think changing coolant every year is necessary in most cases. But I would still follow the manufacturer's recommendations with regard to engine hours. And if you're one of those people for whom it would take ten years to accumulate that many hours, perhaps you should find the time to at least make it happen every 3-4.

Changing and flushing coolant systems does more than just get fresh coolant in there, it removes debris and contaminants, which are bound to find their way in eventually. Anti-freeze itself does more than just prevent the coolant water from freezing also. It lubricats your water pump and prevents corrosion in the block and heat exchanger. It should be kept fresh. I don't like using anti-freeze that is red in color, becuase it can hide damaging corrosion. With green anti-freeze, you can always tell if you've got corrosion occuring by removing the cap and inspecting the color of the coolant. A brown or red color indicates that a change is immediately needed. But at the end of the day, I'll use whatever coolant is recommended by (in my case) Caterpillar. In my car, I'm more leniant, but when it comes to the boat, the consequences are just too high.

[robonurse]

Use Dex Cool. You can get 50/50 mix right off the shelf at Wal Mart.
It is approved by Yanmar.