I need to replace the antifreeze in my Yanmar 2GMF. This is the internal side of the heat exchanger, not the raw water side. Can I use automotive antifreeze?
Thanks.
Thanks.
Replacing antifreeze
- Thread starter IH82BL8
- Start date
use the shell Clr i think its called there are additives in the anti freeze that help protect the cylinder liners and the interior of the block ...it cost a little more but what the heck is a few bucks when you are talking about an 8 or 9 thousand dollar engine ....you can find it at most truck parts places or bulk plants (oil distributors) and while you're at it use shell rotella in the crankcase
When ya drain the anti freeze, it is really important to flush out all the old stuff with a bunch of fresh water before putting new AF into the thing. There is a lot in the water heater circuit so be sure to get that flushed out as well.. After re-filling, you may have to burp the system a couple of times to get all the air out and the new stuff in. Don't forget to dump and rinse and refill (to the "cold" line) the little expansion tank that connects under the heatex fill cap.
Practical-Sailor did an outstanding evaluation back in October 2014 of diesel coolants and the yanmar wet-sleeve diesel requirements. Another great reason to be subscribed to this publication. In short you are looking for diesel-specific NOAT (nitrited organic acid technology) coolant. The service interval is long too.
When it comes to your engine, forget Practical Sailor and other questionable sources and refer only to the shop manual for the final word !
Seems like Yanmar will accept pure water with rust inhibitor. Antifreeze in the winter time. They don't seem big on spending your hard earned money on the latest boutique, antifreeze craze out there. Mack boring puts a little finer spin on it. Nothing fancy or exotic.
One other trick I've found to avoid the mess of trying to blow all of the coolant out of the lines is to change what's in the block every two years. It comes out quickly and the same volume can be added quickly with no spillage. Spent corrosion inhibitors are being partially removed and partially replaced with new chemicals every other year. The old coolant coming out should be as crystal clear as the new coolant going in. As Ron said, use only distilled water.
Seems like Yanmar will accept pure water with rust inhibitor. Antifreeze in the winter time. They don't seem big on spending your hard earned money on the latest boutique, antifreeze craze out there. Mack boring puts a little finer spin on it. Nothing fancy or exotic.
One other trick I've found to avoid the mess of trying to blow all of the coolant out of the lines is to change what's in the block every two years. It comes out quickly and the same volume can be added quickly with no spillage. Spent corrosion inhibitors are being partially removed and partially replaced with new chemicals every other year. The old coolant coming out should be as crystal clear as the new coolant going in. As Ron said, use only distilled water.
Last edited:
The Yanmar shop manual is pretty much useless generalilities about ion-free water and anticorrosive additives that have no value to freeze-zone boaters. Mack Boring provides recommendations for long-life coolants...then tells you to replace them every year....and flush uncompatible coolants first. Fleetguard ES Complete EG OAT...I may never replace it.
You boat (or engine in this case) your choice. But "may never" could be a little excessive ? ? ? ?
I'm sure it's perfectly good but is it any better than Prestone Extended Life ? All I want to do is prevent corrosion and avoid freezing and the perfectly clear waste coolant (50/50) coming out of my engine (every other year) satisfies me. And I'm not interested in seeing how long I can go without changing until I do see the first signs of corrosion in the coolant.
long and short of it: certain yanmar engines can be damaged by using 'pink stuff' instead of Prestone green . mack boring diesel school told me why but it's along complicated explanation. so ask your Yanmar dealer if your engine is is one of them which needs greeg. my 2GM20F and my 3jh4E both required 'green' not pink. . replacing the coolant and cleaning out the freshwater system every couple years is a good idea, check the hoses , clean the heat exchanger while you are at it...
My 2007 3YM30 has Orange antifreez in since it was new and very soon
I do need to flush and change new antifreez.
Nick
I do need to flush and change new antifreez.
Nick
Originally the long-life coolants were Dexcool variants, tinted orange to indicate difference from the traditional green stuff. Good for 5 years or so. Marine diesels are high load continuous duty engines. The yanmars are wet cylinder engines like most modern light diesels with cavitation corrosion risk. There are coolants for that purpose, and they are diesel-specific coolants.
mine is red and you can get it from tractor supply
http://www.tractorsupply.com/tsc/product/shell-rotella-elc-antifreeze-1-gal
http://www.tractorsupply.com/tsc/product/shell-rotella-elc-antifreeze-1-gal
Our Yanmar dealer sells and recommends Delo (http://www.chevronlubricants.com/en...ded-life-coolant-antifreeze.html#.VlSFVXrEirU) for our 3GM30F engine. I reverse flushed it well and replaced all the engine rubber hoses and clamps before filling it with the new coolant. It is pink in colour. The label claims it is good for 7 years. I'll probably flush and replace it every 3 years.
Bob
Bob
I am surprised to hear about changing your coolants, even if they are clear and no leaks or dilutions.
Why change it?
If you engine is galvanically connected to a zinc (the corrosion inhibitors are only for galvanic dissimilar metals), distilled water was used, and the mix ratio is good for your area freeze protection you should be ok. What has changed since last replacement?
I do a laser temperature pointer survey ( of engine and genset) 2 times a year to see if there is a change in performance.
Jim...
PS: Distilled water is used to eliminate the conduction by the water to prevent galvanic current to flow.
Why change it?
If you engine is galvanically connected to a zinc (the corrosion inhibitors are only for galvanic dissimilar metals), distilled water was used, and the mix ratio is good for your area freeze protection you should be ok. What has changed since last replacement?
I do a laser temperature pointer survey ( of engine and genset) 2 times a year to see if there is a change in performance.
Jim...
PS: Distilled water is used to eliminate the conduction by the water to prevent galvanic current to flow.
There are concerns with metals corrosion and the depletion of anti-corrosive additives in the coolant. There are also concerns with biological activity that can produce acidic conditions and chew up aluminum and other metals, so you want a minimum level of glycol to pickle the coolant against critters. Use a refractometer to measure your coolant glycol content.
The most important reason to use distilled water is to eliminate the scale producing chemicals (calcium and magnesium) found in tap water. This important where the tap water is from in ground wells as opposed to surface run off from rain and snow.
One recommended coolant for the Yanmar 3YM30 is Havoline extended life with no silicates. It is distributed thru Chevron. Couldn't find it locally; had to order online. Mix the concentrated coolant 50/50 with distiller water. If converting from green coolant to extended life (pink), flush the system several times with water before completely draining & replacing with extended life coolant. My understanding is the two are incompatible and will clog the cooling passages in the engine block & heat exchanger if not completely flushed out.