Oceanis 36cc -change coolant how often and how

[carlager]

We have a yanmar 3gm30f engine in our Oceanis 36cc. I have not changed the coolant for 3 years, but have been advised to do it.

I would like to hear how often other change their coolant and tips and tricks on how to change the coolant. ( i have located 3 drains. 1 on each side of the motor and 1 on the hose to the water heater)

 

[Dan Hill]

I would test the coolant before going through the process of changing it. Coolant is not subject to contaminants like motor oils and doesn't need regular replacement. I test mine annually for freeze protection and inhibitor concentration and adjust as needed.

 

[alanwir]

Coolant Replacement

Hi Carl:
I am much like what Dan has explained, however there is a key issue to this whole matter. Yanmar had always suggested that you do not use the green anti freeze and that one use the Long Lasting Red antifreeze made by the likes of the old Texaco. Latter, some manufacturers were suppose to have come up with long life AF, other than Texaco.

There seems to have been a problem either way you go with this thinking.
If you use the "green colored" antifreeze, there is supposed to be higher concentrations of silica in that product which will eventually clog your heat exchanger. If you go with the long life product, particularly with that which was call the "red colored" AF, there were reports with autos in the earlier years having cracked blocks and this red AF was suppose to be the root cause.

My boat came new with the green AF and I tried to change it out every 2-3 years as my solution to this concern. Perhaps there is a newer long life AF out there now with a different stabilizing package that works better.

 

[Bob846]

Carlager,
I also had a 36cc with the same engine. I usually changed the coolant every 2 years. If you do a internet search on "yanmar coolant" you will find many recommendations. I trust the following: http://ldmarineservice.com/files/yanmar_bulletins.pdf.
Best of luck....Bob E.

 

[Davefromoregon]

Yanmar has engine user guides available for download. At least for my engine it describes all periodic maintenance along with intervals. Try to find that document for your engine.

 

[Gunni]

5years using the Yanmar-recommended Texaco-spec long-life antifreeze.

 

[Tejas]

Not based on actual knowledge but rather on posts on other forums, apparently changing coolant types without flushing the system can cause problems.

 

[Gunni]

Not based on actual knowledge but rather on posts on other forums, apparently changing coolant types without flushing the system can cause problems.

Yes, you want to flush the system. A good idea if you have no idea of the age and type of the existing AF.

 

[knot smart]

Not based on actual knowledge but rather on posts on other forums, apparently changing coolant types without flushing the system can cause problems.

absolutely ..never do a quick change ..the two kinds (red & green) are not compatable.. if you mix the two they get clumpy..thats bad

if you going to change color/types you have to make sure you drain every bit , hoses, engine, water heater, ect..

if youre not changing types just drain what you can and top off with new.. I change mine every season..

good luck

 

[Beneteau 321]

What brand/make of coolant do you use (our B 321 with Yanmar 3GM30F is green)
Also do you use premixed antifreeze?
Thanks in advance for all info

 

[knot smart]

I use AC DELCO DEX-COOL and I cut 50/50 with water. its the orange/red color..the yanmar brand is the same orange/ red color.. I never buy premix, its not bad, but you get more bang for your buck buying straight uncut and mixing yourself. the yanmar jug was left on the boat when I bought it, I just use it to make the 50/50 mix.

 

[carlager]

I use AC DELCO DEX-COOL and I cut 50/50 with water. its the orange/red color..the yanmar brand is the same orange/ red color.. I never buy premix, its not bad, but you get more bang for your buck buying straight uncut and mixing yourself. the yanmar jug was left on the boat when I bought it, I just use it to make the 50/50 mix.

Thanx for the info and photos. May I ask a couple
questions

1. Is your engine model 3gm30f ?
2. Do you use normal tapwater ?
3 is the AC DELCO DEX-COOL designed for Yanmar ?

 

[Ron20324]

In the store they have both full strength, and 50-50 mix. You'd think the 50-50 would be half price, but it's not. The new math, I guess. Use distilled water to keep the mineral and "whatever else" is in the local water out of the engine.