Sacrificial Anodes?

[Compass790]

Here is a vid that might be useful if OP hasnt found it already:

NB. there is no anode shown on the heat exchanger in the 2GM20F service manual.

https://www.youtube.com/watch?v=N55eY9WIzco

[Wotname]

Originally Posted by Compass790

Here is a vid that might be useful if OP hasnt found it already:

NB. there is no anode shown on the heat exchanger in the 2GM20F service manual.

.........

That is because Yanmar used cupronickel for the heat exchanger and the accepted wisdom is cupronickel doesn't require anodes in salt water.

I have always assumed Yanmar knew what they were doing when they decided to use cupronickel.

[Compass790]

Originally Posted by Wotname

That is because Yanmar used cupronickel for the heat exchanger and the accepted wisdom is cupronickel doesn't require anodes in salt water.

I have always assumed Yanmar knew what they were doing when they decided to use cupronickel.

I never assume yanmar knows what they are doing after looking at their exhaust elbow design & materials on our Yammer.


Luv to have an argument ( u mitea noticed lol) but no argument with cupronickel & how good it is & Yanmar did well selecting that.
I was merely posting about the 2GM20F heat exchanger as OP is a mechanical newbie & mpersena & boatpoker may have confused her so that she is looking for an anode on her heat exchanger.
But hey maybe the confusion is mine.
It would be good if she posted the pic of what anode she is looking at.
Suspect it will be a block one in the coolant circuit of her 2GM20F intended for the raw-water-cooled version.

[GordMay]

Greetings and welcome aboard the CF, mpersena.

[djousset]

Yup, still here and still a little bit confused although the posts have helped me identify certain things. I replaced the mixing elbow and hose. I then tried to remove the end caps of the heat exchanger..... the bolts wouldn't budge so I'll be going back at that soon. Hopefully the anode/no anode will be clear to me then.

[Compass790]

Originally Posted by djousset

Yup, still here and still a little bit confused although the posts have helped me identify certain things. I replaced the mixing elbow and hose. I then tried to remove the end caps of the heat exchanger..... the bolts wouldn't budge so I'll be going back at that soon. Hopefully the anode/no anode will be clear to me then.

Try penetrating oil on your end cap bolts, leave soaking overnite. It may also help to try & undo when the engine is hot ( not running of course ! ) if you cant budge them when its cold.
Again you dont have to worry about the anodes, if fitted they will be in the head & block so they are in the freshwater/coolant circuit. This is a seperate system from the saltwater. So there is no need for the anodes as mentioned earlier by Wotname.

I recommend you read chapter 8 of the service manual available in the CF library & that may help make it clear to you. It has diagrams & exploded view.
Accept that it may be a foreign language to a mechanical newbie but the diagrams should help a lot.

If you cant find it PM me & I can send you a free copy if you want.

[Compass790]

Forgot to add there is a recent post in the engine forum about removing stuck exhaust manifold bolts which should help you in your attempt to remove the heat exchanger end caps.


I would add giving the bolt heads a few raps with a hammer as well before you attempt to undo. You want to avoid breaking a bolt off as they are a PITA to deal with.