Engine anode problem

Tylo

Member
195
111
Sweden
Hello,

I've recently bought my first very own boat and although I've always had boats in the family I don't have much on-hand experience with engines in particular.

Anyway, I went to change the impeller and zinc on the new-to-me raw water cooled Volvo Penta 2001. The impeller change went great but when I went to change the engine zinc/anode I ran into a bit of an issue.

It seemed like the zinc had expanded and become porous/soft rather than get worn away (not sure how this happens... not used enough?) so when I went to pull it out, it got stuck in the hole and a chunk came off and remained inside the engine.

I've spent the better part of the day trying to fish the pieces out with everything from a pair of pliers to some steel wire to a vacuum cleaner but I can't seem to get a hold of them. I think my next course of action would have to be to partially disassemble the engine which I find quite intimidating, but before I do that I wanted to ask if anyone here has faced a similar issue and how you solved it.

I also wanted to ask on the off chance that these pieces don't present any real danger to the engine and can be left in there, but I was worried that they would get stuck in the cooling passages and cause issues further down the line.

I've attached a picture of what the anode looked like after I'd pulled it out. Any advice or comments are welcome even if it's calling me an idiot for extracting it the wrong way or something - I don't want this to happen the next time I have to change one of these so if it's my fault please let me know!

Thank you very much.

Anod motor.jpg

 
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It's not going to be the end of the world to leave some zinc piece in the cooler.  If you don't mind the mess it will probably flush out the zinc port by opening the raw water inlet for a while and using your wire to mess with.  Otherwise just leave it be.  Zincs do as pictured to protect the other metal parts.  The part that sluffed off will break down and flush out in time.

 
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Tylo

Member
195
111
Sweden
There is often (probably usually) a protocol for flushing coolant passages.  Checked the manual on-topic?
I've checked and the only reference to flushing the coolant system is to do so using 50/50 fresh water/antifreeze when winterizing the engine.

The part that slugged off will break down and flush out in time.
If this is true I feel more comfortable with not opening the engine up. I was worried it would travel further and block a coolant passage or something like that which may make them even harder to remove.

 

El Borracho

Verified User
6,694
2,661
Pacific Rim
My heat exchanger, a Beta 38, gets well clogged with bits of the anode. They do not dissolve in my case. Perhaps because the crumbs have no electrical potential across them.

Anodes do seem to erode in different ways. Anyone know why some choose to crumble rather than dissolve?

I like to think that more frequent anode replacement helps, but not so certain.

I think the OP should investigate internally as to the situation. 

 

Tylo

Member
195
111
Sweden
I think the OP should investigate internally as to the situation. 
Thank you for your suggestion.

I think I'm going to give it one last attempt with one of these grappling claws but if that fails (which I suspect it will), I may have to try to gain better access to the area.

image.png

I hope this has only happened as a result of neglected maintenance or lack of use and that I won't face the same issue when replacing it next year.

 
El B, you can cut them shorter and change more often to help that.  The Bowman heat exchanger setup Beta uses is only a couple o-rings to disassemble so worth having a bag of o-rings and pulling tube bundle to soak in some muriatic acid once a year or so.  If it's not bad just tube cleaners.  In any case pulling the heat exchanger and cleaning is something that probably should be every two years.  Most set-ups require only simple consumables to do this.  I still haven't done on ours but it's on the list...

 

Tylo

Member
195
111
Sweden
Fleetwood said:
(My) good practice is to replace pencil anodes when still less than half worn, this way they are still mechanically sound. They're cheap.
I will replace these yearly, hopefully that’s enough to avoid this situation in the future. Like you said they’re cheap and easily accessible.

It’s a shame this happened but the boat has spent the last few years on the hard so I would be kidding myself if I didn’t think something like this would come up. It will be interesting to see what the inside of the diesel tank looks like…

Thanks everyone for your suggestions and help, much appreciated!

 




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