Yanmar overheating advice?

[SeacretSailor]

I'm getting high temp alarms on my Yanmar 2QW15 (raw water input) after it reaches operating temp. I know the cause, just need a suggestion on addressing the issue. It's not the water pump/impeller, engine zincs or a stuck thermostat, it's lack of use during the 2 hot summer months that I don't sail.

I keep my C&C-29 in the warm humid waters of Lake Pontchartrain, north of New Orleans and I don't really sail much between July - mid-September due to the weather. I'm pretty sure that the issue is I'm getting growth or blockages inside the engine from it sitting idle for 2 months, and the engine will get hot. Eventually after running it for a few hours, it'll clear out, flush out and run OK.

Question - I know the solution is even though I don't sail for 2-3 months, I need to go run it for 20-30 min on a weekly basis, but is there anything I coould run thru the engine to flush the slime or blockages out? I have a "T" plumbed into water pump, so it'd be easy to close the seacock and run a bucket of something + water thru the engine.

This week I need to go run it and clear the block out and get some good clean water to flush it, but I know that for awhile, I'll get an alarm and the engine will get hot and overheat before it clears. I open the hatches and run a fan into the engine hatch to help cool, but I'm hoping someone will know if there's something beneficial I could run thru the block with water to help flush/clean out the inside of the block?

 

[sailaway78]

I live in the same area

And do not have such a problem. Many friends of mine also have boats in your immediate area, and do not have this problem as far as I know. The water is a lot warmer during this time of year, and mine does run about 10 degrees warmer than during cooler periods. If your sure it is not just running warmer due to the raw water temps, you might try running a mild bleach solution through it. Bleach would probably kill any algae growth, but don't know about any hard growth you might be getting.

 

[PSTEVEN]

I do not have a better answer for this time, but why don't you use the tee to run either fresh water or better yet antifreeze into the engine before you shut down for next summer. That should help to keep any growth down

 

[seadaddler]

Don't think

I think it's more than what you think it is but any way I leave my boat unused for about 2 or 3 months in the summer and so many other sailors here in Florida do it too and have never heard of such a problem.
Any way yes you could start using that tee to flush with fresh water mix with bleach and see how that works but you could have some kind of growing internally in the cooling system,I have seen a salt away flush system or have also heard of using with your tee adding I think but not sure but muric acid into the system and let it sit for 15 minutes or so and than flush with fresh water.
Maybe some one else will jump that knows better about what to use to flush the system out.
Nick

 

[seadaddler]

Mixing Elbo

When was the last time the mixing elbo was checked.
Nick

 

[Benny17441]

Check the water flow coming out of the exaust. If it is somewhat weak then you may have salt and gunk deposits blocking one of the hoses. Those deposits tend to form when air is introduced into the raw water system. If you close the intake valve and then there is a leak in the system the residues will dry out and form a plug over a period of time.

 

[kloudie1]

Just worked this on a buddy's boat (2QM20) a little closer to the lake on the same bayou.. Three of the hose nipples on the engine had a plug of "stuff" in em. The return line from the hot water tank was the worst.. He didn't have a raw water strainer and we also got some shreaded fish parts out of the thermostat.. The water flow seemed good but it was all going through the bypass line and not going through the engine.