White Smoke and we already have a Pope

[SeaSon]

ARGH.

The white (grey depending on your visual acuity) is straight unburnt diesel from cyl 1. Loosening the injector line on cyl 1 with no change in running smoothness showed cyl 1 is not firing. Fixing the faulty injector will solve the problem.

Charlie, please let us know when the new injector is in.

[1Sunseeker]

Make sure water intake filter is clear. It could just be overheating. Same thing, same story happened on my Yanmar 3YM20.

[Charlie]

Can't believe it has taken me this long to get to the boat and work on it. Life gets in the way. ( Well two weeks in Europe)



Above is a picture of my heat exchanger. The impeller looked fine until I removed it. The fins that had broken apart were not visible without removing the impeller. Also I cleaned out the tubes with a brass brush I bought from Harbor Freight. They had closed somewhat though I can't quantify how much. I assume that this is what caused the white smoke. I am awaiting "O" rings from Yanmar and then I will put it back together and see if this has resolved the problem.

[delmarrey]

This seems to be a common problem!
I really think there should be a strainer between the pump and the heat exchanger. Even if the impeller is inspected or replaced on a schedule, all it takes is one over heating from a closed valve or a plastic bag over the inlet, to burn the impeller enough to crack/burn the rubber.

Normally inspections are every 250 hours, and replacement at 1000 hours, or 1 year. And winterizing here in the PNW its common to remove the impeller and spray it down with silicon, if its fairly new, and replace in the spring. Carrying a couple spares is a good idea, too.

[Charlie]

After doing all that work I took my boat out for a test and the engine overheated not more then a quarter mile from the slip. I nursed the boat back and had an adventure. (see http://www.cruisersforum.com/forums/...ng-176832.html ) Turns out that there was some kind of chemical reaction with the coolant. Perhaps it had worn out or perhaps I had inadvertently mixed the wrong kinds of coolant together.

Whichever way I took the existing coolant out flushed the engine with cold water three times. Ran the engine with the raw water in between flushes for 20 minutes and added new purple coolant (the old one was green. I think the purple is dex cool but not sure) and overheating problem gone. I guess Yanmar's are very particuilar about their coolant. I did not know that.

[delmarrey]

Yes, Yanmar is particular about coolant. But by flushing it maybe you broke a blockage in the system. The type of coolant wouldn't really change the cooling process that much. But its the protection that it provides in the importance.

Heres a pict from the manual......

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[delmarrey]

Here is the continued coolant section.......

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[Charlie]

Thnx Del. Didn't think of breaking a blockage. For whatever reason it works fine now.

[westwinds]

Originally Posted by SeaSon

ARGH.

The white (grey depending on your visual acuity) is straight unburnt diesel from cyl 1. Loosening the injector line on cyl 1 with no change in running smoothness showed cyl 1 is not firing. Fixing the faulty injector will solve the problem.

Charlie, please let us know when the new injector is in.

I was also thinking raw diesel, no combustion. Is there a strong diesel odor?

[topmast]

Unless you located and removed a chunk of rubber impeller (probably in an elbow) it's stiil there waiting to re lodge. Bet the problem is injector related. or sticky valve