Yanmar 1GM10 smoke/vapour

slawosz

slawosz

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Hi,
I took my new toy (Sadler 25) for a good run yesterday. Engine was running for around an hour. When around 80% of power, the smoke/vapour was appearing. Here is the video. I think its rather harmless, as engine is starting fast and does not give any signs of problems, but I would like to slowly investigate the problem.
There is very little smoke when on low/mid revs. Oh, and I will have yet to investigate the smell - if any.
What do you think?

This could be simply the condensation, as water is still little cold.
 
Looks like steam to me. If temperature remains OK, not topping up engine oil too often or leaving an oily film on the water then I wouldn't worry about it.
 
If it persists (hard to tell from the video) it's smoke and would require mechanical attention. But at high power you'd be more likely to get black smoke rather than white.
If it vanishes it's steam and probably indicates insufficient cooling water flow or a constricted exhaust elbow. If steam I think that's much more than you ought to see.
If 1 the injector and next injector pump will likely need a look.
If 2 check waterflow from exhaust and regardless of that result check impeller & weed trap, verify free waterflow though seacock (easy with impeller cover removed) follow cooling water circuit and check for kinks and constrictions in the hoses. Finally if no joy remove rubber hose from the elbow and see if you can check it visually. Probably it'll have to come off but it shouldn't be a difficult job.
 
Thanks. I think its a steam. I will check the water system, although it looks like the exhaust spits plenty of water too. I think there was a buildup of some oily deposits - the first time I gave a full power there was oily water behind etc, but it stopped quickly.
 
One question - somewhere I read that when engine is all OK, elbow, or the engine should be not too hot to touch. Is it true or an urban myth? I will probably have some time during weekend to do some maintenance and this could give me a clue.
 
The Yanmar like most raw water cooled engines runs cool as this reduces the level of salt build up in the cooling passages. You should be able to touch most of the engine comfortably except the bit of the exhaust elbow before the water injection point.
 
That looks like steam to me too and no more than my 1GM makes when working hard on a cold day.

Smoke will linger whereas steam dissipates quite quickly.

Providing there's a reasonable flow of water out of the exhaust accompanying it and the engine isn't getting too hot to touch then nothing to worry about.
 
The flow of water is fine. Changed thermostat. The old one opened very little, will attach the photo soon, but it did not solve the issue - the see water is relatively cold but was warm day yesterday when I checked - still steam from exhaust. I inspected the elbow, is almost like new. Changed impeller, as it wasn't changed for some time I believe. The thermostat cover looks good.
I am almost sure it's steam as running on lower revs for some time cools the engine - actually quite quick. Then high revs again and steam appears only after water is much warmer. I can barely touch the water - little painful, but not too much, I think exhaust water is around 60-70 degrees celsius (after experiments with a lab thermometer in the kitchen). I can touch the head below the valve cover, but it is quite hot.
I suppose the head-block passages might be clogged a little, I will give a good flush during winter with Rydlyme and stop worrying for now as engine was running for some time - at least 30 minutes plus it cools when revs drop quite quick.
 
Have you taken the pipework between the pump and the thermostat housing apart, including the T piece that goes into the cylinder? The is all probe to filling up with crud.
 
Tranona said:
Have you taken the pipework between the pump and the thermostat housing apart, including the T piece that goes into the cylinder? The is all probe to filling up with crud.
Click to expand...
Partially. I did removed pipe between pump and T-piece. Did not inspect this one, but the T-piece from pump to the engine looked quite OK. No buildup. I will check those carefully next time I will have chance.

Regarding running engine little too hot, is the any damage to the engine, except more buildup of crud?
 
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