Possible cause of white smoke/steam from exhaust!

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steve yates

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I asked about this in a thread a few minths ago, it is still ingoing, and it occured to me it started after the calirifier was connected up. Prior to that the hoses from the engine had the taps clised.
The calirifier isnt actually used and has no water in it, as the water pump diesntvwork.
So after running the engine in neutral fir 15 mins, it felt hot, which may be normal, but so did tge hoses to the calorifier, very hot. And sure enough, the taps are open at the connections. I have closed the taps, ran tge engine again later and it was warm, byt tge hoses wete nit.
Could this be the cause of the steam coming from tge exhaust?
Am i ok yo close those taps where the hoses enter the calorifier? They were closed all year before thevthing was actually connected up.
Thanks.
 
Running the cooling water through the calorifier should not make any difference - assuming it is freshwater cooled. It will of course make the calorifier casing hot because hot water is running through the coil. The water coming out of the exhaust is seawater, so nothing to do with the calorifier.
 
White smoke can be raw deisel in exhaust , faulty injectors,incorrect injection timing , worn or sticking rings ,reduced compression, cylinder glaze,
If it clears when hot probably sticking rings.fouling deposits round rings.
Engines need to be ran hardish regularly , to keep deposits down . If it is always been run a low speeds rarely ever ran up.

Water into combustion chambers , leaking head gasket, crack in head ,liners.
 
If it's white steam then that could, I think, be a sign of insufficient cooling water (strainer blocked? exhaust elbow needs replaced?).
 
Steaming when there was none before is almost certainly due to a reduction in the flow of seawater, whether the engine is raw water or indirectly cooled. In the case of Bukhs, of which the DV10 and DV20 always seem to steam, the usual coolant flow is marginal as the pipework and valves are only 1/2 inch, coupled with the design of the elbow that allows cold water to impinge directly onto the hot exhaust pipe. The slightest obstruction makes the steaming more obvious. A favourite place is the fitting through which water enters the block, behind the flywheel. This used to have very small drilled holes that blocked easily but later ones have bigger holes.

In Volvos the manifold is designed in the same way but the flow is greater, so steaming only becomes a problem when there is a serious accumulation of salts in there. The 2000 series also have a problem with the perforated tube that runs through the engine - blockage of this by salts will increase the temperature of the cooling water, although this tends to divert more through the bypass.

Yanmar manifold design is different, with gases and water in concentric tubes, water outside. This seems to heat the water before mixing occurs, so salt deposition is less and steaming seems quite rare.
 
Nice reply, Vyv. Last year I found huge salt deposits in my engine and associated pipework following a SW leak between the head and mixing elbow. I fixed it before there was any permeant damage (I think).
 
At the risk of doing a "me too", I also have white smoke and would welcome the input from this forum.
  • Engine is a Yanmar 2GM20
  • Injectors were fully serviced last month (which has improved the situation)
  • White smoke only occurs when the engine is warm (i.e. running under load for about 7 mins ) - it's my assumption that this issue only occurs when the thermostat triggers.
  • Engine appears to run fine with good power.

https://youtu.be/OC3oImq0pY8
 
steve yates said:
I asked about this in a thread a few minths ago, it is still ingoing, and it occured to me it started after the calirifier was connected up. Prior to that the hoses from the engine had the taps clised.
The calirifier isnt actually used and has no water in it, as the water pump diesntvwork.
So after running the engine in neutral fir 15 mins, it felt hot, which may be normal, but so did tge hoses to the calorifier, very hot. And sure enough, the taps are open at the connections. I have closed the taps, ran tge engine again later and it was warm, byt tge hoses wete nit.
Could this be the cause of the steam coming from tge exhaust?
Am i ok yo close those taps where the hoses enter the calorifier? They were closed all year before thevthing was actually connected up.
Thanks.
Click to expand...

May I ask - without sounding racist- Is your day job writing instructions for Chinese goods?
Or perhaps a script writer for Allo Allo?
 
RobF said:
At the risk of doing a "me too", I also have white smoke and would welcome the input from this forum.
  • Engine is a Yanmar 2GM20
  • Injectors were fully serviced last month (which has improved the situation)
  • White smoke only occurs when the engine is warm (i.e. running under load for about 7 mins ) - it's my assumption that this issue only occurs when the thermostat triggers.
  • Engine appears to run fine with good power.

https://youtu.be/OC3oImq0pY8
Click to expand...

Is it steam or smoke? Assuming steam, and from a raw-water cooled engine, your third point seems to give the clue as to the cause. From cold, until the thermostat opens most of the raw water is going around the engine through the bypass. When the thermostat opens it simultaneously closes the bypass and lets hot water through to the elbow. If the steaming continues from then on it suggests that the water temperature is too high, probably due to salting up inside the block. I suggest you try the Rydlyme treatment. If my diagnosis is wrong it doesn't matter, still well worth doing assuming the engine has done some hours.

It is worth checking the elbow anyway, as this might be the cause, but as I said earlier my experience with Yanmar is that they do not salt up too badly.
 
At the risk of stealing the thread, and what vyv, if its a 2030 and 'non-raw' cooled. Doesn't smoke cold and progressing increases. Transom does get a bit mucky. Can a Temperature gauge be added on the standard temp sender. Frankly she doesn't seem to get to hot. At 22 years I am thinking of having an 'injector service' and perhaps I should should flush out the coolant.
 
What's the rydleme treatment viv?
Mine is a ygm 30 , and pretty much new. It had 90 hours on it when I got it, and now has about 250.
I did find a chunk of seaweed in the seawater filter there, but I think I might need to investigate the exhaust elbow when she gets into a yard this winter.
 
2 thoughts
Is the thermostat correct ie have you got a fresh water higher setting in a seawater cooled engine
Try short circuiting the calorifier by replacing the long pipes with a short one between the connections on the this may alter the water flow
 
tillergirl said:
At the risk of stealing the thread, and what vyv, if its a 2030 and 'non-raw' cooled. Doesn't smoke cold and progressing increases. Transom does get a bit mucky. Can a Temperature gauge be added on the standard temp sender. Frankly she doesn't seem to get to hot. At 22 years I am thinking of having an 'injector service' and perhaps I should should flush out the coolant.
Click to expand...

I would look at the elbow first. Can't advise about the temperature gauge but I would have thought one could be fitted. Requirements for an injector service are very obvious, lots of smoke especially on start-up, rough running, poor performance, etc. The old guide to detecting steam is to hold a cool mirror in the gas flow from the exhaust.
 
steve yates said:
What's the rydleme treatment viv?
Mine is a ygm 30 , and pretty much new. It had 90 hours on it when I got it, and now has about 250.
I did find a chunk of seaweed in the seawater filter there, but I think I might need to investigate the exhaust elbow when she gets into a yard this winter.
Click to expand...

Check http://www.rydlyme.co.uk/index.php/en/ and http://www.ricoservices.co.uk/environmentallyfr.htm The MSDS shows it to be hydrochloric acid, maybe with something else, and that is a cheaper way to clean it. Others on these pages have used phosphoric and sulphamic acids for the same effect.

250 hours run is not a lot but if the thermostat is not working quite right the coolant temperature could be high, which promotes deposition of salts. Same could apply if the inlet is partially blocked.
 
vyv_cox said:
I would look at the elbow first. Can't advise about the temperature gauge but I would have thought one could be fitted. Requirements for an injector service are very obvious, lots of smoke especially on start-up, rough running, poor performance, etc. The old guide to detecting steam is to hold a cool mirror in the gas flow from the exhaust.
Click to expand...

Elbow was done a few years back. My initial reaction is that it ought still be fine but I'll need to check back how long ago. Engine performance gave not the slightly suggestion of the elbow. Dragging a lot of weed up river yesterday on her bottom, she could pull all the revs as if she was only one year old. I see the injectors are a service item at 400 hours - the hours counter has long expired but at 400 divided by 22 years is 18.181818181818181818 hours per years so it is possibly worthwhile :rolleyes: There is no smoke at all on start-up, no rough running nor poor performance. Frankly if we didn't have a tailwind yesterday I wouldn't have bothered. Er, hanging a mirror over the exhaust tomorrow from TG in a mud berth may just be exciting!:D
 
vyv_cox said:
Check http://www.rydlyme.co.uk/index.php/en/ and http://www.ricoservices.co.uk/environmentallyfr.htm The MSDS shows it to be hydrochloric acid, maybe with something else, and that is a cheaper way to clean it. Others on these pages have used phosphoric and sulphamic acids for the same effect.

250 hours run is not a lot but if the thermostat is not working quite right the coolant temperature could be high, which promotes deposition of salts. Same could apply if the inlet is partially blocked.
Click to expand...

Hydrochloric acid works well. I've used it twice now, with good results on a Volvo 2003. The engine still has a touch of white smoke, but it is much improved from the way it was before using it. Volvo 200x engines are notorious for white smoke, so this is a good result. I close the water inlet seacock, take the thermostat housing off, remove the thermostat, drain the engine by removing the engine anode. replace the anode plug (without the anode, which would dissolve pretty quickly in the acid) and then pour acid into the thermostat housing. I use about 10% HCl, diluted from laboratory strength (my wife is a chemist working in a laboratory with access to acids and such). Leave it for half an hour or so, then simply replace the thermostat and housing, open the seacock and run the engine to clear the acid out. HCl isn't actually particularly harmful to the environment (it's present in things like stomach acid!), so I'm happy about that. Finally, replace the engine anode (when you undo the plug, you'll probably get lots of little black bits of loosened rubbish coming out).
 
vyv_cox said:
Is it steam or smoke? Assuming steam, and from a raw-water cooled engine, your third point seems to give the clue as to the cause. From cold, until the thermostat opens most of the raw water is going around the engine through the bypass. When the thermostat opens it simultaneously closes the bypass and lets hot water through to the elbow. If the steaming continues from then on it suggests that the water temperature is too high, probably due to salting up inside the block. I suggest you try the Rydlyme treatment. If my diagnosis is wrong it doesn't matter, still well worth doing assuming the engine has done some hours.

It is worth checking the elbow anyway, as this might be the cause, but as I said earlier my experience with Yanmar is that they do not salt up too badly.
Click to expand...

Thanks so much, Vyv. I'm pretty sure it's steam as it doesn't have a strong diesel smell
I have done a double treatment of Rydlyme by taking out the thermostat, draining the sea water from the block, filling with Rydlyme and leaving overnight. I'll redo this again this winter. I will also take the exhaust elbow off and have a look at this as well.
 
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