White smoke

[Ronald Duncanson]

Billows white smoke when idling ,on the outlet of exhaust black looks like unburnt fuel ,any help would be appreciated

[Bee]

What engine? white exhaust can be steam but it disperses v. quickly (especially in hot weather like now) more likely a fuel prob, start OK? can be timing if you've had the pump off, other than that probably others will know better.

[Tony Brooks]

As Bee said - What BMC, even if we assume its a diesel we can choose anything between 998cc and abut 7 litres.

 

I go along with Bee in respect of steam but is it a wet or dry exhaust boat? What type of boat and what type of cooling system  direct raw water, indirect heat exchanger, or keel/tank cooling?

 

Some history please. What ave you recently had done the the engine  or done yourself? How as this developed? Is the boat new to you?

 

Remember we do not know what you know about your boat.

 

If the boat starts easily from cold and seem to develop plenty of power then It may be the injectors are dribbling and need overhauling. 

 

If this is an old BMC 1.5 and the boat is new to you then maybe the injector drive skew gear oiling system has blocked so the gear(s0 are badly worn. That would retard the injection (so in line with Bee).

 

You may have low compression on one or more cylinders so the air inside does not get hot enough to fire the fuel at idle. The unburned fuel would then vaporise causing white fumes - probably lots. Try turning the engine over with a spanner on the front crankshaft pulley nut and assess the comparative ease with which you can turn it through the four compression strokes.

 

Any oil in the coolant? Is it tending to overheat?

[MtB]

AND....

 

Is the white smoke present all the time when dropping back to idle or does it clear after a bit?

 

Is the engine consuming coolant? (This is why we need to know if cooling is skin tank or raw water.)

 

My immediate guess is head gasket failure from coolant getting into a cylinder but I'm not expert on BMC 1.5/1.8 like Tony.

Edited June 29, 2018 by Mike the Boilerman

[Tony Brooks]

That is why Bee's comment about steam dispersing quickly is so important. Once we can make an informed decision about smoke/vapour or steam the sooner we  can start ruling things out.

[Boater Sam]

Trying to elect a new Pope?

Does the white smoke stink of diesel? Does it leave leave oily spots on a tissue held near the exhaust? When and how did this behaviour start?

[LadyG]

hmmm, thought it was a new pope announcement......................

[Tony Brooks]

If this is a wet exhaust boat and even more so if it is also tank or keel cooled then this would be typical for a worn raw water pump, or pump impeller This is because the volume of water supplied is reduced so what water is supplied turns to stem.

 

Once again a seeming reluctance to answer questions that is rather annoying when the original question was so scant.

[bizzard]

Probably busy doin his Pools.

[OldGoat]

1 hour ago, Tony Brooks said:

If this is a wet exhaust boat and even more so if it is also tank or keel cooled then this would be typical for a worn raw water pump, or pump impeller This is because the volume of water supplied is reduced so what water is supplied turns to stem.

 

Once again a seeming reluctance to answer questions that is rather annoying when the original question was so scant.

On a point of information Mr. Brooks, sir -

I am lucky enough to have a Beta marinised Kubota engine and it (as well as its predecessor) has always had white 'smoke' emanating from its exhaust system. Both senior executives and technicians have dismissed that with the usual 'they do that' explanation. More helpfully it was dismissed as something to do with the water injection arrangement  - even with a ' new and improved'  manifold on the second engine. I gave up worrying about it years ago.

 

I do support your second statement. "not enough information" - but then fewer and fewer folks understand anything about the technology behind the devices that they use.

[Mikexx]

1 hour ago, OldGoat said:

I do support your second statement. "not enough information" - but then fewer and fewer folks understand anything about the technology behind the devices that they use.

 

I don't think things have changed much. Carl Sagan said 30 years ago, "We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology".

[Tony Brooks]

2 hours ago, OldGoat said:

On a point of information Mr. Brooks, sir -

I am lucky enough to have a Beta marinised Kubota engine and it (as well as its predecessor) has always had white 'smoke' emanating from its exhaust system. Both senior executives and technicians have dismissed that with the usual 'they do that' explanation. More helpfully it was dismissed as something to do with the water injection arrangement  - even with a ' new and improved'  manifold on the second engine. I gave up worrying about it years ago.

 

I do support your second statement. "not enough information" - but then fewer and fewer folks understand anything about the technology behind the devices that they use.

The OP said "billows white smoke" and I lay odds yours did not and never has "billowed". Depending upon the length of the exhaust run a wet exhaust may well emit  some "steam" but not "billow".   The times "steam" becomes excessive is when the water supply to the wet exhaust is reduced for some reason so I gave a reason a wet exhaust boat may "billow" white exhaust products. Without any more info its just something else for the OP to check.

 

Also this is headed as a BMC, not a Beta.

[OldGoat]

2 minutes ago, Tony Brooks said:

The OP said "billows white smoke" and I lay odds yours did not and never has "billowed". Depending upon the length of the exhaust run a wet exhaust may well emit  some "steam" but not "billow".   The times "steam" becomes excessive is when the water supply to the wet exhaust is reduced for some reason so I gave a reason a wet exhaust boat may "billow" white exhaust products. Without any more info its just something else for the OP to check.

 

Also this is headed as a BMC, not a Beta.

I'm obliged, sir.

[koukouvagia]

1 hour ago, Tony Brooks said:

The OP said "billows white smoke" and I lay odds yours did not and never has "billowed". 

I can assure you that when something is amiss a wet exhaust BMC does billow.  A small air leak in the pipework caused the Jabsco pump to work inefficiently.  There was a soldered joint in the copper pipe leading to the pump.  This had failed and allowed air to be sucked in, although there was no water leak at the joint.

Even with the pump working efficiently and with all the copper pipe replaced with the proper hoses, I still get a fair amount of steam if the weather is cold.

Edited June 30, 2018 by koukouvagia

[cuthound]

5 hours ago, Mikexx said:

 

I don't think things have changed much. Carl Sagan said 30 years ago, "We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology".

 

The thing that has changed is that even fewer of the population understand it.

 

30 years ago most teenage boys understood the basic principle of the internal combustion engine, not so today.

[Ronald Duncanson]

only white smoke when ideling no problem when under load

[Tony Brooks]

So can we rule out steam? Has the engine model been clarified?

 

I don't seem to have noticed clarification about a wet or dry exhaust system.

 

If this is a dry exhaust boat then something is wrong with the combustion and its probably vaporised fuel.

 

First check the valve clearances in case one or more are tight.

 

Then turn the engine over manually to try to asses how even the four compressions are. If one is noticeably weaker then the head will probably have to come off.

 

If all the above seem OK then I would suspect an injector or injectors are jetting fuel rather than atomising it so they need an overhaul.

 

If this is mainly very soon after a cold start then it could be a glow plug problem or on a 1.5 the glow plugs may need removing & their holes decolonising (far easier said than done normally!).

 

 

 

 

[Tony Brooks]

PS - it could be injection timing but if so I would expect you to list other symptoms.

[BILLYBONGO]

I’ve got same problem with a 1.8 bmc white smoke and top of coolant tank pissing out water on the overflow pipe on cap !!!! I’m a rookie and looking for a bit of advice.   HELP! 

[Tony Brooks]

White smoke when?

Type of cooling system (raw water/heat exchanger/tank cooling/keel cooling) or type of boat?

Any other symptoms and what lead up to it?

How does it start when hot & cold?

 

In view of the scant details you provide I would suspect head gasket but it might be nothing more than than a somewhat neglected engine and air in a skin tank.

 

PS Please start a new topic so we do not have to wade through the last one to see what has been said.

Edited March 24, 2019 by Tony Brooks

[BILLYBONGO]

Ok Tony thank you apologies Will start a new topic. Thanks