Diesel bug

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DownWest

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About four yrs ago, a local friend with a big steel residential barge, asked me to help with sorting the engines. Two Iveco 6 cylinder 120 hp . Problems with starting.
Had to pull both injector pumps and have them rebuilt, not cheap. One had actually sheered it's drive.
Prob was a gummy deposit. He had used bug treatment, bearing in mind that his tanks are in the ton range. One big one and two wing tanks.
Anyway, more recently we had to sort one of them again, not so bad, but decided to raise the pick up points in the wing tanks. Filters not too cruddy.. Spares for the CAV pumps are getting a bit tricky.

Yesterday I dropped in for a cuppa and he had seen something on the web about a guy with a narrowboat, that had similar probs. The engineer that worked on the engine said that the treatment for diesel bug can cause a gummy deposit that blocks filters and causes other probs.

Anybody else seen anything about this?
 
Although most bug treatments are quite effective, they have limits, depending on how bad things are.
I,ve needed a shovel to remove the jelly- like gunge on some boats and no amount of bug treatment would have sorted them out. In your case it,s possible that the treatment may have partially softened up the gunge and some has found its way into the supply circuit. You really need to open up the tanks and confront the problem at source.
 
lusitano said:
Although most bug treatments are quite effective, they have limits, depending on how bad things are.
I,ve needed a shovel to remove the jelly- like gunge on some boats and no amount of bug treatment would have sorted them out. In your case it,s possible that the treatment may have partially softened up the gunge and some has found its way into the supply circuit. You really need to open up the tanks and confront the problem at source.
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The tanks are really big and not accessable. I did cut a hatch in one of the wing tanks, but only big enough to get a view.
 
lusitano said:
Although most bug treatments are quite effective, they have limits, depending on how bad things are.
I,ve needed a shovel to remove the jelly- like gunge on some boats and no amount of bug treatment would have sorted them out. In your case it,s possible that the treatment may have partially softened up the gunge and some has found its way into the supply circuit. You really need to open up the tanks and confront the problem at source.
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Agreed. We are fortunate enough to have a 600mm diameter manhole so we can climb into the 500L diesel tank. We also have a 1" bronze port in the lid so we can insert a separate filtering system to vacuum the bottom of the tank to remove sediment, dead diesel bug, etc. It works well
 
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Graham376 said:
I've been using Fuel Set for many years and so far no bug. Fuel Set | Liquid Engineering UK Ltd
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Unfortunately it doesn't prove anything. I have owned my boat for more than 30 years, never used fuel treatment of any kind and never had diesel bug. I drained and emptied the tank for removal about 10 years ago, it contained a small amount of sludge that was easily removed by hosing with water.

I do ensure that water cannot enter the tank through the filler cap and mostly buy fuel from mini-tankers that have rapid turnover.
 
Sandy said:
Two key words.

What sort of usage do the engine have?
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Monthly test runs, with a bit of load. Also has a diesel bow thruster (65hp), but no problems there. Fed from a small tank close to it but that is off the main tank. Occasionally he has to reposition in the Marina due to dredging, but other than that, it stays put.
 
DownWest said:
Monthly test runs, with a bit of load. Also has a diesel bow thruster (65hp), but no problems there. Fed from a small tank close to it but that is off the main tank. Occasionally he has to reposition in the Marina due to dredging, but other than that, it stays put.
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A major reason why he has the bug.

He may as well remove the big tanks and just run the engines from the day tank.
 
I have been saying this for years and few seem to get the point of my posts ... they carry on using Bug treatment XX and then wonder why their filters are blocked solid ...

Most treatments out there are designed to kill just a the few bugs that get into your system when refilling. What they do - is to kill the bugs .. which then drop to bottom tank. Repeat enough times and you end up with sludge in tank bottom + the naturally dieing bugs ... this can then get sucked into fuel system and bingo - fliters clogged up.

I have recc'd many times that for real effective treatment - you need Enzyme based that not only KILLS but then also BREAKS up the dead bugs and sludge to allow it to pass through filters and get burnt in the engine.

Fuel Polishing is only a 'band-aid' as it is only filtering out crud ... its not curing or solving any other part of of this problem. Syphoning off and standing fuel will do just the same as some fancy pump and pipe affair ..

The problem for such as Post #1 ... the problem has been allowed to accumulate .. to then be a major undertaking to solve. Emptying of tanks ... removal of sludge in bottom ... treatment and if you have it - filtering of the removed fuel into clean containers. Let stand with an Enzyme treatment .. syphon off clean fuel - leaving crud in containers .. heavily dose this fuel again with Enzyme treatment and put back into tanks .... let the Enzymes do their work ...
Have at hand a couple of filters - as you most likely will clog a filter ... DO NOT KEEP engine plugging away if filter is clogged ... you may open a bypass and then it will clog the injection pump intake ... CHANGE filter at reasonable interval ...

Once the tanks are reasonably clear - then you can use your usual treatment ... but I would suggest that Enzyme treatment is used once or twice a year .. or each time preferably .. this should then help keep your tanks clear and engine running well.

Because I am in the Fuel Business - I will not endorse a brand name ... all I suggest is that you check details and specs of the treatment before buying.
 
The better fuel tanks are tall and narrow, and taper towards the bottom. The best fuel tanks have that and also a dirt/water sump. Every movement of the boat encourages any dirt or water to fall into the sump, from where it can be drained out.
 
NormanS said:
The better fuel tanks are tall and narrow, and taper towards the bottom. The best fuel tanks have that and also a dirt/water sump. Every movement of the boat encourages any dirt or water to fall into the sump, from where it can be drained out.
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???

Quick experiment :

Take a clear container and put some crud in the bottom ... now carefully put in water or whatever fluid you like. Let it stand.

Then mimic the action of a boat ... I think you'll find that the crud / fluid will be agitated and crud LIFTS into the fluid ....

Basically the design of 'sumps' are for crud / water to drop into them when tank is not moving about ..
 
Refueler said:
Because I am in the Fuel Business - I will not endorse a brand name ... all I suggest is that you check details and specs of the treatment before buying.
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Without asking for your endorsement does Startron qualify as an enzyme treatment? And do you think there is anything better that a normal yachty could buy in the chandlers?
 
Refueler said:
???

Quick experiment :

Take a clear container and put some crud in the bottom ... now carefully put in water or whatever fluid you like. Let it stand.

Then mimic the action of a boat ... I think you'll find that the crud / fluid will be agitated and crud LIFTS into the fluid ....

Basically the design of 'sumps' are for crud / water to drop into them when tank is not moving about ..
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Your understanding of the Laws of Gravity are not the same as mine. However, if the dirt or water gets into the sump, whether the boat is moving or not, the sump has achieved its purpose, and the dirt/water can be drained out.
 
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