Diesel Bug?

[DangerousPirate]

So I recently came here because my engine stuttered a little, thinking "Oh okay, must be some air in the system because the last few times I used it, it worked perfectly well".

The biggest issue seemed how to operate the system as there was no obvious bleeding screw to me.

Now the problem seems to be far worse than previously believed.... Having found a replacement for the screw on the bleeding system I went back to bleeding air, but less and less diesel arrived at the pump, until it was dries up. Weird. I just filled up 2-3 liters yesterday and didn't run the engine since, so might now be much but at least some.

And I notice the diesel in the primary filter has a funny colour compared to the fresh red diesel. So I tried to shut off the valve and change the filter, but the valve is corroded and won't turn!

Okay, that's really bad.

But okay. i burn that bridge when I cross it. For now, the diesel. I did a tricky drain by partially unplugging the bottom of the filter and catch it in a plastic cup. Bit of water in it, and it's more brownish than red.

The filter was drained and despite the open valve nothing came to the filter after it. Hm. Must be because they're almost level, couldn't tell you from the top of my head if the tank is above the filter or the other way around. No big difference.

Okay.... So I decide to change the filter, seizing the moment and all, but I didn't have this filter in particular on the boat. Got everything else. Hm.

So at least I clean the bowl, which was sort of slimey, didn't think anything of it then, and put it all back together.

Having put all my diesel in the tank I didn't have any to fill up the glass bowl/filter so I tried the lever but nothing happened at all. Hm.

Changed the engine filter in the back, hand tightened it and really hurt my knuckles doing so... The other filter had black gunk in it.

Just googling around about the corroded valve I found out symptoms of diesel bug (and the sheer existance!).

This almost fits it to a tee!!! What now? What are sensible next steps?

Can the diesel bug damage the engine? How can I be certain it is that in the first place? Is this going to be very expensive, if it is that?

What else can it be? Gunked up diesel hoses? I admit I don't know how old they are exactly, but the engine seemed well kept from the previous owner and the hoses don't look decades old either, they're still springy.

One thing: the boat has not been moved from beginning of april until end of last month. In april the engine took a little to start (suspecting the cold, but not so sure now..).

And in the last weeks I ran the engine for power on the boat in idle for a few hours a day.

The stuttering started last week or so.

The engine is a beta 14.

 

[ylop]

Yes it could be bug.
Most people don’t ever verify it scientifically (more expensive to test than treat!) but if symptoms fit and treatment works it probably is.
If contamination in minor, drain all water from tank, add a biocide, replace filters, ideally add a parallel filter with switch over valve and carry spare filter so you can change under way.
If it’s worse, then you’ll want to polish the fuel. You can DiY or pay a man. Important to clean tank and system not just circulate the fuel until it is clean.
in terms of expensive - it’s a boat so yes! But in terms of things that can go wrong not too pricey but put the effort in to fixing it properly and keeping it away or you’ll be paying regularly.

add biocide to rarely used tanks, and make sure that water is drained off regularly and condensation avoided.

 

[DangerousPirate]

Yes it could be bug.
Most people don’t ever verify it scientifically (more expensive to test than treat!) but if symptoms fit and treatment works it probably is.
If contamination in minor, drain all water from tank, add a biocide, replace filters, ideally add a parallel filter with switch over valve and carry spare filter so you can change under way.
If it’s worse, then you’ll want to polish the fuel. You can DiY or pay a man. Important to clean tank and system not just circulate the fuel until it is clean.
in terms of expensive - it’s a boat so yes! But in terms of things that can go wrong not too pricey but put the effort in to fixing it properly and keeping it away or you’ll be paying regularly.

add biocide to rarely used tanks, and make sure that water is drained off regularly and condensation avoided.

I will in the future, will replace all the filters now anyway.

The tank though can't be taken out of the boat without removing the engine first. This is the bit that will keep me up tonight.....

How do I know how bad contamination is? I mean, the engine stuttered at first but now completely refuses to work. How would it without any diesel flowing to it? The secondary filter was black gunked, so it is contaminated. The primary filter was lined with slimey see through stuff. So that was obviously contaminated. How much further can it go? Does it damage the engine?


Also not sure how this fuel polishing works? I mean, the valve is still gunked up and dirty, so I'd honestly just dump the tank, which is only a handful of ltrs at best. Wouldn't bother with that. But how do I get the tank clean and the valve to shut and open again? It's barely accessible, I tried to bang it with a hammer a little and wd40, both failed.

And how do I get diesel to flow through again? Does the diesel bug gunk up stuff like hoses to the point of that only replacing them would help?

I suppose it is possible to replace all the hoses, too, but is it necessary?

 

[Slowboat35]

The bug won't harm your engine other than by blocking the fuel system and preventing it from running.

Your description says you've gor a good dose of the bug. The slimy gunk is blocking the feed to the engine either in the filter or the line from the tank.
All it is is a bacterium that deposits slimy snot in the tank that blocks filters and pipes. It isn't harmful per-se as long as it doesn't get past the filters and block the injection system.

Expensive? Depends.
You're going to have to pump your tank out completely and clean it inside.
Pumping it out is the easy bit. Diesel rated 12v pumps cost £20 on ebay. you may be able to do this via the existing feed line to the filter but if much gunk is present that small diameter pipe may well block.

So, gather your ebay pump, a metre or three of suitable sized hose and enough containers to hold the contaminated fuel.

Then the tank needs to be cleaned. Easiest to remove it, pressure-wash/steamclean inside and refit.This can be done in situ, but If the tank doesn't have an access panel you've got a real problem because you need to get inside it to clean it, and no access means no clean tank.
Frankly, if it's old and rusty or you can't get inside to clean it properly just take it out and replace it with a TecTank. That is money well spent.

Once cleaned flush through with a couple of litres of clean diesel.

If feed pipes are blocked consider replacing them. Otherwise blow them through with fuel or air.

Once cleaned and flushed refill tank and add a shock dose of suitable biocide.
I'd change the primary filter after the first hour of running and then a couple of times after that as that initial tankful gets used.

Depending on the amount of fuel you pumped out into cans you can either dispose of it or 'polish' it yourself, that just takes a bit of ingenuity in removing the slime via sieve and maybe a tea-towel & funnel 'filter' followed by a couple of passes through a lashed-up CAV filter and pump setup. Frankly hardly worth the cost of setting up a polishing rig unless you're talking about hundreds of pounds worth of fuel.

Good luck, this is a really frustrating, awkward and smelly thing to resolve.

 

[DangerousPirate]

The bug won't harm your engine other than by blocking the fuel system and preventing it from running.

Your description says you've gor a good dose of the bug. The slimy gunk is blocking the feed to the engine either in the filter or the line from the tank.
All it is is a bacterium that deposits slimy snot in the tank that blocks filters and pipes. It isn't harmful per-se as long as it doesn't get past the filters and block the injection system.

Expensive? Depends.
You're going to have to pump your tank out completely and clean it inside.
Pumping it out is the easy bit. Diesel rated 12v pumps cost £20 on ebay. you may be able to do this via the existing feed line to the filter but if much gunk is present that small diameter pipe may well block.

So, gather your ebay pump, a metre or three of suitable sized hose and enough containers to hold the contaminated fuel.

Then the tank needs to be cleaned. Easiest to remove it, pressure-wash/steamclean inside and refit.This can be done in situ, but If the tank doesn't have an access panel you've got a real problem because you need to get inside it to clean it, and no access means no clean tank.
Frankly, if it's old and rusty or you can't get inside to clean it properly just take it out and replace it with a TecTank. That is money well spent.

Once cleaned flush through with a couple of litres of clean diesel.

If feed pipes are blocked consider replacing them. Otherwise blow them through with fuel or air.

Once cleaned and flushed refill tank and add a shock dose of suitable biocide.
I'd change the primary filter after the first hour of running and then a couple of times after that as that initial tankful gets used.

Depending on the amount of fuel you pumped out into cans you can either dispose of it or 'polish' it yourself, that just takes a bit of ingenuity in removing the slime via sieve and maybe a tea-towel & funnel 'filter' followed by a couple of passes through a lashed-up CAV filter and pump setup. Frankly hardly worth the cost of setting up a polishing rig unless you're talking about hundreds of pounds worth of fuel.

Good luck, this is a really frustrating, awkward and smelly thing to resolve.

No access to the tank......

I looked up biocide. I ordered some now. Plan of action: suck up water from the bottom of the tank (no drain due to access or lack thereof), dump biocide into it, wait a couple of days for it to do it's magic, replace primary filter (secondary already changed), hoping it will allow the diesel to flow again. If it does, run engine often, keep treating the diesel, change the filters again soon and that should be it.

I really wish I could clean the tank though.

 

[Refueler]

Forget all that Polish malarkey ... the organism alive is microscopic ... so polishing does not remove it ... Polishing just removes the gunge - which can be removed without ....

You don't say which Biocide you ordered ..... what you need now is Enzyme based. Enzyme based actually breaks down the crud - which is actually dead bug ... small enough to pass through into engine to be burnt instead of clogging up everything.

But anyway ...

First you need to make sure fuel pipes and filters are passing fuel. For the pipes from tank - I would suggest blowing air from engine end back to the tank - making sure that is clear. Once that's done - Add a strong dose of Biocide tp the tank. Let it work for an hour or so, then using a Pela or similar, (Pela is a good item to have for changing the engine oil ... sucking up water out of lockers ... bilges etc.), empty the tank. Transfer to and let the fuel settle in containers ,,, I use 5ltr Anti-freeze plastic cans - you can see the fuel.
Leave fuel to further settle / biocide to work while we check out tank and engine side.

Using the Pela or suction pump ..... try to remove as much crud / gunge from tank ..... then if possible spray Biocide in tank.

Clean all filter cases ... I like to wipe neat Biocide around the case inside and the fixed parts. We will keep fingers crossed thatg injection pump hasn't suffered (some like older Perkins have a 'thimble type' filter just inside the fuel in connection and its a right b**d to clean ... how do I know ? It happened to me ..... ).

So tank is emptied / treated ..... pipes are clear .. filters changed.

Back to fuel. I'm a cheapskate and will not throw away fuel ... so I will decant settled fuel to another set of containers .... another dose of Biocide .. let settle again. If you have a filter (coffee filter in a funnel will do) ... then you could carefully pour through ... changing filter often ...

Leave this old fuel to one side and next step use fresh clean fuel ....

New fresh fuel - give it a good dose of Biocide and then pour into your tank. Bleed - prime system ..... start engine. Once you know engine runs OK ..... you can then think about that old fuel.

By now Biocide should have done its work ... so carefully decanting off the fuel leaving crud behind ... you can mix with fresh fuel and into tank. The Biocide should take care for you.

Now that engine and system is operable again ... its a good idea to add a dose of Biocide every so often just to keep things clear. You will NEVER cure or stop Bug ... all you can do is CONTROL it.

Fuel is my business .... so I might have a bit of a clue about it ....

That valve...... you really need to get that sorted while tank is empty etc.

 

[ylop]

Back to fuel. I'm a cheapskate and will not throw away fuel .

If you really only have a few litres I'd get rid of it - a single organism surviving (or worse being resistant to your biocide) will start the whole cycle again! 100L is different because of both its value and the difficulty in disposal. 10L or less I wouldn't waste my time.

Polishing just removes the gunge - which can be removed without ....

And then you describe polishing it with coffee filters!

I looked up biocide. I ordered some now. Plan of action: suck up water from the bottom of the tank (no drain due to access or lack thereof), dump biocide into it, wait a couple of days for it to do it's magic, replace primary filter (secondary already changed), hoping it will allow the diesel to flow again. If it does, run engine often, keep treating the diesel, change the filters again soon and that should be it.

I really wish I could clean the tank though.

If its bad enough to block pipes/valves do it properly, or you'll be doing it forever.

 

[Refueler]

If you really only have a few litres I'd get rid of it - a single organism surviving (or worse being resistant to your biocide) will start the whole cycle again! 100L is different because of both its value and the difficulty in disposal. 10L or less I wouldn't waste my time.

I'm talking generally .... of course if its just a litre or so ... use it on the bonfire.

And then you describe polishing it with coffee filters!

Bit different to what some describe - pumps / pipes / filters etc.
The coffee filter is just to remove and crud that doesn't settle.

If its bad enough to block pipes/valves do it properly, or you'll be doing it forever.

Are you saying I don't know ?? Maybe read whole post and if followed steps ... most instances of Bug can be controlled. As I already said - Bug cannot be cured - it can only be controlled. You kill and then next fuel fill .... its back again.

But what do I know ? I only look after thousands of tons of the stuff ... owned / set up Petro Labs .... own Petrochem Inspection Co. ..... supplied hundreds of tons additives to Oil Industry ...

 

[ylop]

Are you saying I don't know ?? Maybe read whole post and if followed steps ...

eh, before you go in a strop perhaps read the quote - I wasn’t replying to you I was replying to the OP essentially emphasising your advice. He is proposing biocide and hope! His original post read at first like it was just running a bit rough and fuel discoloured but I’ve reread it and I think he’s saying no fuel getting through at all - he’ll never fix that properly just with chemicals.

 

[DangerousPirate]

eh, before you go in a strop perhaps read the quote - I wasn’t replying to you I was replying to the OP essentially emphasising your advice. He is proposing biocide and hope! His original post read at first like it was just running a bit rough and fuel discoloured but I’ve reread it and I think he’s saying no fuel getting through at all - he’ll never fix that properly just with chemicals.

Yeah, indeed. No fuel is coming through at all in the end. While I worked on it it got gradually worse over the course of a day.

These bacteria always live in the diesel. They only can be controlled (never eradicated). So I figure once I got it running I'll just make sure that the tank is always filled up and no water is inside, monthly drain the water from now on.

FYI: I ordered Beta16 Diesel Bug Treatment, after carefully selecting it based on the PBO test.

This is a quick fix for now. The debris can be filtered out, the problem seems to be the slime that clocks stuff up. But that's the bacteria, once it's dead it's not slimey anymore (according to pbo). Hence the "spray and pray".

Look. i have to work with what I have. If the Tank doesnt come out, I will have to do my best with it staying inside. I can blow air back into the tank, pump the diesel out and try to suck up as much residue as possible, but I can't get the tank out without getting the engine out. I can't do this before I am somewhere proper.

 

[ylop]

If the Tank doesnt come out, I will have to do my best with it staying inside. I can blow air back into the tank, pump the diesel out and try to suck up as much residue as possible, but I can't get the tank out without getting the engine out.

I would expect that between the fuel filler and the fuel pick-up pipe you have options that you can use without ripping the tank out. Baby bottle brush on an extension. garden sprayers etc might be able to reach parts you can't of filling and rocking the boat to work around baffles etc. Make sure you get it as dry as possible afterwards - there are "socks" with desiccant in them designed to be inserted via the filler cap (make sure it can't block the pick up).

PS - the most common, really problematic contaminant is not actually a bacteria its a funghi.

 

[DangerousPirate]

I would expect that between the fuel filler and the fuel pick-up pipe you have options that you can use without ripping the tank out. Baby bottle brush on an extension. garden sprayers etc might be able to reach parts you can't of filling and rocking the boat to work around baffles etc. Make sure you get it as dry as possible afterwards - there are "socks" with desiccant in them designed to be inserted via the filler cap (make sure it can't block the pick up).

PS - the most common, really problematic contaminant is not actually a bacteria its a funghi.

Funghi? But the filter was slimey and there was water in the fuel, ut also looked Brown. Do you know how to identify that funghi?

 

[ylop]

Funghi? But the filter was slimey and there was water in the fuel, ut also looked Brown. Do you know how to identify that funghi?

What is Microbial fuel contamination? - Conidia Bioscience

 

[DangerousPirate]

What is Microbial fuel contamination? - Conidia Bioscience

I think that's the diesel bug, but in other words. But thank you for the informative link.

I found this link: How to Clean a Boat Gas Tank Without Removing It - 4 Simple Steps

And maybe try this. Really annoying that I can't get the tank out.

 

[Poey50]

I had a bad dose of bug that came free with the boat on purchase in 2016 since she hadn't been used for about 18 months. Our tank is also very tricky to move so I haven't!

I built a fuel polisher and use this at the start and end of every season. I also dose every batch with Marine 16 and am scrupulous about sealing the fuel cap threads with soft grease to avoid water getting in. Tank condensation has been demonstrated to be a myth so I don't bother filling before layup. I've never had any problem since.

 

[DangerousPirate]

I had a bad dose of bug that came free with the boat on purchase in 2016 since she hadn't been used for about 18 months. Our tank is also very tricky to move so I haven't!

I built a fuel polisher and use this at the start and end of every season. I also dose every batch with Marine 16 and am scrupulous about sealing the fuel cap threads with soft grease to avoid water getting in. Tank condensation has been demonstrated to be a myth so I don't bother filling before layup. I've never had any problem since.

Did you just polish the fuel? Or how did you clean your tank?

 

[Kukri]

Here’s my thread on my diesel bug:

What lurks beneath…

 

[Poey50]

Did you just polish the fuel? Or how did you clean your tank?

Tank cleaning goes with theory that you can and should eliminate the bug. I think that's unrealistic and the alternative is to accept that some bug is always there waiting to bloom if water gets in or biocide is forgotten. As said, I've not had a problem in the 6 seasons since using this method. I've never seen any water or bug in the plastic reservoir below the filter, for example.

 

[DangerousPirate]

Here’s my thread on my diesel bug:

What lurks beneath…

Sounds good, if you can access the tank like that. Unfortunately my tank is behind the engine and there is only one opening on top, and that is to fill the diesel. Not the best design, but I never would have thought this would be such an issue.

Not sure if it's standard on the nicholson thirty, but beta engine was fitter some point later, so I suspect they did the tank at the same time.

https://imgur.com/yRVbbBY

See the tank in the background. Ugh.

I would get a professional, but I don't want anyone to cut my entire boat open just to get the tank out or something?.

Not sure about order of things now. Guess I'll just dump the biocide in there, wait a week, empty the tank, blow air through the hose to clean it, clean the tank with the method from the pbo article, change filter, and then tank it up and see if it runs.

Or maybe I should use the hose and instead of blowing air through it, I should suck it all out with a pump, the diesel and the funghi? Not sure if thats better. Because the main issue is that nothing comes through at all right now. This way I'd get rid of some of the gunk already before cleaning the tank and initiate further steps.

 

[Refueler]

eh, before you go in a strop perhaps read the quote - I wasn’t replying to you I was replying to the OP essentially emphasising your advice. He is proposing biocide and hope! His original post read at first like it was just running a bit rough and fuel discoloured but I’ve reread it and I think he’s saying no fuel getting through at all - he’ll never fix that properly just with chemicals.

Not in a strop ... far from it in fact ...

My Post made point of blowing through lines etc. Once all fuel system is clear ... then a decent biocide treatment will break down any crud that is not 'vacuumed out' / settled in containers ... even any moisture left - which dead bug is like a sponge for.

I'm not so happy about this valve he mentions .... not unknown for valves to fail internally and lead to starvation. Also if tank is with plenty crud ... fuel pick-up can lead to intermittent / unreliable running .. eventually blocked lines.