Diesel worm

[galeus]

For the last 2 years I have been dosing (normal dose) my diesel tank with Grotamar 82.
I've been having the engine etc. serviced and the news back from my trusty friend and mechanic is we have diesel worm.
We needed a new gasket for the top of the fuel tank and it was plain to see on the sender unit mechanism as well as the banjo joints to the fuel lines and in the primary fuel filter.
He also advised me that the Grotamar 82 is for diesel inc. biodiesel, which he reckons is not the case at the marina (here in Tenerife) as he thinks there is no biodiesel inc , so is ineffective in dealing with my problem.
He put in a shock dose of some product called Agri (something or other) and reckoned that was the way to go and look at everything again in 10/12 hours.
Anybody any thoughts please.

 

[Bandit]

By normal dose I assume you are talking 1 litre Grotamar 82 to 4000 of Diesel.

I assume by "worm" you are referring to diesel bug?

Grotamar 82 is suitable for diesel, biodiesel and low sulphur diesel, see https://echamicrobiology.com/products/biocides/grotamar-82

Grotamar 82 is a biocide and if when you started using it there was contamination in the tank, Grotamar 82 will kill the bug but not remove the dead slime, it will break upa and remain in your tank until collected by a fuel filter.

If you have the inspection plate off I would now clean the fuel and the fuel tank and remove any water in the tank which build up over time.

 

[Hurricane]

By normal dose I assume you are talking 1 litre Grotamar 82 to 4000 of Diesel.

I assume by "worm" you are referring to diesel bug?

Grotamar 82 is suitable for diesel, biodiesel and low sulphur diesel, see https://echamicrobiology.com/products/biocides/grotamar-82

Grotamar 82 is a biocide and if when you started using it there was contamination in the tank, Grotamar 82 will kill the bug but not remove the dead slime, it will break upa and remain in your tank until collected by a fuel filter.

If you have the inspection plate off I would now clean the fuel and the fuel tank and remove any water in the tank which build up over time.

Agreed
After having had the bug, we use Marine 16 which I believe is very similar to Grotamar.
When we had the bug, I did a test.
I took about a gallon (in one of those water containers you get from the supermarket) of black sludgy fuel from the bottom of our tanks and mixed in some Marine 16 - shook it all up and left it overnight.
In the morning all the black stuff had gone so I thknk it would also get rid of the slime inside the tanks.

 

[galeus]

Unfortunately the boat is back in the water, so cleaning the fuel will be difficult, but taking heart from Hurricanes test.
I think diesel bug and worm must mean the same; having looked at it in the old primary filter, it is wormish, about 1/4 inch long.
I did dose it at the regular preventative dose Bandit, not the shock dose, but I don't have the bottle to hand to know the ratio.
That was before the previous service and no mention was made of the problem then, so I presume it has happened after the initial dose.
The boat next to me has the same problem affecting both engines and I know of others. Complaints have been made to the Port authorities
about the fuel they are probably dispensing, but falling on deaf ears.
Feeling a bit tentative about going far at the moment, went out today for about 2 hours fishing but stayed in a radius of about 3 miles.

 

[Powersalt]

Agree with what was said on past threads. I had a similar problem and after much discussion with marine engineers and the Marin 16 treatment company came up with a solution which work out well for me.

First get Marine 16 and forget about dosage just put a bottle in each tank and leave for 48 hours. After 48 hours drain off from the bottom of the tank until no water is there. Keep a sample for reference. Buy about 3/4 sets of pre filters and learn how to change them. This will give you safety at sea as well.

The diesel bug should be killed ok, but left in the tank. But here is the interesting bit, if you continue to dose at lower levels over a period of and use of engines, it will clear all particles. For me I would not go for more than circa 2/ 3 hour trips at a time checking filters before and on return . every few weeks drain the bottom of the tank and see if it is improving quality of fuel. Hopefully you have glass bowl for pre filter. It worked for me and after the season there was no trace in tank or filters. good luck

 

[A1Sailor]

It might be worth finding out what is in the bottom of your tank. Here's what was in mine:

If you have a Pila extractor you can stick the "wand" into the tank and sample from the bottom.

 

[Bandit]

You need to clean the tank, crud and water will not just go away.

Grotamar 82 preventative dose 1 litre treats 4000 of diesel
Shock dose one litre treats 800 from memory.

 

[QBhoy]

Believe it or not, on a number of cases, dosing the tanks causes more problems. It tends to release all sorts of passive (and not generally a current problem) crap in the tanks and lines and put it straight into the filter and causing blockage or starvation.
Just a thought.

 

[Bouba]

Believe it or not, on a number of cases, dosing the tanks causes more problems. It tends to release all sorts of passive (and not generally a current problem) crap in the tanks and lines and put it straight into the filter and causing blockage or starvation.
Just a thought.

This is not what I wanted to hear

 

[QBhoy]

Oops. Sorry...haha.
Not always, but sometimes.
In my opinion, unless you have a real and current show stopping problem with diesel bug....fuel level management and good separating pre-filter (with regular draining) is the best way forward. Oh...and always keep a spare set of filters and be careful of taking on fuel from a marina storage tank at a low level.
Also try and keep the engine room (if tanks are in that space) at a controlled and stable temperature during winter storage, if you can't manage totally empty tanks or full tanks during this period...

 

[Bandit]

Clean your tanks and fuel system.
Remove all water, without water bug will not grow.
Always use a Biocide such as Grotamar 82.
Regularly inspect your fuel system and take appropriate action.

Always carry three sets of spare fuel filters, if you have to change the pre filters, its about the only thing you can do at sea.

 

[superheat6k]

Filtration, Filtration, Polishing, Filtration.

Did I mention Filtration ?

Fuel set worthwhile for getting rid of water as it absorbs it into the fuel, burning it off rather than killing the bugs. It is the dead bugs that block the filters.