We had a boat with a 80hp Perkins diesel motor. Once we had a build up of a horrible seaweedy gunk that grew in the fuel tank and it was very difficult to clean out.
To prevent that happening again we had to add a small amount of an additive each time we filled the tank.
Does that happen in vehicles as well?
Our motor home does get left for periods of say 2 or 3 months at a time, and I was worried that we may need to start using an additive.
Any advice?

Hi, I don't have any advice on your topic
for the Ducato. As my other diesel is a Hyundai I have friends who add a litter of petrol to each tank. I am not game to try!

I have a question though but I can't seem to find how to start a new topic. I have a Comfortmatic gearbox on my 2012 ducato and I can't find the fuse box for f26 and f27. Some say it is a separate fuse box behind the main fuse box in the engine bay. I can't for the life of me find it. Help. do you have to remove the headlamp LHS?

Yes. Can happen if left long enough. If in doubt, an additive will give you peace of mind.

I have exactly the same thoughts as the original poster, for the same reasons. I use fuel preserver in my classic bikes, not because of fungal growths, as its petrol obviously, but to limit damage cuased to fuel systems by modern unleaded fuel, which soon degrades, but worse, causes severe depoits and corrosion and will kill steel tanks etc. easily.

I just search ebay for diesel fuel preservative, from time to time, and gogole too- results are not always as informative as I woukld like.

It DOES seem to be a good idea, just in case modern low sulphur diesel has adverse effects as per petrol.

Seems to me, the trick is to find one that claims to do what is needed, at a sensible price, mostly they seem to be American products. I will follow this one! Cheers.

I use Hydra Fuel Plus Multi Biocide additive in a full tank when the van is parked up for any length of time over the winter. It's a UK product and a little goes a long way as a preventative measure. I haven't suffered from diesel bug so can't vouch for its effectiveness as a bug remover, but possibly that is a recommendation in itself.

https://www.hydra-fueladditives.com/

Any air above the fuel in the tank contains some moisture. As the temperature changes, it condenses on the sides of the tank, where it can attract microbial organisms, that grow. Over a prolonged period, the tank breathes as pressure changes, allowing more air in with more moisture, and the larger droplets then drain down, to the bottom of the tank. This is why the fuel filter usually has a water trap and drain tap. The water can also freeze in winter.
Many truck drivers always try to leave the tank full overnight, especially in the winter. Less air, means less condensation.
When leaving the camper for any period, you could try to leave it with the tank full, but also add some biocide as suggested above.

Or try to use it more regularly, just to keep it running. Although a bit of a pain commuting or shopping.

I leave my van for 6 months over the winter unused, never had a problem.

But it can't harm adding a preservative, but 2 or 3 months unused isn't really very long.

Most fuel tanks are plastic these days which will help minimise any water build caused by condensation.....the bugs live in the fuel / water layer.

Got a yacht too ( that hasn't been used in 5 years as i bought a motorhome and prefer it to sailing in the UK !! ) with 65 Ford FSD engine and generally did put an additive in that as previously it was always laid up for 7 months.

Friend has an SP Cruiser....he never uses an additive but always fills his tank up at the end of the season......nearly a 1000 litre tank....glad I'm not filling that one.

Yes i wil strongly advise to do so, specialy with standing vehicles like motorhomes !
Until 15years ago i was also unknow with the dieselpest(a german word) as a mechanic.

Actualy i am very cynical to most preventive oil and fuel aditives!!


But since then it happens regular,and it is nasty and expensive!
The bio content and water in diesel do promote the grow of algae/fungy in tanks.

And it is NOT ONLY with STANDING vehicles.
A friend of us is a national salesman and drives his citroen c5 diesel every day.
He drives at least over 40.000 miles a year .His car does not stand still .( les than 2 weeks a year).
At about 100.000 miles he came to a stand still,and had a cleaning and repair bill
from over 3500 pounds on his fuelsystem....
He put in a claim with his fuel suplyer,wich was only marginal rewarded...
(but in a small regional depot they stocked over close to 1000 gallon of antialgae/fungy he found out)And THATS A LOT OF BIOCIDE for a small depot we think..

I learned my lesson;Fill up for stand still with WINTERdiesel against parrafine in low temp. And add BIOCIDE all year against ALGAE/FUNGY!
This was the worst and clearest case in my 40years experience as mechanic in diesel powered engines...

But adding ethanol to fuel is a GREEN rage, and ALGAE are named as source of fuel of the future....Last word on the subject is not spoken yet........
kind regards ben

Fuel suppliers like BP tell us that any additives at all are a waste of money and time and can even be harmful, as their fuels are added to with everything necessary in correct proportions. And they vary things according to time of year and geographical location, so the diesel you buy in the North Cape is suitable for use there, as is that which I buy suitable for use here in Almeria. Diesel however does go 'stale' especially in marine environments, when you should pump out the tank if it is to be unused for a lengthy period, and use it up in your car perhaps, then when you want the caravan again fill up with fresh diesel.