Black diesel....

JohnCleary

I have a large tank which I normally store my diesel in, of which I had left about 60l in over the winter (I know, I know I should have had it full as it's a stainless tank, condensation etc. but too much worry about theft etc.)

Anyhow, decided to test this bit that was left in it, and it's turned black? Filter in the tank (between the feed and the pump) is clean... is there something up with this remainder of diesel and is it safe to put a fresh batch of fuel in on top of it??

BTW it's green diesel, used for non road going veichles

Would appreciate your opinion

JohnCleary

Just been informed on aonther forum that i've got the bug (bugger!) - going to drain out what's left, clean out the tank and replace filters

biko

Eating diesel urrg

The bug is a living organism which occurs within diesel tanks - when a diesel tank is left standing half empty, the empty part will 'sweat' when there are significant fluctuations in temperature in a damp atmosphere. This water falls to the bottom of the diesel tank and creates a layer at the bottom of the tank - it is here between the diesel and the water that the bug occurs. The bug feeds off the diesel, and eventually turns it to a black jelly which is accompanied by a distinctive foul smell. Once the engine is started, the jelly gets dragged through the fuel system and blocks up the fuel lines, filters, lift pump, injectors and fuel / injector pumps. Once it has gone this far the only cure is to remove all the parts, steam clean them all and replace them before even attempting to start the engine again.

http://www.3cbcvm.org.uk/mag_arch_aut04.html#bug

Darragh29

That's amazing information. I remember I had a customer with a Rexton jeep and I was servicing it one day for him and when I removed the fuel filter, the diesel was pure black, like as if it had been sitting in a bucket of coal for a week! As it happened the engine had running problems that were quickly tied down to the black diesel. He happened to live near the border so I just put it down to poor quality or laundered diesel, but this would seem to explain the problem....

JohnCleary

Well aware what the bug is but thanks all the same for doing some research

All sorted now, tank dry as a bone filter elements replaced and filter bowl cleaned.... I could have polished/treated it but for the amount of diesel (about 60l) it wasn't worth it just got rid of the feckin stuff

CJhaughey

Might be no harm to get some fuel treatment to stick in the first load of diesel to make sure any remaining bug is killed off.

peasant

Darragh29 wrote: »

That's amazing information. I remember I had a customer with a Rexton jeep and I was servicing it one day for him and when I removed the fuel filter, the diesel was pure black, like as if it had been sitting in a bucket of coal for a week! As it happened the engine had running problems that were quickly tied down to the black diesel. He happened to live near the border so I just put it down to poor quality or laundered diesel, but this would seem to explain the problem....

quite a common occurence in the pleasure boat and RV world, where vehicles lie idle for prolonged periods of time

http://www.oillab.co.nz/diesel_bug_explained

GTE

CJhaughey wrote: »

Might be no harm to get some fuel treatment to stick in the first load of diesel to make sure any remaining bug is killed off.

Do those off the shelf additives and treatments actually do anything?
The shop i work in has loads but Im unsure if they are merely a gimmick

JohnCleary

bbk wrote: »

Do those off the shelf additives and treatments actually do anything?
The shop i work in has loads but Im unsure if they are merely a gimmick

Yup, very good idea and plan on doing it

CJhaughey wrote: »

Might be no harm to get some fuel treatment to stick in the first load of diesel to make sure any remaining bug is killed off.

Few boaty people I know swear by it in the sense that they use a little bit and have never gotten the bug (some cruisers may only fill up once/twice a year)