Brown liquid in my diesel! What is it?

[gaz_123]

Was having issues with my T6, loud lumpy starts, ticking when cold, stalling etc. had it inspected and the fuel tank was full but in the diesel was a strange brown liquid, wasnt swarf, wasnt sludge just a brown liquid that when you shake it it doesnt mix just sits at the bottom whilst the diesel sits on top. Garage has never seen anything like it before and has ruled out diesel bug as it isnt thick. Anyone have an idea or seen anything like this before?

 

[Drifterman]

Looks very similar to something I saw years ago - somebody put sugar in a fuel tank…..the guy had upset somebody and they were sneakily trying to get revenge

 

[manfrotto]

My first thought was bug, but it sounds like you have ruled that out already. It is not just water?

 

[Turboponzy]

Looks like water, we have water separators on our tractors and when they’re full it looks just like that.

 

[Badjamin]

Water was my first assumption. Have you had your tank flushed clear?

 

[BiTurbo]

It’s the biofuel that has separated from the diesel.

Petrol, diesel, biofuel, autogas. Here's an overview of different fuel types!

The fuel labels have changed, and it can be difficult to navigate the landscape of fuel types. Read more here.

www.autobutler.co.uk

It’s common if your van stands a lot. Using cheaper supermarket fuel. Refilling at less than empty.
We had company cars at work that only used supermarket fuel, refilled at 1/4 tank. Tanks full of bio gel, blocked the fuel lines starve the high pressure fuel pump and put metal into the injectors.

Resulting in new tank, sender, fuel pump lines, HPFP, and injectors. Irc the bill was around £4k each.

I would suggest removing the tank, back blowing the fuel lines from filter to tank and washing the tank out throughout.
Then only buy quality fuel like V power.

 

[Dellmassive]

Dirty rusty water from condensation in the Petrol station tank?

 

[Sasquatch]

It's clearly more dense than the fuel, so water contamination seems likely.

Contrary to popular belief supermarket fuel is generally - but not exclusively- a safer bet in this regard. They're usually busy forecourts so tanks aren't left low or empty for long, giving less opportunity for contamination by condensation.

Or an older tank can allow the ingress of surface water through poor design or inadequate maintenance. Again, less likely to be an issue with the typically more modern supermarket forecourt.

Diesel itself carries inherently more H2O than petrol, hence the fuel filter acting as a water separator. Nevertheless, that looks more like contaminated fuel.

I presume any fittings at rhe top of the tank, lift pump, sender, etc, aremsecure and not allowing water in? Probably not but worth a look.

 

[koolpc]

Dont pee in the fuel filler!!! For goodness sake!!!