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!!!

 

[gaz_123]

UPDATE this brown stuff is now being tested as this was in march and all 4 injectors were shot and had to be replaced and a whole system flush with new fuel filter, all was and still is running perfect however 6 weeks later flashing coil light and p0087 low fuel pressure code came up. Since then i have had a new fuel rail sensor, no luck still the code cane back, and yesterday a new hpfp was fitted even though no signs of wear or swarf we bit the bullet as the code flagged up it intermittently lost 300-500 bar of pressure each time. So even after a new hpfp the van drives better then ever before however 165 miles in the code has flashed back up! Next steps is fuel rail and regulator and im hoping its one of them as everything then apart from the lift pump has been replaced. Anyone else had this or am i best to replace the lift pump first before the rail and regulator as this has already cost me £4.5k!!

 

[gaz_123]

Also still have the brown fuel from the above pics so we are just going to get it tested for the sake of it, another £20 for testing wont hurt when I've already spent £4.5k however testing after the flush and new injectors all came back clear so im hoping its all out the system now anyway but wont hurt knowing what it was in the first place!

 

[The Flying Scotsman]

Also still have the brown fuel from the above pics so we are just going to get it tested for the sake of it, another £20 for testing wont hurt when I've already spent £4.5k however testing after the flush and new injectors all came back clear so im hoping its all out the system now anyway but wont hurt knowing what it was in the first place!

This might be of use

Pardon our interruption...

 

[Sasquatch]

It'll be most interesting indeed to see what it is.

 

[gaz_123]

UPDATE - the whole of the fuel system has been replaced including the fuel tank, lpfp, hpfp, fuel rail, fuel regulator, fuel pressure sensor, fuel filter, all 4 injectors due to fuel contamination and swarf being present in fuel tank and still the p0087 code! Scan is still showing 300-400 loss in fuel pressure however van drives perfect, seems to throw the fault code every 150 miles when going around 60-70mph. The van was remapped prior to our ownership so unsure how well thats been done so at this monent in time the remap is being reversed back to factory settings, fingers crossed as we are £6.6k down and still no solution!!

 

[DXX]

Cheap, instant and well proven method for determining water contamination of fuels and lubricants.

 

[manfrotto]

Did you get the contaminated diesel tested, and what was the result?

 

[gaz_123]

Did you get the contaminated diesel tested, and what was the result?

Water but its been in there a long time way before we bought the van by the looks of it, replaced everything now just cant get rid of the code coming up every 100miles, scanner still says its lost between 300-400 in fuel pressure so god knows

 

[Kind of Blue]

Most likely the water came from a contaminated fuel bunker at some time. For many years I have used supermarket fuel without issue. I was once many years ago told by a taker driver that fuel that is in the tankers from refineries is all the same. The main differences are that some outlet have different additives added as they deliver. Supermarkets have specific additives and they check that is what they get He said that supermarkets are very strict on what is delivered to them, that their tanks are frequently checked and their their tanks are the least likely of any to have water ingress or any other containment. Most likely source of water or other contaminant is from small garages and fuel stations that do few checks. The only time I had contaminated fuel was from a small outlet so I prefer supermarket fuel or very busy and heavily used fuel stations.

 

[gaz_123]

*UPDATE* so after replacing the whole fuel systems including the tank the code still resurfaces so couple of weeks ago had the remap reversed (was done before we bought the van 150bhp to 180bhp) drove even better then before less agressive in the revs but no obvious loss in power just a smoother rev count - got 300miles and light came back on code p0087 still. Drove to devon on holiday absolutely perfect except when we tried
To go up a steep hill. Light came back on but now 2 codes appeared P0087 low fuel pressure and also p0562 low voltage! In the past 6 months we have also had this accompany the p0087 code but not everythine and not for a while. Battery and alternator seems fine apart from if we leave the battery a day it goes down to 12.1v so unsure if its a sign of a weak battery or alternator. Vans back in the garage next week to check out the wiring and alternator - wish us luck hopefully we have found the trigger

 

[DXX]

*UPDATE* so after replacing the whole fuel systems including the tank the code still resurfaces so couple of weeks ago had the remap reversed (was done before we bought the van 150bhp to 180bhp) drove even better then before less agressive in the revs but no obvious loss in power just a smoother rev count - got 300miles and light came back on code p0087 still. Drove to devon on holiday absolutely perfect except when we tried
To go up a steep hill. Light came back on but now 2 codes appeared P0087 low fuel pressure and also p0562 low voltage! In the past 6 months we have also had this accompany the p0087 code but not everythine and not for a while. Battery and alternator seems fine apart from if we leave the battery a day it goes down to 12.1v so unsure if its a sign of a weak battery or alternator. Vans back in the garage next week to check out the wiring and alternator - wish us luck hopefully we have found the trigger

If you have a 12v Cig socket > USB adapter with a digital display or a multimeter you can read the alternator voltage with the engine running to prove the alternator.
If the socket voltage is good once the battery is fully charged the alternator is good.
Check for a corroded or loose engine earth strap and or poor battery connections.
If the battery has been discharged very low below 50% SOC (around 12.05V) and/or is 5 years + old it is probably knackered, even if the charged battery voltage is reading 12.6 it may not take a load.
You could visit a battery specialist and have it load tested or you could just replace it if you know it has been repeatedly discharged below 50% SOC and/or is 5+ years old.