Technical Gelled Diesel - LP pump now sounds like a coffee grinder!

[Matt Quinn]

So... Monday (the 27th of November) and all was well. Temp hovering about/above 0c - no real issues starting. By Friday the 1st we'd had a couple of nights circa -5c.

My 2013 Qubo (Diesel) isn't used much; the last time it was fuelled up (from about 1/3rd of a tank to full) was October 14th; the time before that probably late August or September ...So possibly not a winter diesel mix at all and at best a summer/weak winter mix.

It now has about 1/3rd of a tank of 'that stuff' left... Friday; -2c and it's a no-start; we'd had -5c overnight! My battery has also been 'suspect' as I've been getting the dreaded 'hill holder' message for months; but it was turning over OK 'till I flattened it.

Brand new battery ordered and arrived yesterday; topped up to 13.2V so very healthy... Fitted this morning and the winter woes just go on and on...

The LP fuel lift pump (under the seat) now sounds like a coffee grinder; actually this was evident before I turned the engine over - and hadn't been the case on Friday when I gave up trying to start. But then the rest of Friday and yesterday were well below 0c. - My 'guess' is the fuel is now badly gelled and it's not pumping 'liquid' (or possibly anything at all). And of course, despite the fact the engine now spins over like a mad thing, it still won't start!

I've tried gently warming the fuel filter and even the plate above the tank - but we're still in coffee grinder territory; and if the pump isn't dead (or fatally injured) already, carrying on like that will obviously do no good to anything...

We've been sitting around the 0c-1c, maybe +2c at the warmest part of today - so I'd imagine that if the fuel has gelled there is little or no possibility of it liquefying again in these conditions. Prospects seem to be for a short period of +2c, 3c, 4c, tomorrow (Monday) into Tuesday; but I'm not convinced that will be warm enough to resolve matters. ...Where the car is sitting, there is no possibility of getting mains power to it to run a fan heater under it, or the like.

So.... Opinions please. Do I cut to the chase now and just order up a new LP pump? Is it inevitably creme-crackered after this abuse? Or might it be OK once 'thawed'; anyone have any experience of this sort of situation?

Is there any sort of tutorial or instruction page out there on how to replace it (no I've not removed the cover plate yet to look); I have a pretty good set of car tools, but is there anything 'odd' needed to get it out and re-fit?

- Fuel filter; may as well get one anyway - looks easy-ish; but any advice (even basic) would be welcome; I assume the sensor block on the bottom just unscrews and it re-fitted to the replacement? Or do replacements have blocks already fitted - they don't look as though they do from what I can see in pictures. - What about the bleeding bleeding procedure? Quick twist of the nut on top or - something else?

Obviously the first thing I'll do (once we're running) is take it to the filling station and get some fresh diesel... If I were in the states or Canada I could probably obtain some chemical that would do the job; but not here (in the UK) it seems! - Any input from the amateur alchemist community would be appreciated.

In fact, all thoughts on the problem (even daft ones) and how to solve it will be most welcomed...

 

[varesecrazy]

Hi

A couple of pointers..
There will be several options for Brand of Filter

The brand may well have it own fitting method

You Could buy a winter diesel additive.. I had mine 20 years ago
STP/WYNNS, etc

A cheap and easy option is a few litres of paraffin..

Not as good a lubricant.. As its thinner

But safely combusts alongside diesel

 

[Matt Quinn]

Many thanks for the response.

...Not actually sure where I'd get paraffin to be honest; it's many decades since I last saw one of those dispenser machine things that filled a gallon tin for ten bob. - The stuff of childhood trauma; being sent round to the local garage on a cold day with metal cans that chewed into your fingers.

All the winter additives I've looked at (online) say they need to be added before the wax has formed. - There seem to be a very limited amount on the UK market too. About the only 'old school' suggestion I've come across so far is adding some 99% Isopropyl alcohol; which oddly enough I do have as it's used in my work. - So about 200ml in what I'm guessing is maybe 20l of Diesel; added that this afternoon. ...Of course, if that works at all as a 'de-gelling agent' it will take time as it would need to diffuse through the fuel; there being no way of agitating it.

Time - I suppose - will tell. I'll take another look at it tomorrow... actually take the plate off the floor and see what the top of the sender looks like.

Somebody suggested kettles of boiling water poured over the top of the tank and the filter casing; I've heard worse ideas I suppose. - I assume that both will be pretty resistant to water ingress. Once it's running, adding proper winter-grade fuel will, I think, solve the problem. The worst of all this is that it's not really all that cold! -10c is often seen during the real depths of winter. - And even summer diesel is supposed to be OK at -4c.

 

[chris3234]

I didn't think winter and summer diesel mix had been a thing for many years
Refining has improved since the early day's

And UK temp don't warrant a different mix for the winter temps

 

[varesecrazy]

I didn't think winter and summer diesel mix had been a thing for many years
Refining has improved since the early day's

And UK temp don't warrant a different mix for the winter temps

According to Crown Oils their diesel is:
- 4 in summer and - 12 in winter

Stock swaps 15th November and 15th March

 

[Matt Quinn]

I didn't think winter and summer diesel mix had been a thing for many years
Refining has improved since the early day's

And UK temp don't warrant a different mix for the winter temps

It depends where in the UK you are... I've seen -18c (in the past) from the garden thermometer here in a village, just to the west of Edinburgh. It can get much colder further north. ...Chemistry is chemistry; the alleged -4c resistance quoted for summer fuel probably is the improvement from the days when it was common to see small fires deliberately lit under Taxis and Lorries of a winter's morning! - And no; I'm not trying that!

Anti-gelling agents will tend to reduce the Cetane level of the fuel; so make consumption worse - and probably harm the emissions performance. - And of course cost money/eat into profits.

So... Kettle of hot water over the top of the tank... anyone got any thoughts on that one? Is it a really stupid (and inadvisable) idea or just plain just ordinary-stupid? - And what about the coffee grinder? Any thoughts on that one?

 

[portland_bill]

When diesel fule gets cold, it starts to separate out, making waxy particles. These block the fuel lines, prevent pumps running, and struggle to pass through injectors.

A kettle of hot water over the tank may help, although the heat loss to a cold tank would need more than a kettleful. Paraffin is still used, mostly for greenhouses, so DIY and garden centres sell it. Adding 2-5 litres of paraffin will help dissolve the waxy particles again, in the tank, but will not run easily through the pipes.

Ideally you need to remove the fuel in the pipes, from tank to injectors. Quite a task, crawling underneath in the cold. Once the pipes are empty, you can add paraffin to the tank, and bleed it through.

Years ago, many diesel owners, usually trucks and vans, would park their vehicles in garages overnight, with a small paraffin heater under the tank. Like a greenhouse heater. Won't work well outside sadly.

Fuel tanks suffer from internal condensation. The air above the fuel contains moisture, which condenses on the walls of the tank on a cool night, then runs down. The water sinks to the bottom, ready to be first through the pipes. In regular running, this is separated by the fuel filter, which is why they usually have a drain on them. Modern diesels will pop a warning light if the water content in the filter hits max. You could have too uch water in the pipes. Many fleet operators will top the fuel tanks each night, to reduce condensation, as no air, means no moisture. Leaving the vehicle unused with less than a full tank promotes condensation. Thisis also a problem with petrol vehicles, but they cope better, as the fuel readily combusts at very low temperatures.

See if you can drain the pipes.
You might try eezi-start or similar. Once it fires, it might continue with the poor fuel, allowing the paraffin mix to come through, then all may be well.
With paraffin, the exhaust will smell different. I, sadly, can detect a paraffin burner from some distance. This may get the attention of the police or DVSA, but armed with your half-used pot of paraffin, and your story, they should accept that you are not using it to avoid paying the revenue on the diesel fuel. There used to be a maximum recommended mix ratio, you'll need to look that up. Paraffin is a short-term fix, due to its reduced lubrication properties, as said above.

 

[portland_bill]

Just a thought. Have you been using old veg oil mixed in? That tends to separate out, and form jelly. Done properly, additives are included to keep them mixed.

 

[Matt Quinn]

Thanks for that Bill... No kind of veg mixture; just standard fuel. I used to use both Straight Vegetable Oil and BioDiesel (from Apple fuels in Glasgow) in my old Isuzu Bighorn; but then it had a pump that would do that. The Qubo seems 'too wee and fragile' a thing for that sort of 'abuse'. And TBH I'm not doing anything remotely like the mileage to justify it. ...The last lot came from Sainsbury's in Dundee on October 14th; so probably still 'summer' stock and probably not the most extensive additive pack in it either.

I've always worked based from home (I'm a cameraman by trade) but since the pandemic ill-health has kept me more desk-bound (editing etc.) which is why the car isn't getting used much. And, actually why I no longer run a large 4x4; something I'm beginning to regret slightly.


Generally speaking, we don't see a snap as cold at this until after the new year...

 

[varesecrazy]

Worth while looking at your diesel filter

IF.. you can dismount it..
Drain it to gauge the state of that Sainsbury fuel,

Then refill with the derv parrafin mix, it should then run acceptably.. Even for a couple of minutes

 

[Matt Quinn]

So... reluctantly-enforced-holiday snaps firstly the filter...

I assume THIS black bit unscrews from the bottom of the filter 'can' and goes on to the new one?

....And that this IS just a bleed screw/nipple? i.e. once we're all defrosted you just open it, run the pump a few times until fuel flows through and that fill it?

 

[Matt Quinn]

Worth while looking at your diesel filter

IF.. you can dismount it..
Drain it to gauge the state of that Sainsbury fuel,

Then refill with the derv parrafin mix, it should then run acceptably.. Even for a couple of minutes

TBH if I have to take it out at all (doesn't look that hard) I'll just replace it... it's a 'service item' anyway. I'm more concerned about the lift pump. If what's in the filter isn't a candle - and could be drained; well surely there would be some sign of it firing?

- I could be fooling myself but it (the pump) sounds 'less bad' today; I left a thermometer in the car last night (on the floor, near the tank plate) which is now showing a positively balmy 0c.

Top of the pump... inside the car with the floor plate removed... Am I going to ruin anything else I wonder - by pouring a few kettles of boiling water over that area? - It should just run away underneath the car? Likewise; the filter body?

...we're now well above the -4c that even summer Diesel should tolerate; so I'm imagining/hoping this is more a case of breaking up residual wax?

Another question... I assume those tiny studs/nuts holding the retaining ring are metal? I will have sockets that small (assuming I have to replace the pump! - But wonder if they should be pre-treated with WD40 to ensure painless release; given that the replacement won't happen for a few days... From experience, plastic/nylon nuts and bolts don't like WD40; and may be brittle anyway.

 

[Matt Quinn]

OK... so just for the benefit of the tape; as they say in all the best crime dramas... The car is now running; whether the slight rise in temperature (it's now 3c) or the alcohol or some combination of the two I don't know. But...

1) Lift pump still sounds hellish! - Even after 3/4 hour idling to warm things up - it also cuts out from time to time. Replacement about to be ordered!

2) Check engine light is now on... - This requires resetting via OBD? Yes?

I may well go get a couple of gallons of fresh 'winter' diesel in a can; I've no intention of driving the car anywhere like that. Maybe also see if I can find some anti-gel snake-oil additive.

...So, there's a bit of a learning experience! Any tips on the replacement/fault clearing process would be appreciated.

 

[Pugglt Auld Jock]

Hi Matt. If you've seen any of my other posts you'll know I'm an Edinburgh person - North Edinburgh, not far from Leith. I have a licensed version of MES, although it's not been updated for quite some time - works fine with my 2010 Panda and boy's 2012 Punto (both F.I.R.E. petrol engines) and, in happier times, I'd be offering to read your codes and attempt to clear faults for you (thanks for the suggestion PB) however - I'm sorry to have to tell you all that my brother has died and I'm definitely not firing on all four at this time, finding it quite difficult to take it all in actually. I'm hoping that once his funeral has taken place I'll feel a bit more settled and able to calm down a bit.

Think it's going to be a while before I'm feeling like messing about with our cars and my machines though. I'm planning to just lurk around on the forum from time to time just for a bit of "normality" in my life.
Regards to all
Jock

 

[Pugglt Auld Jock]

By the way. I'm not familiar with the Qubo (or any of the diesels for that matter) but I doubt if you need to undo those wee nuts on the tank unit? much more likely that the unit is "twisted" ? Those wee bolts make me feel very nervous, they look almost certain to shear?

 

[Matt Quinn]

Hi Matt. If you've seen any of my other posts you'll know I'm an Edinburgh person - North Edinburgh, not far from Leith. I have a licensed version of MES, although it's not been updated for quite some time - works fine with my 2010 Panda and boy's 2012 Punto (both F.I.R.E. petrol engines) and, in happier times, I'd be offering to read your codes and attempt to clear faults for you (thanks for the suggestion PB) however - I'm sorry to have to tell you all that my brother has died and I'm definitely not firing on all four at this time, finding it quite difficult to take it all in actually. I'm hoping that once his funeral has taken place I'll feel a bit more settled and able to calm down a bit.

Think it's going to be a while before I'm feeling like messing about with our cars and my machines though. I'm planning to just lurk around on the forum from time to time just for a bit of "normality" in my life.
Regards to all
Jock

Hi Jock,

I'm sorry to learn of your loss; it's aye difficult and sobering when any of the family pass on. - Moreso when it's one of your own generation; and that goes for friends too. - Getting past this and getting yourself settled is the important thing. But you do get by it; glib as that sounds.

Fret not about the codes... turns out my wee Vgate (VW) scanner was able to read and reset them. - The errors were all fuel pressure stuff which is unsurprising given the gunk that probably blew through the system. The new pump will likely be here by Thursday, and I'll give the top of the pump area a wee bit of a clean up with IPA (Isopropyl - not Tennents ) tomorrow maybe... spray it with some wd40 and let it 'soften' the those toattie wee nuts that look as if they want to sheer off as soon as you look at them!

We'll see how it goes,
All the best, Matt.

 

[Matt Quinn]

By the way. I'm not familiar with the Qubo (or any of the diesels for that matter) but I doubt if you need to undo those wee nuts on the tank unit? much more likely that the unit is "twisted" ? Those wee bolts make me feel very nervous, they look almost certain to shear?

They do that... don't they. If anyone knows for sure the input would be appreciated. But it does look as though the pump is 'trapped' in place by that ring. I suppose I'll get a better idea once I have the new pump in my hands; is it 'threaded' or some sort of bayonet?

 

[jackwhoo]

Hi,

I have been watching this thread.

Add as much winter diesel as you sensibly can then run the engine to ensure winter diesel get into fuel lines.

Yes replace lift pump, yes oil the nuts prior to undoing though they look ok.
Clean top of tank prior to removing pump.
Mark the plastic pipes which way they attach to pump PLEASE.
find out how to release the plastic pipe fittings to the pump.

Do not change anything else yet , if you do and still have problems you won't know if you have fixed a problem or introduced a problem.

Best wishes
Jack

Ps I wrote this a few hours ago but it didn't send.

 

[Pugglt Auld Jock]

They do that... don't they. If anyone knows for sure the input would be appreciated. But it does look as though the pump is 'trapped' in place by that ring. I suppose I'll get a better idea once I have the new pump in my hands; is it 'threaded' or some sort of bayonet?

Just went back and took a closer look at your illustration. Does look like the ring is holding it down. probably got a rubber seal under the whole lot? good luck with those nuts fella! Most I've seen in recent years are held in with a screw down ring but your's doesn't look like that.

 

[Matt Quinn]

Do not change anything else yet , if you do and still have problems you won't know if you have fixed a problem or introduced a problem.

...Exactly so. I'm of the generation where they first trained you to be a technician before you went off to learn the artsy-fartsy stuff; so fault finding and rectification are second nature. And yes of course you're quite right Jack; I'll deal with the obvious fault(s) before taking anything else apart. - The connectors look as if they disconnect with special pliers; which are on their way.