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Diesel waxing  
Diesel waxing - Spospe
Last week I travelled back from southern France to the UK by way of Belgium. When I set off, my vehicle (a 2.5 DI Transit) had a full fuel tank and the weather had been hot and sunny for several weeks, with temperatures in the mid-to-high 20's.

When I got to Belgium, near Bastogne in fact, the air temperature was down to around 5 degrees and in the morning the engine was slightly reluctant to start. After driving for about 10 miles at around 50-55 mph the engine seemed to be misfiring and there was some considerable vibration of a rather 'odd' sort to be felt through the gear lever.

I filled the fuel tank (first fill since leaving the south) and stopped for lunch. When I set off again the engine was a little 'lumpy' for a while and then settled down to run as normal. There has not been any further misbehaviour.

Was I suffering from waxing of the fuel? I have often heard of this term, but never personally experienced it.

Thanks for any help

Tags: technical issues misfuelling fuel economy fuel tanks

Diesel waxing - 659FBE
Your symptoms sound very much like it. In retrospect, it would have been better to refill the tank with the engine running (against nanny regulations but OK with derv) and run it a bit further to circulate the winter fuel before stopping for lunch. Glad you got away with it - a wax ridden fuel filter is not easy to deal with.

Bear in mind that economy will be slightly worse with winter fuel due to its lower calorific value.

659.
Diesel waxing - Hamsafar
Winter diesel (as we are on now) should be free from waxing/gelling down to at least -20?c and -5?c for summer diesel,
Diesel waxing - none
The 2.5 DI engine used to suffer from a build up of air in the injector pipes after a long fast run. This led to misfiring on slowing down or after a fuel stop. The misfire might clear after a while, but sometimes the injectors had to be bled. The Ford mod was re-routing of the leak off pipes.
Diesel waxing - oilrag
There`s a British Standard for Derv in the UK, Its ok to Minus -7c in Summer and -15C in winter
Diesel waxing - Spospe
Thanks for the replies, I had not thought about the fuel filter possibly being clogged with wax, my impression was that it could have been in the injector pump or injector pipes, but thinking about it a partially blocked filter would fit the symptoms.

The fuel that I bought was of course French and I have no idea at all what their summer / winter specifications are in respect of temperature. At the time I bought it the temperature had been in the mid to high 20's for several weeks and I imagine that it would have been 'summer' grade.

Thanks again.
Diesel waxing - Roly93
Was I suffering from waxing of the fuel? I have often
heard of this term, but never personally experienced it.

I very much doubt this indeed. I have 'seen' diesel waxing in the winter of 1980, when I was trying to start an old tractor with the glass bowl above the low pressure fuel pump. The diesel had a milky-like clouding effect as it enterd the pump. But this was probably after a night when it was -10 with wind chill also, and with poor quality agricultural derv.
I think it is highly unlikely that any of us will experience diesel waxing in the UK of Northern France given the generally warmer weather and good quality winter diesels now available.
Diesel waxing - Xileno {P}
Almost without exception it's -15 in central France at some stage over the winter. Never had problems with diesel waxing.
Diesel waxing - gbn
What about just the brand of fuel?

I've driven a fair bit in France and find my fuel economy is rubbish using Agip.
Use any other brand and I'm OK
Diesel waxing - Roly93
What about just the brand of fuel?
I've driven a fair bit in France and find my fuel
economy is rubbish using Agip.
Use any other brand and I'm OK

I've found the same with Carrefor hypermarket fuel, ie loads of smoke and poor fuel cons.
Diesel waxing - bell boy
The diesel had a milky-like clouding effect as it enterd the pump
>>>>>>>>>>>>
>>>>>>>>>>>>i usually find that this is water

Diesel waxing - bell boy
waxing of diesel ive seen and it was a real pain 20 odd years ago was like a crystalisation in the diesel and the only solution was a heating of the tank and trying to get it through the pipes,interesting about the filter never thought of that
if you imagine the fuel lines are under the car its still quite possible that it was waxing if you consider the wind chill factor in to the equation
Diesel waxing - quizman
There is no chance that diesel will freeze at +5C, at -5C with wind chill and summer diesel it might.
If it gets very cold this winter it is best to buy some additive to put in the tank to stop the diesel freezing, I used to put paraffin in the tractor to thin the diesel down a bit, but it would probably ruin the fuel pump in a modern diesel car (esp a Mondeo TDCI)
One cold winter many years ago I stored several cans of diesel in the kitchen to keep it warm. My wife was not very pleased at all!.
Diesel waxing - oilrag
Re reading the OP`s post, the temperature mentioned is 5c, *windchill* can`t reduce the fuel temperature below this point.
I don`t think (IMHO) it was waxing because ( unlike the old carburetor iceing) once filter plugging occures the wax in the filter remains even if the temperature then rises above the fuels cloud point. The only way out is to fit a new filter.
I think more filters are plugged by ice formation than by fuel waxing these days. When filters have enough water in the base to have contact with the filter element itself. But then, this is an above freezing temperature... And is highly unlikely unless fuel is sourced from poorly maintained company tanks as opposed to from normal filling stations.
It *sounds* fuel related, but its hard to see France having wildly different fuel specs to ours given the EU and all that.


Diesel waxing - Hamsafar
Windchill only affects animals, it makes it feel chillier than it is (hence the name), it doesn't reduce the actual temperature, only the perceived temperature.
Diesel waxing - oilrag
Quote (Wikipedia)
"The concept of wind chill is of particular significance in very cold climates such as the Arctic and Antarctic, at high altitude, at high speeds, or in very high winds. It is of great importance to the survival of humans and animals, and can even affect machinery and heating systems."

Diesel waxing - local yokel
You'd need air much colder than +5 and a strong wind blowing over a cold vehicle to achieve significant windchill. We used to get that kind of weather in N Norway from time to time. So cold that the lube oil in the Wessex Vs was drained and kept in heated tanks, as was the fuel. We had only a few minutes to get them started before it cooled.

I don't know what the OP was suffering from, but I doubt it was diesel waxing.
Diesel waxing - jc2
There is certainly some odd derv in France-I filled my car at a small Elf garage and noticed that I could fill it straight to the top-no foaming or bubbling whatsoever.Querying it later was told that Elf must have put too much anti-foam agent in that consignment.
Diesel waxing - Statistical outlier
Some woolly thinking here.

Wind chill is a process where heat is removed from an object by conduction of heat from the warmer body to the cooler air passing over it.

It will affect anything that is warmer than the ambient air temperature. Its effects grow with increase in temperature differential and with increasing wind speed. It cannot bring the temperature of the warmer body below ambient temperature. It also doesn't affect anything that does not have a temperature differential to start with - a car parked for longer than two or three hours for example.
Diesel waxing - bell boy
let me get all this right then..........
spose is driving his transit which is a commercial vehicle where the tank is large and plastic and low and also possibly open to the elements if its pickup style body,the pipes are not protected by anything the filter is well down on older transits and the man drove 10 miles before he had a problem?
how can anyone say after all that that windchill on the system can not have an effect?
maybe a walk in a wind at 50mph may change some people minds, as that is what spose was doing in reverse :-o
Diesel waxing - Statistical outlier
It could and would have had an effect. It would have been dragging the fuel pipes and their contents down to the ambient temperature (5 degrees according to the OP).

For you and I, operating at 37 degrees, 5 degrees would be a significant problem. Diesel wouldn't be affected.
Diesel waxing - cheddar
As with fast flowing highland streams resisting freezing due to flow, fuel flow should reduce waxing when on the move, if the Transit was doing 25mpg at 50mph then it would use two gals, say 10ltrs an hour so 166ml or so per min would flow through the system, not an insignificant amount.
Diesel waxing - cheddar
>>Some woolly thinking here.

Wind chill is a process where heat is removed from an object by conduction of heat from the warmer body to the cooler air passing over it.

It will affect anything that is warmer than the ambient air temperature. Its effects grow with increase in temperature differential and with increasing wind speed. It cannot bring the temperature of the warmer body below ambient temperature. It also doesn't affect anything that does not have a temperature differential to start with - a car parked for longer than two or three hours for example.
>>

Windchill can reduce a temp lower than ambient when moisture is involved hence (moist) skin is very prone to the effect, with regard to fuel lines if moisture is in contact with them from spray or condensation, i.e moisture coming out of the air as temp drops. I have cribbed this from Wilkepedia by way of an explantion and modified it to make it relevant to the subject:

The wind chill temperature is lower than the air temperature because any windchill increases the rate at which moisture evaporates from a wet object, the phase change of water from liquid to vapor requires the molecules to reach a higher energy state, the energy is acquired by absorbing heat from the surface of the body upon which the moisture is sitting by conduction.
Diesel waxing - Statistical outlier
A valid point, and one that I'd neglected. Evaporation will indeed make a difference, and could be relevant. I'd be surprised if it was much of an issue in this case though, certainly not to take the system down below zero.
Diesel waxing - none
I really can't understand why everone is arguing the toss about fuel waxing. I'll bet my life that of 100 different reasons for the misfire problem, waxing stands at 101.
I've only ever seen it occur overnight a couple of times (UK) and that was back in the 60's. And that was when cheap die cast truck door handles used to snap because they were so brittle with the cold. More recently, for the last ten years I've worked on a mixed size diesel engine fleet and never come across a waxing problem.
Has any backroomer recently experienced (10yrs) an absolutely indisputable fuel waxing problem ?
Diesel waxing - wemyss
I agree None...The only time I have seen it was it happen was in the winter of 1962. I was on my way to London early morning in a HIV. Set off from Belper in Derbyshire and the sides of the road were littered with other HGVs. I got as far as Melbourne Derby and I too came to a halt at the side of the road.
Had too wait a hour or two whilst things came to life back at the ranch. Up till then I had never heard of diesel waxing.
The mechanic turned up later and explained what it was and he himself had only just heard of it.
He bought 4 gallons of paraffin with him which he put in the tank. With some kind of heater he got fuel flowing through the filter which was exposed on the side of the engine.
He managed to get the engine started and followed me as far as Hinckley heading for Crick where the M1 then began.
All along the side of the road were HGVs broken down and by now word must have got out as to what the problem was. They had fires lit underneath fuel tanks and it was like a re-enactment of the retreat from Stalingrad.
By the time I got home in a couple of days the papers were full of this happening and I remember the fuel companies saying it wouldnt happen again in future years as they would introduce winter diesel.
To this day I have never personally known of it happening again although I have read discussion on this site as if it were still a regular occurrence.
The only winter to even compare with this one was 1947 which I remember vividly. But being only a boy at this time I would have known nothing about diesel waxing so I wouldnt know if there had been a problem then. Apart from the fact my best mate whose father and elder brothers ran a haulage company and he used to talk of nothing but lorries so feel sure it would have been his main topic for the next month.
Perhaps with red diesel they don't use an additive in winter and it could occur on farms but even that seems a long shot.
So perhaps someone who has experienced this in modern times would explain where and when this occurred.

Diesel waxing - NVH
Just a couple of points:
1. Continental winters can and do drop to below -20C from late November, so diesel additives take account of this. I started my Xantia at -15-20 in the mornings without a problem.

2. French diesel includes biodiesel, which RAISES the freezing point compared to staright disel.

Farmers' Weekly has just published some info on tractors, biodiesel etc which I'm sure the BR will find interesting:
tinyurl.com/y68qzl
URL=www.fwi.co.uk/Articles/2006/11/01/99067/
Biodiesel+as+a+tractor+fuel.html

Did you know Herr Diesel ran his first motors on groundnut oil ??

Diesel waxing - nortones2
Actually they were able to run on a variety of fuels including coal dust, but then Ackroyd-Stuart had already proven the concept, and with Hornsby, had produced many commercial engines based on the hot-bulb CI priciple, with the first fuel injection system. A little reference:en.wikipedia.org/wiki/Herbert_Akroyd_Stuart
Diesel waxing - bell boy
1980 in the commercial vehicle park durham city it was getting to the state of boredom calling out recovery companies to light a rag under the tanks
Diesel waxing - Spospe
Thanks to everyone for your contributions, but my follow-up question must be, if I was not suffering from the onset of waxing, what was the problem?

I have had the vehicle (2.5DI Transit) for 6 years and done 70,500 miles, it has never behaved in this way before. To reiterate, the symptoms were, lumpy runing, loss of power and heavy low frquency vibration (felt mostly through the gear lever). After a stop for lunch of about an hour and a top-up with local fuel it ran OK. It continues to run OK up to today and has covered another 1000 miles.

Remember the original fuel was purchesed in the south of France (from an Intermarche) where it had been 25+ for weeks and the probem occured in Belgium after overnight frost.

Any ideas?
Diesel waxing - oilrag
Spospe, You moved the goalposts :) now you`re mentioning *frost* rather than 5C...
I still cant see it waxing as the much colder high French alps would also be within reach of your full tank of fuel
and difficult to see how the French would not legislate for this in their fuel specs.
Also a waxed filter *stays* waxed even if the temperature then rises.
Have you water in the filter, to the level that it can *wick* into the element?
An iced, fuel restricted filter IMHO, may just give the symptoms you describe, if its been frozen overnight.
Diesel waxing - quizman
>>>Has any backroomer recently experienced (10yrs) an absolutely indisputable fuel waxing problem ?




They put additive in red diesel from october 1st. The trouble is that sometimes we have some summer diesel left. I have not had any diesel waxing recently because the weather has been warmer and I put an additive in if the weather gets cold. My mechanic stocks up with fuel filters in the winter for his customers.

I have seen diesel waxing many times years ago, the filters get full of red wax and have to be changed. We usually use a space heater to warm the tractor up.

I remember Anika Rice advertising Esso diesel which was supposed to be OK to -20C. I had trouble with Esso freezing up and comlained, they told me it was the wind chill, I said that Anika said nothing about that!

Cars now have plastic tanks and the engine is enclosed so there is not much waxing, but if it got very cold I think that quite a few diesel cars would be in trouble. Then all the anti diesel people on this forum would have a field day.
Diesel waxing - David Horn
Wind chill has no effect in laminar air flows (ie, smooth air around or under a car).

What about lighting a small fire under the fuel tank?
Diesel waxing - quizman
>>>What about lighting a small fire under the fuel tank?



I wonder what the insurance company would say when the car is a charred wreck?
Diesel waxing - Spospe
Oilrag, I did not intentionally 'move the goalposts', so sorry if that seemed to be the case. On the day in question, the air temperature was about 5 degrees when I set off, but that does not exclude a ground frost, with white, ice covered grass.

If the symptoms that I experienced were not due to waxing, then what did cause the problem? I have never had this kind of problem before, and as I have said before, after an hour's stop and a top-up (about 75% more fuel), the engine ran normally.
Diesel waxing - jag
does the transit have apencil filter on the end of the fuel pipe in the tank?
if so then quite likley that it was getting blocked and adding fresh fuel shifted the dirt off it.
had this happen to a leyland tractor in years gone by. jag.
Diesel waxing - oilrag
Spospe, Sorry, I did not intent to imply that you "moved the goalposts" on purpose, just that more detail ( *Frost* added to your earlier 5C) potentially expanded the range of possibilities :)
Any water in your fuel filter?
To be honest though, I think it would need a penetrating frost to freeze water in the fuel filter and maintain it for a while with a running engine.
Maybe it was not fuel related and the the hours stop itself allowed heating of another engine related component?
Good luck anyway :)
Diesel waxing - oilrag
Just a further thought.. I wonder if ( through no fault of your own) that you got a bad tank of fuel, such as a messed up
mix of biodiesel from the garage concerned.
Out of technical interest, if it were my vehicle I think I would take off the fuel filter, check for water, then cut it open with a hacksaw and examine it for wax/dirt on the element.
Then you would have the definative answer as to whether you had fuel waxing, as if so, it will still be in the filter.
Time (IMHO) for a new fuel filter anyway given the fuel concerns.
Diesel waxing - Spospe
The Transit does have a water-in-fuel indicator, which in my case at least is know to work correctly and on this occasion it did not show any water being present.

I do not know if there is an additional filter in the fuel tank, but the main filter (mounted on the engine block) was changed (by me) about 12-13 thousand miles ago.

It is possible that I could have got a 'dodgy' batch of fuel, but it is strange that the problem only showed up after an overnight stop with its low temperatures.

I fear that we will never get a definitive answer now: thanks to all of you for your suggestions and help.
Diesel waxing - bell boy
can you not go back and do the whole thing again ;-)
spose not ;-(
Diesel waxing - cheddar
Wind chill has no effect in laminar air flows (ie, smooth
air around or under a car).


Laminar air flows in this context mean that the air flowing close to the surface is moving more slowly than the air further away, i.e. more slowly than the vehicle speed through the air however if moisture is present then windchill is still a factor albeit probably an insignificant one.

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