IAM on Diesel Waxing

[grober]

With -20°C forecast in some parts of the UK, the IAM (Institute of Advanced Motorists) is warning drivers of diesel cars to remember that their fuel can waxover in extremely low temperatures, which could damage the fuel filter and cause a breakdown.
Neil Greig, IAM Head of Policy and Research, said: "Waxing is the formation of crystals in the diesel which block the filter. If you drive a diesel vehicle, it pays to try and park in a garage or sheltered area, and try to not to leave your vehicle standing unused for too long,"
"If you can’t park in a garage, do ensure that the engine bay of the car is parked downwind, so that the wind hits the back of the vehicle first. After starting the engine, let it idle for 10 minutes before driving off, as this will let the heat from the engine warm the filter and pipes."
Lorries with exposed fuel tanks and fuel pipes are most at risk but cars and vans can also be affected if it’s cold enough.
Water in diesel fuel tanks and filters can also freeze. Mr Greig advised: "Keep the fuel tank full and, if possible, fill it before arriving at home as this will prevent the build up of condensation on the inside walls of the tank, helping prevent water building up in the bottom of the tank."

I have a feeling some diesel Mercs have heated fuel lines but not sure?

 

[wemorgan]

With most cars having the fuel tank under the rear seats is it really going to matter what direction the car is pointing?

Or is it the fuel within the engine bay fuel lines that are most at risk of freezing?

edit: I also thought that diesel sold in the pumps during the winter months had an 'anti-waxing' agent.

 

[BenzedUP]

Thanks for that useful info, I havnt used my car for about 4 days now but it's been in the garage - guess it's better to be safe than sorry.. i'll take it for a spin tomorrow before sunday the heavy snow returns!

 

[mbenz76]

I don't have my E350 yet, but it will be my first diesel.

I was aware that it suffered problems in extreme cold but don't know much about it.

So if you park up and leave the car in freezing conditions, but don't move it until it had warmed back up, would the crystals melt and all would be well, or once they have formed do they stay?

 

[grober]

Sorry guys can't answer your questions definitively just quoting the IAM guy.
This gives some useful info. http://www.bp.com/liveassets/bp_int...ownloads_pdfs/f/FN_winter_diesel_problems.pdf

 

[Satch]

Winter diesel sold in the UK from October onwards has to conform to British Standard BS EN14214 which requires a cold filter plug point of no higher than -15C but you get clouding (just like olive oil when it gets cool) before that. Old, cruddy fuel filters may start to get in trouble before then because the very small wax crystals that would otherwise pass through start to get stuck onto existing ashpaltine and wax deposits.

The Northern European Winter diesel mix is good to about -24C as sold. Below that it has to be mixed with paraffins (i.e kerosene, maybe something like AvTur because there is lots around) and in really cold climes can find diesels running on mixes like this:


Table 1: Diesel fuel operating temperatures (NB: Northern European, Not UK spec: our summer diesel is only good down to -5C)

Diesel fuel
summer grade
winter grade
% of two stroke oil

opr.temp as sold
-11 C
-24 C
0 %

with 10 % paraffin
-13 C
-27 C
0 %

with 20 % paraffin
-15C
-30C
0 %

with 30 % paraffin
-17C
-32C
0 %

with 40 % paraffin
-19C
-35C
0 %

The following must not be used without added (ash-free) two-stroke engine oil:

with 50 % paraffin
-21C
-38C
0,50 % 2-S oil

with 60 % paraffin
-23C
-40C
0,75 % 2-S oil

with 70 % paraffin
-25C
-42C
1,00 % 2-S oil

Feel brave enough and you could run on 100% AvTur down to -47C. (Since at 35,000 feet the air temperature is about -55C, you now know why aircraft have fuel heaters!)

There is a product called Wax Breaker that improves cold performance by changing the wax crystals form but useless when wax has already formed: has to be premixed.

 

[mbenz76]

Winter diesel sold in the UK from October onwards

Sorry if I am being dim but my E350 will be my first diesel.

So is all diesel sold in the UK from October (to when?) "winter diesel" and therefore good to -15C? Or do you have to find somewhere that specifically sells it?

 

[Merc Owner 2B]

Sorry if I am being dim but my E350 will be my first diesel.

So is all diesel sold in the UK from October (to when?) "winter diesel" and therefore good to -15C? Or do you have to find somewhere that specifically sells it?

Don't worry about it. I've driven them for years without issue. Diesel stocks are adjusted as required so just buy from wherever you like. Supermarkets tend to be best as they have a faster turn-around. I guess melting snow finding it's way into underground storage tanks is an issue but that can happen with petrol!

Enjoy your 350!

 

[James Rothwell]

I have never known diesel to wax in this country, even in Norway when it was very, very cold people where still using diesels some I admit had aux heaters to keep the block and fuel lines warm.

 

[219]

When we ran diesel vehicles many years ago ( trucks , plant , vans & Land Rovers ) we just used to add some petrol to prevent waxing - my dad reckoned you could go as high as 50:50 without doing any harm . I did it inadvertently a couple of years back when I started to mis-fuel a diesel van , realised after only about £10 worth of petrol and just filled the rest of the tank with diesel - no harm done .

 

[raymont]

When we ran diesel vehicles many years ago ( trucks , plant , vans & Land Rovers ) we just used to add some petrol to prevent waxing - my dad reckoned you could go as high as 50:50 without doing any harm . I did it inadvertently a couple of years back when I started to mis-fuel a diesel van , realised after only about £10 worth of petrol and just filled the rest of the tank with diesel - no harm done .

With modern diesels and their high pressure pumps, fine tolerances etc. I don't think it would be a good idea to add petrol, or probabaly anything else, to the diesel.

Plenty of reports of mis-fuelling around which have resulted in very large ( 4 figue) bills even when the amount of petrol hasn't been that great.

 

[219]

That incident was with a Fiat Scudo van . I'd imagine most 'normal' Diesels that run happily on veg oil etc will be fine with a little Petrol .

Incidentally , we have been seeing temperatures of -20 around here overnight , with it not rising above -5 during the day . Yesterday , I went outside to start a diesel Ford Focus I had been given by the Fire Brigade while my van was being serviced : turned on , waited for the glow plug light to go out , cranked for about 5 seconds - nothing . Repeated the process about 20 times , allowing time in between attempts for the battery to recover , before the battery gave up - then had a problem finding out how to open the bonnet as no handbook in the vehicle , some Fords now have a keyhole behind the Grille badge ! Started my 500 to give it a jump ( my car started on the first compression , OTG showing an ambient temperature of -8.5 at 3 in the afternoon ) . The Diesel car had been almost starting towards the end but with the battery running down was just not turning over fast enough - with a jump from my battery it eventually caught after a further three attempts .

Returning home later at 6 pm with the Corsa Van it was indicating outside temp of -12.5 !

Hot tap in kitchen has been frozen for three days now .

 

[mbenz76]

Hot tap in kitchen has been frozen for three days now .

Blimey! How cold is the inside of your house!

We have had the central heating running almost all night and all the time we are in the house set at about 22C. It's toasty warm in our house

I do wonder how the sewers underground cope in extended periods of freezing temperatures. Last thing we want is sewers freezing and toilets backing up

 

[219]

We have had the heating on constantly too , not to mention the coal fire in the living room ; the kitchen is an extension outwith the gable end of the 150 year old cottage and probably about 100 years old in itself . I suspect the pipe is freezing under the kitchen floor as it runs alongside the heating pipes within the house , and once it comes up from the floor behind the sink , I have wafted a hot air gun along its length without any joy .

At least the shower and the hot tap in the bathroom works .

 

[mbenz76]

We are in a new build which is very well insulated (as I guess they all are these days) so warm as anything here.

Went to work the other day (heating went off about 7am) and got home early just before the heating came on at 5pm and the temperature in the house was 17C. So a 4-5C loss during 10 hours of sub-zero outdoor temperatures. I thought that was quite good personally.

I do feel sorry for the people who have no electricity and can't heat their houses - they must be freezing, and the condensation that will be building up on everything in their houses is just an insurance claim waiting to happen.

 

[Satch]

I have never known diesel to wax in this country, even in Norway when it was very, very cold people where still using diesels some I admit had aux heaters to keep the block and fuel lines warm.

Norway uses the North European Winter mix rated to -24C. Diesel waxing can and does happen but you are right: not very often in England.

Hundreds of diesel cars break down as mercury dips below minus fifteen

"SCOTLAND is so cold that even the diesel in car engines has started to freeze.

Breakdown firms have dealt with hundreds of calls in the last few days from drivers stranded by frozen fuel.

And with the great freeze grinding on and on, they expect hundreds more.

Dan Robinson, of Green Flag, said last night: "We've seen at least 300 cases of frozen diesel in Scotland this week.

"The fuel becomes waxy, blocks lines and the filter and the car won't start. The only real solution is to get the vehicle to somewhere warmer."

Gavin Hill-Smith, of the AA, added: "Most diesel in the UK is good down to about -15. After that, it gets affected."

Hundreds of diesel cars break down as mercury dips below minus fifteen - The Daily Record

Thousands of people in the Highlands suffered temperatures far lower than -15 on Thursday night."