Are your Diesel fuel filters clogging up?

[Bob F]

Article from Truck & Driver magazine...

 

Apparently, lorry drivers have been expressing concern at the quality and effect of the fuel they have been running their vehicles on, now that up to 5% of all diesel contains biofuel.

 

Despite the insistance of the fuel companies that all fuel sold in the Uk meets quality standards, there is growing unrest among vehicle manufacturers and trade associations that diesel fuel could have an adverse effect on truck engines and fuel systems.

 

To meet the government's renewable transport fuel obligation, refineries are currently adding upto 5% biodiesel to diesel fuel and they are not obligated to advertise this.

 

However, even at this level drivers have reported problems with filters becoming clogged. There is evidense of algae growth in the fuel and the finger of blame is being pointed at its biodiesel content.

 

One driver says their fuel filters and pumps began clogging up after they filled up at a service station. The driver was unaware that biodiesel had been added and said,"If a lorry runs on biofuel it normally needs more frequent oil changes and more frequent filter changes. How can this happen if you do not know that you are using dodgy fuel? Biofuel also increses running costs, something none of us need at the moment."

 

Diesel fuel sold in the UK must reach European benchmarks adopted by BSI British Standard - BS EN590 - which allows it to contain anything between 0% and 5% biodiesel. Fuel leaving refineries is meeting this standard, but manufacturers think problems are arising in the storage and distribution process.

 

Biodiesel is Hydroscopic, meaning it attracts water from the atmosphere. Water in diesel fuel can lead to growth of algae, which impairs the fuel quality.

 

Not only that but biodiesel also acts as a solvent, cleaning sludge from the fuel system's pipes and eventually blocking the filters. Although fuel companies argue that 5% is too low for this to be a major problem, truck manufacturer MAN are recommending customers halve the period between filter changes if they are unsure of the quality of the fuel.

 

But it is Biodiesels' capacity to degrade over time that is causing the most alarm. As the fuel leaves the refinery people are reasonable confident that the fuel meets the BS EN590 spec. The problem is in the storage and distribution process where it's not handled properly. It sits in bulk too long and degrades fairly quickly.

 

Daf Trucks says it also has concerns about biodiesel, but thinks the adverse effects are more likely to become apparent at 10% rather than 5%. However, a spokesman from the BSI confirmed that the spec for EN590 will change in a few months and the biodiesel limit will rise to 7% volume.

 

Bunkering network Keyfuels says it buys its fuel from a supplier and adds the biodiesel itself. A spokesman adds,'We can't dictate the fuel mix the way it's supplied. What we can guarentee is the fuel in our network is within the British quality standard dictated by the BSI.'

 

The UK's fuel companies' trade association, the Petrol Industry Association (PIA), says it is not any great secret that biodiesel has been used in diesel for more than a year. A spokesman says there were some housekeeping issues at some service stations during the early days of biodiesels introduction. But, he adds, 'We are not aware of any specific problems relating to biodiesel introduction so far as users are concerned, other than some reports last winter with vehicle filter clogging problems among a few fleets experimenting with blends higher than B5 (5% biodiesel). Filter blocking and biofuel falling out of solution are potential issues but should be addressed by adherence to the applicable fuel specification standards.'

 

End of report.

[Coddy]

Hi Bob

 

Interesting article, I am not sure if those who have diesel engines know but most common rail engines, those with High Pressure systems, are not all compatable with bio-fuel and may cause major problems with seals and injectors!

 

It seems that it is not uncommon to have fuel filters block up within weeks or months depending on use.

If however thay are suggesting that an algae growth is happening in trucks which get through loads more fuel than our craft, what is happening in boat tanks?

Do we need to add some of the wonderful additives that are available to reduce this happening to our fuel?

 

Coddy

[duncan]

Hi Bob

 

Interesting article, I am not sure if those who have diesel engines know but most common rail engines, those with High Pressure systems, are not all compatable with bio-fuel and may cause major problems with seals and injectors!

 

 

Coddy

I think it's important to keep any discussion alligned -

 

Pretty much all diesel can have 5% bio fuel mixed in - the resulting fuel is not considered bio diesel. It complies to EN590:2004 and may or may not be designated B5 depending on where you purchase it.

 

Red diesel has had seperate regulations (BS rather than EN) with BS2869:2006 but this also permits 5% biofuel by volume. As the sulpher content of this coverges with that of EN590 it's likely that we will end up getting diesel to the (more) common EN590 standard in time.

 

All the above is history - the concern seems to be the impact of the proposals to increase the permitted proportion of bio fuel in 'standard diesel' to 7, 10 or even 20 (if you listen to some of the arguments being put forward to the ESO).

 

Many would say we need a lot more facts from the sustained use of B5 in a range of engines and conditions before 'moving on' - others claim the environmental benefits of such an increase more than make up for any minor risks to mechanical parts...(lets not get into the wider macro economic arguments the other way!!!)

 

Given that we boat owners probably check our fuel filters 100 times more often than car ones, and carry spares etc, it's the wider issues like seals and other potential corrosion issues (associated with bio fuels) that worry me as they will be expensive, potentially dangerous and difficult to monitor.