Are blocked filters affecting your production? Fuel filter issues are, as ever, on the increase. We can explain why your agricultural vehicle’s filters are becoming blocked with sludge and the steps you can take to stop it.


Why do fuel filters get blocked?

Fuel filters are becoming blocked due to a range of issues, this includes fatty biodiesel precipitates, hydrocarbon wax build-up from storage at cold temperatures, and sediment in the tank. ‘Diesel bug’ can also be an issue from incorrect storage. 

It was previously known that red diesel predominantly had these issues, but more recently, we are seeing that white diesel is encountering the same thing too. We look at the issues in more detail:


fuel filter

Taken from Exocet’s Spring 2021 Newsletter


Diesel Bug

Diesel bug is microbiological growth in the fuel. This may be the case if you’re seeing black, grey or brown slime blocking your filter, rapid proliferation, a sulphurous smell, water in the fuel, and fuel starvation.

To treat this, we can supply Exocet Anti Bug Kill, and a review of your fuel storage tank. If water is getting in, it can cause this issue, so this needs to be fixed. 


Biodiesel Precipitates

As biodiesel is made from used fats, this can clog fuel filters. This may be the issue if you notice white deposits floating on the fuel, fuel starvation, and greasy brown residues stuck to the fuel filter. 

For high turnover vehicles, we can offer Exocet Gas Oil Supreme or Diesel Supreme to be used with every fill. For tanks, we recommend adding Exocet Gas Oil Conditioner. Any immediate block issues can be treated using Exocet Sludgebuster. 


Hydrocarbon Wax

Hydrocarbon wax build-up is associated with keeping fuel in low temperatures. This is more often seen in the transition period between summer and winter grade fuel and vice versa.  Larger hydrocarbons form in the fuel and solidify. You will see this on the filter as either white, yellow, or in red diesel pink wax.

To combat this, ensure you are using the correct grade fuel, or use winter-grade year-round. Exocet Anti – Wax can be used to lower the CFPP (Cold filter plugging point) temperature, but this is only a prevention method. 



Sediment issues happen after the accumulation of solid material within the fuel tank over a period of time. This can be due to contamination of the tank from the environment around it, or poor oil tank maintenance. 

To resolve this, we recommended a professional tank clean. Exocet Sludgebuster can disperse small amounts of sediment, and Exocet Gas Oil Supreme/Diesel Supreme or Exocet Gas Oil Conditioner can help to prevent build up on your clean tank. 


If you would like more information on which fuel additives can help, please feel free to contact us and our knowledgeable team will do their best to assist you. 

Signs, Causes & Remedies of Fuel Filter Blocking Issues
Article Name
Signs, Causes & Remedies of Fuel Filter Blocking Issues
We can explain why your agricultural vehicle’s filters are becoming blocked with sludge and the steps you can take to stop it.
Publisher Name
Quad Fuels