England Ireland Find Havens
England Ireland Find Routes


Avoiding engine problems caused by diesel fuel bacteria

Be the first to comment

What is the issue?
Many varieties of bacteria and fungus feed off diesel fuel in warm conditions. More than two dozen of these will cause engine performance degradation and total breakdown.

Why address this?
Engine failure is far from ideal but many varieties go on to corrode and damage the engine, tank, piping and fuel system.

How to address this?
Use an anti-fungal / bacterial fuel additive when sailing into warmer waters.

Because diesel is an organic substance microscopic fungi such as yeast and bacteria feed upon it in warm conditions. Unlikely though this may seem, diesel contains all the elements these micro organisms require: carbon for food, oxygen for respiration plus dissolved water and other trace substances to sustain their growth and propagation. All that is required is warm conditions and if they get in they can grow to infest the fuel system very quickly.

Contaminated diesel can be picked up from a vendor at any port or simply acquired from the air or moisture that found its way into the fuel via a tank fill. You will typically never know how it came in but, and depending upon the variety you pick up, you will see its effect. In our case the engine simply died one day. I quickly found the fault was fuel starvation as the fuel filters and lift-pump were completely clogged up with a thick black treacly bio-film.

Ease of eradication depends upon the variety of the attacking strain. In our case once we cleared the filters out, discarded the fuel lift-pump that was damaged beyond repair, and filled the fuel with additives. The problem went away. However we did return to cooler latitudes at this point so this was less than a controlled environment, just sailing north could have brought the temperature out of its natural spawning range.

It is generally believed that once the diesel has been contaminated it can be difficult to completely eradicate the contamination. Hence prevention is the preferred route.

With thanks to:
Michael Harpur, Yacht Obsession.

Add your review or comment:

Please log in to leave a review of this tip.

eOceanic makes no guarantee of the validity of this information, you must read our legal page. However, we ask you to help us increase accuracy. If you spot an inaccuracy or an omission on this page please contact us and we will be delighted to rectify it. Don't forget to help us by sharing your own experience.