Bad Diesel Fuel?

[javenius]

While having the fuel filters changed this fall, some dark substance was noticed in the bottom of the three Racor bowls. These filters were changed last fall and only had about 60 hours of use. The dark material was slimy but we were able to remove it. The Racor filters themselves were not bad or blocked with slim. Additionally, the engine spin-on filter was replaced but did not appear to have any of the dark material trapped inside. There was no water in the bowl.

Each tank of fuel purchased this summer was from a high volume marina and all fuel was Valvetech.

A good dose of biocide and stabilizer has been added to both tanks.

I found it odd that this stuff was in the bottom of the Racor units and not in the filters. Is this bacterial growth? Since the filters were relatively clean can I assume this stuff did not get into the engines?

Once it goes back in the water next spring, I plan to add more biocide and top off with fresh fuel frequently (now about 80% full for the winter) then watch for any more accumulation in the bowls. Anything else?

 

[fwebster]

Rather than post the entire procedure, may I suggest that you go to opening page of this site.......click on "home" at the top of this page then go about 1/2 down. There are a series of articles there.........go to the 3rd one down. That is an article about diesel fuel system management and will describe the best way to avoid what you are dealing with.

A couple of things you mention lead me to believe you have a microbial build up in your tanks. First, you can't look at the Racor element and tell much of anything. The black crud/slime in the bowl comes when the sludge hits the Racor and breaks up. Some sticks in the element, the remainder falls into the bowl.

Next, when you described your plans for spring, it indicates you leave your tanks less than full. That is the most likely cause of your problem. The air above the fuel in your tanks is moisture laden so any temperature change causes moisture to condense on tank walls in the area above the fuel. Water droplets fall into the fuel and accumulates at the bottom of the tank. Diesel fuel will form microbial growth in the presence of moisture, so you have a sludge farm at the bottom of the tanks. Keep your tanks full to avoid the sludge.

Finally, Valvetech fuel doesn't guarantee anything except that you are paying 3-4 cents a gallon more for the fuel. This is because Valvetech doesn't control the addition of the additive nor do they monitor the fuel quality. The amount of additive is totally controlled by the vendor or marina you bought it from. At our marina, the dockmaster started out addiing the Valvetech additive......I've watched the process over the last 6 months and now the guy who cleans up the bathrooms and empties the trash cans treats the fuel. He's good as gold but is mentally challenged and cannot read and comprehend well enough to get a drivers license. I am sure your situation is more positively controlled, but my problem is the process is uncontrolled and we just don't know.

Read the article on diesel management and let us know if you have any questions.............

 

[WarrenG]

Frank,

What do think of this product?

BioGuard Plus 6™ by Vavtect. They say it takes care of it all?

WarrenG