Q & A — July 2004
By Capt. Ken Kreisler
It’s Good to Vent
2: Fuel filter plugging, and more
is the best way to lay down a bead of caulking? V.S., via e-mail
To avoid a jagged line, squeeze and release the trigger at regular intervals and use a rag to wipe the tip as it accumulates residue.
causes diesel fuel filter plugging? H.S., via e-mail
One of those properties is cloud point, which is simply the temperature at which the paraffin begins to coalesce, turning the fuel cloudy or hazy. Once diesel fuel reaches cloud point, it cannot readily pass through a filter element, and the engine is therefore starved for fuel.
If you operate your engine in cold weather and are experiencing filter clogging, you can avoid this problem by using a fuel heater to maintain the fuel’s temperature above its cloud point. Check with your engine manufacturer if you are considering using one of these products, as some compatibility problems can occur.
A common cause of filter plugging is microbe buildup. Water in your fuel tank is the culprit here. These microorganisms thrive in the boundary between the water and fuel line and multiply quickly enough to overpower any fuel element. Such contamination can usually be seen as a brown, green, or black slimy coating on the filter.
Using a biocide can control the problem, but there is a caveat: With the resultant “dead bodies” piling up, this solid mass, often seen as string masses, can cause additional filter plugging. That’s why repeated changes of both primary and secondary filters is essential. To help prevent the accumulation of water in the first place, use a fuel-water separator and keep your tanks as full as possible. This will reduce the free air space in your tanks that is necessary for condensation to occur.
Need help with a maintenance problem? Write to Maintenance Q & A, Power & Motoryacht, 260 Madison Ave., 8th Fl., New York, NY 10016. Fax: (917) 256-2282. e-mail: firstname.lastname@example.org. No phone calls, please.
This article originally appeared in the June 2004 issue of Power & Motoryacht magazine.