Water in diesel

[thirdrail]

Looking for help- this is my second season with my 2001 28' TE with a Yanmar and I love her but I have been dealing with one problem. Last year the first few times taking her out the fuel filter collected so much water the alarm went off. Over the next several weeks this occurred several times. After my third tank of fuel it seemed to have stopped. I orginally thought the water was caused by the boat sitting in storage for 2 years with a empty tank. Well I just drained a pint of water out of the racor filter again this past week. Any idea where this water could be coming from as I don't have a clue. My next step is to try and pressureize the system and see if I can find any leaks. Any clues or hints would be appreciated. Thanks Bob

[N4QC]

Water in diesel fuel usually has some of the following suspects:

1. It comes with the territory. Diesel fuel standards allow for a certain amount of water in the fuel. I think that it is .05%;

2. At my fuel source, I try not to be the first one of the day to pump fuel aboard. Have experienced water in the fuel problems within twenty minutes of taking on fuel;

3. Gasket or "O" ring problems with the fill cap;

4. Fuel vent collecting water from rain, spray or wash down;

5. Gasket problems with tank fuel gauge sender;

6. Tank fill hose clamps not tight especially at the deck fill neck;

7. Tank inspection of all fuel and vent line joints;

8. Damaged tank which allows water intrusion;

9. Condensation;

10. Aeration - This occurs when hot fuel is returned to the top of the tank as opposed to the return line being submerged towards the bottom of the tank. The fuel in the fuel tank acts as a heat sink for the heated return fuel. For small capacity tanks and local weather temperatures, over time the fuel supply can heat up approaching 104 degrees F at which time other issues can develop. A drop in rpms, at the same throttle setting, is the most likely while if there are any additives in the fuel such as an enzyme or bio additives, the enzymes can start to become denatured (destroyed). The bio stuff I haven’t figured out yet but the recommended shelf storage temperature that I have seen is 89 degrees F…

Recommend that fuel be purchased from a high volume source as diesel will start to deteriorate after 28 days from the refinery...

Hope this helps,

[RobS]

All great info from Joe. Starting at the source, do you always use the same fuel supplier? Do you know others who use the same supplier and, if so, are they experiencing any water issues?

Are you getting fuel from a marina with inground tanks? Is it possible to get fuel via a delivery truck? Or get a gas caddy and do it yourself and see if the issue goes away.

[thirdrail]

Thanks for the replies, I get my fuel from a truck that delivers right to the marina so I don't think it is bad fuel to begin with. I have checked most of the suggested trouble area's and haven't found anything yet. I guess I will try plugging vents and pressure test, see if can hold a few pounds of pressure. Thanks again