Water in fuel filter warning

[Boatagain]

After about five hours of running at about 2100rpm yesterday, and 15 minutes from the dock, the warning popped up. Since I was so close I powered down to idle and made it home with nary a hiccup from the engine.

I'm guessing that the water formed in the tank during winter storage. The tank was about 85% full.

The Volvo D3-150 manual has a very clear diagram showing how to drain the water from both the pre and main fuel filter. It doesn't look too tough,but since I'm new to this, I thought I'd post and see what more I can learn. I'm assuming there's more water in the tank. Is there something I can do to get that out as well? Any and all input would be appreciated. Thanks.

 

[Kenny Marrs]

The good news is the water will sink to the bottom of the tank. So you should be able to get the majority of the water out before emptying the entire tank.

I would drain the filters first, run the engine, and drain again. Depending on how much water is in the tank this process may have to be repeated a few times. You can also add some fuel additive to the tank to help out.

The best thing to do when storing the boat is to leave the fuel tank 100% full. This way there isn't any room for condensation to build up.

Thanks,
-Kenny

 

[Boatagain]

Thanks Kenny, I actually was aware that winter storage with a full tank was advisable, I just forgot that lil' detail last fall. Doh! I will follow your suggestion to get the rest of the water out. I appreciate your response.

 

[Sweet_Pea]

We had the same thing happen on the way home from Roche Harbor last year. We bled some fuel, but saw only fuel, no water. Had the boat serviced and filters replaced a few weeks later.

This weekend, we got the warning again. Bled about 6 oz of fuel, again, didn't find any water.

Sounds like the additive might help, but what type? Searching the forum, we found reference to FPPF http://www.fppf.com/products-by-name?task=catalog.product&id=4. Would this help with the water issue?

 

[Brian B]

This is the FPPF product you would want to use. http://www.fppf.com/products-by-name?ta ... duct&id=16
You will find in older posts that this is the only product Mack Boring recommends to be used in the Yanmar engine.
I treat every gallon of fuel I add to the boat and have not found one drop of water in the filters when I change them.
Besides condensation in the fuel tank you could also get water in the fuel from the source you purchase from.

 

[NorthernFocus]

The water sensor measures conductivity/resistivity of the fluid between two points. It doesn't necessarily take pure water to become conductive enought to trigger the alarm. So not seeing water when you drain the bowl isn't indicative of none being there. Water may be suspended in an emulsion that isn't readily apparent on casual visual inspection. Particularly after "squeezing" through the bowl drain which would tend to mix it up. Unless you're using a fuel additive(or the vendor who provides the fuel is doing so) it should separate if allowed to sit quietly in a glass container. Might take a few hours depending on temperature, purity of the fuel, etc.

Personally I'd treat it as if it is real in the short term and get to the bottom of it in the long term. Water doesn't go out of the tank on it's own. It only gets worse. And in my experience with diesel powered boats, fuel problems are second only to electrical power management as the most likely problem that will leave you stranded(assuming you're capable of replacing the impeller in the water pump).

 

[Sweet_Pea]

Thanks for the link, Brian.

Dan: makes sense that the water may have been stirred up and emulsified while cruising. We'll start using additive.

 

[R Baker]

In 7 years of ownership of a small trawler with a Yanmar 2JH series engine I never experienced water in the fuel, or at the water separator. Perhaps a bit of dumb luck; but the precautions I have taken were: 1. Add a diesel additive that disperses any water at fill ups, and 2. Apply a bit of grease around the O ring of the filler fitting to prevent any water ingress. I should add, contrary to popular advice, never worried if the tanks were full over the winter - but probably about 1/2 to 2/3 full.
RB

 

[NorthernFocus]

In 7 years of ownership of a small trawler with a Yanmar 2JH series engine I never experienced water in the fuel...contrary to popular advice, never worried if the tanks were full over the winter - but probably about 1/2 to 2/3 full.

Noting the location in your profile, it's worth mentioning that for those of us living in higher latitudes or areas of lower humidity, condensation due to the tank level is less of an issue.

 

[Lenny and Louise]

We solved the water in fuel problem by replacing the defective sensor.

 

[Sweet_Pea]

We drained 8 oz of fuel again yesterday on the blocks in dry stack. The boat had sat for nearly a week...plenty of time for any water to settle. All we saw is fuel. Ordered additive any way, but just wondering about the fuel sensor now. Where is it located? Is it an easy job to swap out?

 

[Lenny and Louise]

Amy and Paul,

The water in fuel sensor is located at the bottom of the secondary fuel filter. On the Volvo D-3, this is mounted on the forward port (relative to the boat) corner of the engine, under the shroud. The wires are clipped onto the sensor and can be removed by feel – in fact it is virtually impossible to see. After the filter is spun off the engine, it is easy to remove the sensor.

We had drained the primary filter a couple times with no sign of water. The alarm was intermittent – the worst of all possible conditions to trouble shoot. We were nearly due for annual maintenance, which meant the filter was coming off the engine anyway. The increment to change the sensor was relatively small. When trouble shooting intermittent problems, we tend to do the easy/cheap fixes first. In this case it worked – no more alarms after several hours of running various speeds in both calm and choppy waters.

Good luck!

 

[Sweet_Pea]

Thanks for the info, Lenny & Louise.

We consulted a Volvo service partner who agreed it sounded like the fuel sensor was faulty. Evidently, it's a known issue with our engine model. Fortunately, it was covered under our 2-year warranty.