The wind had dropped to under 5 knots so it was time to turn on the diesel – or on a sailboat, the auxiliary or iron genoa. We’d used the diesel for two days down the Columbia River, from Portland to Astoria, where we refueled adding 40 more gallons to the tank.
But, we are now 40 miles off Newport Oregon in light winds, not enough wind to sail, so we are motoring. It’s one of sailings dirty little secrets. When the winds are too light to sail, we motor.
Diesels are notoriously fickle about the quality of fuel they use. Even letting good fuel sit for a year is enough to turn good fuel into bad. Up to 27 different types of bacteria thrive in the water vapor that diesel fuels absorb over months or years. Eventually these “bugs” die and leave little carcasses that drop to the bottom of the tank setting there waiting to be shaken back into the tank and cause havoc as they are sucked into the engine. Diesel injectors are built with extremely fine tolerances so they clog easily if the fuel is not very clean. To prevent clogged injectors there are two very fine filters. When bug carcasses exist, they plug up either or both of the two fuel filters (1st one is 10 micron – it’s made by Racor; the second is 2 micron- it’s made by the engine manufacturer) they are in series. When we headed out to sea, the sea saw to it that the tank was shaken. It was 2AM when the engine quit.
But we knew all about bugs. Before leaving, we had the fuel in the tank cleaned and our fuel tank walls and bottom cleaned and scrubbed, a practice known as “polishing”. Unfortunately the tank has a baffle that prevents thorough cleaning behind the baffle wall. We were pretty sure the fuel was clean so the engine shut-down was a mystery.
But we did not know about the quality of the fuel we added in Astoria, so I changed filters on the spot. We keep a large number of both filters on board just for such occasions.
However as I replaced the 1st filter, the Racor, in the dark of the morning, it looked clean. The second filter is metal so I can’t tell if it’s dirty.
The engine ran perfectly, for about an hour then quit again the filters were changed again – this time the engine ran for five minutes. There was no wind, so this is a concern. We aren’t in any immediate danger, we have lots of food, water and candy, the seas aren’t rough, but we are stuck in the dark and it’s an unsettling feeling.
We tried starting again and it kept going. We found that by carefully listening to the engine RPM we could detect the engine faltering and would immediately turn on a little auxiliary intermittent duty electric fuel pump. Doing that kept it running. We both became finely attuned to listening for that slight change in engine noise and ran for the pump switch immediately, sometimes both reaching the switch at the same time. But it kept going, until it didn’t.
We got to the port of Charleston, Or. during the evening of the next day (another long story). Charleston, near Coos Bay, is a down on its luck fishing village with lots of character and lots of characters as well.
The next morning we left a message for Ed the local diesel mechanic. The message was not returned. Hours later I walked to his shop where he explained he was tied up with another job and could not predict, even to the week when he could get to our boat. But he did ask what Cetacean (our boat name) meant. It’s not a question I get often and I get excited when I hear it. I’ve come to equate that question with curious people and curiosity implies some intelligence – it was enough of a straw to hang on and wait as long as it took. And that’s not easy when a grandchild is about to be born. It could have been weeks. I’ve dealt with some mechanics is far away ports that know we are not repeat customers so we get a low priority. I didn’t know about Ed.
That was on Monday morning, on Friday morning Ed called that he was free.
Here is what he found: Little air bubbles (like pinhead size bubbles) were rising from bottom of the Racor fuel filter while the engine ran. They collected like invisible ghosts at the top of the filter slowly displacing the fuel downward where eventually the engine can’t get suck it up and that’s when it would die. When we turned the electric pump on it forced fuel back up keeping the engine going. But air kept accumulating so the fix became less effective and more random over time.
After lunch, Ed came back to the boat to diagnose the problem – to find why air was entering the system, we knew it was air but why? – it’s never as easy as: ‘well its just a leak’.
The fuel pump (also called a lift pump) sits on the engine and ‘sucks’ the fuel from the tank causing a vacuum. If something were blocking the lines, vacuum would get larger ( to get any fuel it had to suck harder), if the vacuum got really large it would suck air from places that are usually sealed, like at the Racor filter.
But just as we set out to diagnose the problem, our little electric fuel pump – our little helper pump – the one that got us through the night, the one we tried just before lunch, refused to work -it had just quit. Gremlins had played their devilish evil on the pump just at the moment we needed it to help find the problem. During normal motoring that pump is not ‘on’, its only there when filters need to be changed, but the fuel goes through it, nevertheless.
Ed turns out to be a very personable, with a lively intelligence and wearing a Cycle Oregon t-shirt under his coveralls. He is trying to sell his business to retire; and after 40 years in the business he deserves it. In spite of the rough beginning I liked Ed. He is able to explain the issues, why things work or fail to work like few mechanics can. He is literate and articulate. But Ed has to get a new electric helper pump.
Ed replaced the pump and replaced a gasket on the fuel filter so when the engine stared it purred and no air bubbles were to be seen.
We left the next morning for what turned into a 24 hour sail (with lots of rock and roll) with minimum motoring but when the motor was need through the breakwater at Crescent City, Ca and during docking it worked perfectly.
The next day Ed called. He’d been paid ( the bill was very fair) so there was no particular reason he had to call. But he had taken our old electric pump apart and found a screen built into the pump (not a usual place for a screen). That screen was completely clogged with a layer of powder (not bugs) and almost completely blocking fuel flow. So now we knew the whole story. The screen caused the lift pump on the engine to work so hard it sucked air in places usually sealed.
Without our gremlin, we may never have replaced the helper pump, not fixed root cause. You be the judge did we have a malevolent gremlin or a helping maybe kindly one. Where the ghosts and gremlins helping us along this time or are they laughing their silly little heads off from another world at their perfect joke? We may never know.