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Hanging Out in Anacortes

Since we got back from Sucia Island on Tuesday, we’ve just been hanging out in Anacortes doing some boat projects and some other work. We changed the oil and filter, changed the fuel filters, changed the impeller…we’ve still got a windshield wiper to replace as well as the engine zincs and maybe the transmission fluid…just doing the regular maintenance projects. It’s nice to do these things after the big summer Alaska trip instead of before, so we’ve got time while boppin’ around the San Juans to make sure there are no maintenance-induced problems. 🙂

When we went to Sucia on Sunday (our first outing since getting back in the water), we noticed our engine (a Yanmar 6BY3 260HP) temperature was running a few degrees hotter than normal, and when we throttled back as we went into the Matia Island anchorage for a few minutes to check it out, the temp rose up another couple degrees before going back down to normalish after we were back at our regular cruise RPM. Same thing on our way back to Cap Sante, so I cleaned the sea strainer where the raw water comes in from outside to cool the engine in case it was clogged (it wasn’t…there was pretty much nothing in there) and we changed the raw water impeller just in case it was starting to fail (it looked good other than one tiny crack at the base of one of the veins). We haven’t had the chance to run it again with new impeller, but we’re fairly certain nothing else has changed in the system, so it’s a little curious why the hotter temp. No alarms are going off, but when things are consistent over a long period of time and they change, even slightly, I like to know why they change. (Update below.)

In the meantime, Kevin went to San Jose to give a keynote speech for one of our clients, and I got a bunch of work done here at the boat. It’s been windy and rainy until today, and so today, I took advantage of the gorgeous weather and went for a nice long walk.

This is the trail that goes out to the point here at Cap Sante:


Some great trees here on this trail (and a whole bunch of fresh dill!):


This is looking toward the breakwater and the entrance to the marina:


If you zoom in, you can see the rough water flowing in through the two jetties:


Great day to go sailing! There was about a 20 kt wind…sky clear, sunny and gorgeous. Tough to be here working while the sailboats kept going past. Pesky sailors! 🙂


The forecast through Sunday is supposed to be pretty windy, so we’ll likely stay put until we head to my mom’s on Sunday (unless things change for Saturday and we can sneak out for a bit).

Update — news on the temperature mystery! It was an easy one, too, which is nice since that isn’t always the case. A little over a year ago, we had a very minor coolant leak (tiny amounts of coolant were showing up in the bilge). We had the shop take a look at it, and they found and fixed a leak at a hose clamp. After that, the engine temps seemed normal and stable, and the coolant overflow reservoir was consistently about half full. Then, recently, as we mentioned above, we started noticing that our temperature was running a few degrees higher at cruise than before. Looking at the overflow bottle, the coolant level still looked good. Raw water flow seemed good but we replaced the impeller anyway. We realized (in the middle of the night the other night) that we hadn’t checked the coolant level in the engine itself. So in the morning, we got up and…surprise! We were able to add a fair amount of coolant to the engine. So apparently, when the repairs were done to fix the leak, no coolant was added to the engine itself…they had just added to the overflow reservoir, and because the engine runs at such low and steady temperature, with the air gap there wasn’t enough expansion and contraction to move fluid back and forth to the overflow. With the coolant topped off, we took Airship out for some testing. At our normal cruise, we were showing 3-4 degrees cooler than our normal temps. So not only is the issue fixed, we’re running a little cooler now, even.

Moral of the story: Know your baselines, and pay attention when something changes. And don’t depend on the overflow reservoir to give you all of the information you need about your coolant. There are lots of reasons it could be wrong: faulty pressure caps, leaky hoses, etc.


  1. Amy and I miss ANACORTES!

    • It’s SUCH good home/boat base!! Hope you guys are having fun travels!

  2. Glen Glen

    Regarding the engine temp issue, I had a similar issue with my Volvo, turns out that I had a wad of eel grass (it managed to get through the strainer) plugging the first heat exchanger in the cooling system, which on my engine was the transmission heat exchanger. It was an easy fix, simply removed the raw water coolant hoses from the exchanger and back flushed it with fresh water.

    • There’s no way that eel grass could make its way through our sea strainer. That’s amazing…glad you found it!!

  3. Casey Adams Casey Adams

    A few tips for you on the engine temp problem. Unfortunately, I’ve had a lot of experience with this issue garnered the hard and expensive way.

    Once you’ve eliminated the more likely problems such as impeller, sea strainer etc here are other things you can do. Inspect the entire raw water path including at high rpm. If you see any of the hoses bulging that indicates a blockage downstream. One time I had the return fuel cooler implode on itself (for reasons no one has ever been able to explain) which then severely restricted the water path causing a partial blockage. The hose directly upstream would bulge out under higher rpms.

    Also, if you’ve ever had an impeller break up then pieces of the impeller will flow downstream and can lodge someplace where it will restrict flow. Also, pieces of the zincs can break off and flow downstream causing blockage. And, there are lots of other reasons you can have blockage somewhere along the path. On my genset they originally used cast iron exhaust elbows which of course eventually corroded out. The corrosion would partially block the water flow causing overheating.

    It may also be either the engine temp sending unit, or the gauge itself. I’ve experienced both. Also, it’s possible that you’ve sucked something like a plastic bag into your raw water grate intake.

    After the relatively easy steps above If you can’t identify the problem then unfortunately the next step is disassembling the components along the path of flow inspecting and cleaning them while looking for a blockage. Unfortunately this is a very big job and takes several days for my main engine. It is actually part of the normal scheduled maintenance procedures on most engines for the biggest scheduled service which is at 4000hrs on my engine although I’ve had to do it more frequently than that and it’s amazing the stuff you can find in there!

    Finally, If your engine doesn’t already have an exhaust temperature sensor alarm I highly recommend installing one. Many of the newer engines come with them, but mine didn’t. The problem is that by time you realize that an engine has overheated by the normal coolant temp gauge and/or alarm the engine is likely damaged since it takes a little while for the coolant temp to raise. However, the exhaust temperature will rise instantaneously and allow you to shut down the engine before it gets damaged. Also, you can simply aim an infrared heat sensor at the exhaust elbow and read the temperature directly which allows you to easily determine if the sensor or gauge is malfunctioning.

    Also, one comment about your comment about doing oil changes early before the cruising season. I totally get your point about trying to avoid changes near or during the cruising season as I’ve had what should have been very simple repairs escalate into major issues if something goes wrong. I steadfastly avoid even the simplest repairs while cruising if I can live with it until I get home.

    However, on oil changes there is an important time factor involved. All the manuals say change oil after XXX hours or 3 months whichever comes first. I never really understood the 3 month thing and wondered if it was truly necessary. So, I thoroughly researched this issue. The fundamental problem is that you have condensation inside engines just as you do inside your fuel tanks for exactly the same reasons. This condensation finds it’s way to the oil pan where it mixes with the oil effectively diluting the oil, and therefore reducing lubricity. So, it’s important to change every 3 months regardless of engine hours.

    I change oil on all engine shortly before leaving for Alaska allowing enough time for a couple of small shake down cruises in the San Juans before leaving. I also collect an oil sample from each engine which I send in for analysis and takes about a week to get the results. This can give you an early warning if something is going wrong inside the engine.

    • Re: the oil changes and time factor, don’t worry…we’re not THAT new (and we have owned airplanes, which require much stricter adherence to maintenance schedules…so we come from a very good background of responsible maintenance schedules). We adhere to the recommended timeline for oil changes and also do oil analysis with Blackstone Labs after every change. (I meant more overall doing maintenance projects not always right before leaving on a big trip, not specifically oil changes….since we do those even DURING our summer trips).

      Thanks for the tips though.

      • Casey Adams Casey Adams

        Oh btw, I just remembered the only possible explanation I’ve heard for the fuel cooler imploding. It was speculated that at some time the return fuel valves at the tanks were closed, or partially closed creating back pressure that stressed the sleeve inside the cooler. In any case, i’ve had other problems from valves getting bumped and partially closed. For example, one time the autopilot stopped working and I discovered that I had bumped one of the valves on the hydraulic lines to the pump. So, now I use releasable zip ties on all valves in engine room so they are basically locked open and it’s easy to remove the releasable zip tie if I intentionally want to close it.

  4. Kevin McLaughlin Kevin McLaughlin

    Those minor fluctuations in coolant temp! For some unknown reason my yanmar 3gm30f stays at a cool 160, but every once in a while goes to 170. Maybe the temp sender is wonky?

  5. Hi all: I updated this post yesterday with our temperature issue cause…in case you’re interested. It was a nice, easy fix! Woohoo!

  6. GMertl GMertl

    I think that’s why I love boats. There’s always a new challenge and always something to do ;). Gotta admit it’s a good feeling to find an fix those little problems.

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