I’ve cruised on sail and power boats for the better part of 20 years, and in that time, I can say I’ve developed a tender relationship with diesel engines. There were times when things were running smoothly and all was bliss while motoring up a long fjord in Alaska. Or when the wind shut off on the Pacific Coast of Mexico and the engine was needed, and we plodded along with dolphins playing at our bow.
There have been other times, though, where diesel engines have been the bane of my existence. It’s those times – when they have failed – that still haunt me. Those failures live rent free in my head, but I’ve always wanted to learn more about how to take care of an engine to keep it running smoothly. With each stumble, my persistence to be better at maintaining them only grows.
On the Grand Soliel 39 that my wife and I have owned and cruised on for more than 12 years, we’ve had two power plants. The first was the original Perkins 4-108 that was installed in 1984. When we bought the boat, it still had life in it, but we knew that we were looking at a full rebuild or the need to repower at some point in the future. As most Perkins do, it leaked oil, and over time it just seemed to lack the pep that it once had. Sure enough, and mostly caused by a failing relic of a sail drive, we replaced it with a shiny red Beta 50 in Alaska in 2018.
From Alaska, we sailed (and motored) south to California, Mexico, El Salvador, Nicaragua, Costa Rica and Panama, and had almost zero issues with the engine. It ran like a top. Then, after transiting the Panama Canal and heading into the Caribbean, we started to have issues.
First, the water pump failed, which allowed seawater to get into the oil. We fixed the pump and flushed the oil several times. Problem solved and everything seemed to be good.
Then, while in Colombia, the engine didn’t get as much use as it had in the previous years, while we worked remotely and traveled inland. Before sailing farther east, I flushed the coolant and filled it with the same color coolant, which I had purchased from a chandlery in Santa Marta. After sailing to Aruba and then Curaçao, we put the boat on the hard for hurricane season and an extended visit to travel and see family in the U.S.
When we returned to the boat in Curaçao, the engine was hard to start and I noticed corrosion around the cap for the heat exchanger tube stack. Upon further inspection, the metal around the cap and inside of the heat exchanger was badly corroded. That necessitated that we replace the heat exchanger.
I wanted to know what had caused this. The lead mechanic at the yard in Curaçao said, “I’ve seen this before, where did you get the coolant that’s in the heat exchanger?”
When I answered, “Colombia,” he instantly knew. I had purchased an inferior coolant that caused a chemical reaction that led to rapid corrosion of the metal. So, the engine sat even longer while we took care of that issue, and by that time it hadn’t been run in nearly six months. After the new heat exchanger was installed, the engine still didn’t start very easily, but it would start. So, we sailed on for Puerto Rico and then the Virgin Islands. About a month went by, and the engine was now impossible to start. I was a wreck. What was happening?
In the British Virgin Islands, we had the engine assessed. There was deep corrosion inside the engine block and valves, and a lack of compression. Additionally, our fuel was contaminated with algae. The only things to do were to take out the engine out and have it rebuilt. We also had to cut open the fuel tanks, clean them out and install inspection ports. This was all a massive undertaking.
The engine is back and running smoothly now, and I’m determined to not let those issues happen again. After nearly two years of chasing and fixing problems, here’s what I learned that can hopefully help you avoid the same fate.
Take Care of Your Fuel
When our fuel tanks were being cleaned, the tech was pulling out handfuls of black algae and sludge.
Hindsight is always 20/20, but if I ever buy a used boat again, I would take a hard look at the fuel tanks. First, I would have the fuel inside of them removed and polished. I’d have the tanks cleaned and then inspection ports added for each baffle, if they don’t already have them.
Once clean fuel has been put back in, it’s recommended to use a treatment to remove water and to kill algae. Water in the fuel can seriously damage the injection system. Then I’d add another treatment that prevents sludge, conditions oil seals to prevent leaks, provides a high degree of thermal stability, helps maintain the proper level of compression and power and more.
From the fuel tanks, it’s time to look at filters. We have two Racor filters that operate independently of one another. I was diligent in changing them, and will be more so in the future. Make a note in your maintenance log of your engine hours when you change your primary and secondary filters and stick to a schedule. The number of hours run is different depending on the engine.
Another factor to take into consideration is where you are getting your fuel. If you are getting it from the same fuel dock every time, you’ll have a baseline of the quality that you’re putting into your tanks. In our case, especially while cruising through Central America, we were getting fuel from various sources and didn’t always know how clean it was. In this situation, you might consider a Baja filter when refueling.
Take Care of Your Oil
Similar to our fuel filters, I have always been diligent about changing the engine oil on schedule. When water mixed with the fuel due to a blown seal at the water pump, I should have started changing the oil more frequently to make sure that all the moisture had been removed. It can be hard to tell, but changing it more frequently will help ensure any contaminants are truly gone.
This probably goes without saying, but use a high-quality oil and know if there is a certain type that is recommended for your brand of engine. Engine oil quality should have the minimum properties of the American Petroleum Institute (API) classification CF. Typically, SAE 15W-40 mineral based multigrade oils will meet this requirement.
Do not overfill the engine oil and never mix two types of oil. Depending on how you drain your engine oil for changes, try to get as much of the old oil out as you can before adding new. Cutting open your oil filter to check for contaminants is a good idea.
Don’t Let the Engine Sit
Letting your engine go long periods of time without being started can be death. When we let our engine sit for many months in Colombia and then Curaçao, it allowed the unknown start of corrosion to proliferate and become a huge problem. After chatting with several mechanics and doing some research, I learned that it’s ok to leave your engine for a few weeks or even up to three months. After that, it’s a good idea to have someone start the engine to keep everything lubed and working smoothly.
An alternative is to “pickle” your engine, which is sort of a last resort. This is an old-school term, but what you’re basically doing is filling the engine with oil or diesel to make sure that most of the internal parts are receiving lubrication while the engine sits. Consult with a professional and/or your engine manufacturer before doing this, but it can be done.
No matter what you do, remember that diesel engines like to be run at load. Idling for excessive periods isn’t great for them, so when you do start it, take it out of gear and rev it up to 1,200 to 1,500 rpm. Your engine will thank you.
Don’t Overcrank It
This was a big point to learn for me. When our engine was hard to start, I would crank and crank and crank to get it fired up. According to several mechanics we worked with, by doing this, we were likely forcing seawater into the engine through the exhaust system. The remedy for a hard-cranking engine is to close the raw water sea cock when cranking and then immediately open it once you get it started. I had always been taught to make sure the sea cock is open when starting, but in this instance, closing it makes sense.
Along with the raw water and exhaust systems, make sure to check and change your impeller at regular intervals. If any of the rubber impeller blades are missing, they’re likely in the heat exchanger cooling stack.
Just like with other fluids, make sure to stay on a schedule with flushing and adding new coolant. Only use high quality coolant and do not mix old and new or two different types.
A Couple More Points
Other major things to stay on top of on your engine are the electrical system and the air intake. Unlike some modern diesel engines, ours has no major computer that monitors the engine. It’s pretty simple. Every so often, I make sure to check the wiring connections to the starter and alternator, start battery and the wiring harness to the control panel. If there are any signs of corrosion, they need to be cleaned and greased. If you have a more technical engine, you might have a certified mechanic take a look once a season.
The air intake is fairly simple. Every engine needs air to run, so check your filter and replace on the manufacturer’s recommendation. Also, check to ensure there is nothing near the air intake that can cause normal air flow to be inhibited in any way.
Takeaways
All of the above is what I’ve learned and observed over my time using and maintaining diesel engines. I am by no means a mechanic. But I’ve clearly had to work on my engine many times over the past few years, and in doing so, have come away humbled.
My biggest points of emphasis and conclusions are that, when you’re cruising, particularly in remote areas, maintenance is solely up to you. While I thought I was doing everything right by staying on top of the general maintenance items, I could have done more and should have seen some warning signs. Overall, I know how to take care of and feed my engine better now, which is all I can hope for moving forward. n