Pumping the used oil out of the engine – believe it or not, this is actually very good engine access for a sailboat
Keeping a cruising boat in good operating condition is a never-ending job. The corrosive saltwater environment is continually trying to eat away at the boat, and the cyclical loading caused by sailing in waves tests all of the fasteners aboard.
We try to counteract that by working on a couple of projects a week, often spending a few hours on maintenance in the morning before doing something more fun in the afternoon – surfing, or snorkeling, or exploring ashore. This week’s projects were dedicated to the engines on board, both the main engine and the outboard.
Pouring fresh coolant into the engine after a change
Madrone’s primary engine is a Yanmar 4JH2-TE – it’s a turbocharged 4 cylinder diesel. It’s been ultra-reliable, starting every time we’ve asked (as long as we haven’t accidentally shut off the fuel valve, that is!) and running continually for up to 50 hours without complaint. To help keep it this way, we change the oil every 150 hours of run time. It’s normal for diesel oil to turn black over time as combustion byproducts find their way into the lubrication, and the oil in our Yanmar has just become dark when it’s time to change it again.
Diesel engines are fairly simple, and they’ll generally run well as long as they have clean air, clean oil, and clean fuel. Since the engine is located on boat where things like road dirt and dust are minimized, we don’t have to worry too much about the clean air – we just make sure that the air filter is not too dirty. For the clean fuel part, we have both an external Racor 30um primary filter and an engine-mounted 5um secondary filter. We generally change these at least once a year (or every 500 hours of run time, whichever comes first). The fuel filters have always looked very clean when we’ve changed them, likely because we’ve also done a good job of keeping the fuel tank itself clean.
Pulling the water pump out of the outboard lower unit
All marine diesels need a way of dissipating the heat of combustion, and ours works via a reservoir of liquid coolant. An impeller pumps seawater through one side of a heat exchanger, while a second pump circulates coolant through the other side. Since the coolant side of the system is completely closed, we only need to change this coolant every couple of years.
All of this came due at the same time, and we spent a hot, sweaty day deep in Madrone’s engine compartment.
A new impeller, and the engine is back to spitting plenty of cooling water
Of course good things come in groups, and our outboard also started not circulating as much cooling water as it originally did. So, off came the lower unit of the outboard for an investigation, and ultimately, a change of the impeller in the cooling water pump.
Hopefully, the engines will be in good running condition for a while now!
