15 July 2007 | Rodney Bay Marina
So Hideko and I were enjoying the air conditioning, I was working on the computer, the stereo was going, and then, zap! Everything just shut off. The DC side of the house was still operating but everything AC was dead. This is a rare occurrence, usually caused by an over current condition popping the main breaker. This time an eerie silence accompanied the outage.
The genset was actually shut down. I walked around to look at the coolant temperature and saw that it read 210 degrees Fahrenheit, not good since water boils at 212. Normal operating temperature was 160, luckily the Westerbeke has an over temperature shutdown. We always check the water flow when we start up any of the diesels, so I couldn't imagine the impellor was broken, yet that was the only heat related thing I knew how to fix, so I was hoping it wasn't something else requiring arcane Genset knowledge.
I opened up the engine room and took off the sound shield and heat filled the room. I closed the raw water seacock and checked the impeller. Mangled would be a fair description. I used some needle nose pliers to rip a couple of impeller vanes out of the hose leading to the heat exchanger.
Our Westerbeke has been flawless in every way except this one. It provides 220v to the dive compressor, powers the 110 house on two legs with a 100 amp charger, computers, Home Theater, two large AirCons, a hot water heater, ice maker, washer dryer, all concurrently. You can even fire up the microwave if you're careful, though this is the one device that might require us to shut off an AirCon for a few minutes.
Some engines just go through impellers I guess. Both of our Yanmars have more hours than the Genset and neither has ever needed a new impeller. This is the fourth one the Westerbeke has needed. Fortunately I restocked in Saint Martin.
I recorded the engine hours in my maintenance log and noted that the meter read 505.3 hours. Five point three hours overdue for the second 250 hour service. The Diesel Maintenance god has no sense of humor. Seeing as how a 250 service is probably wise after overheating your engine anyway, I set about it. Aside from some really tough to fit on and get off fuel filter bits the 8BTDA is easy to service if you have an oil pump. I have a little Jabsco pump that comes with its own reservoir that I bought in Saint Martin. It works well and allows you to pump the oil out where the dip stick goes. It is also the only way to change the sail drive gear oil without hauling the boat.
The Westerbeke (official Westerbeke) replacement impellers fit into the housing fine. However, the impellor has a screw that goes through the center of the rubber bit, which fits into a slot in the pump's drive shaft, ultimately turning the impeller. The replacement impeller screw is threaded all the way through. The installed screw is only threaded on the ends, having a thinner bar in the middle. Thus the replacement impellers don't fit into the drive shaft slot. Reusing the old screw is working so far but I am concerned that one day it will go down for the count as well. I have inquired about this matter via messages on the Westerbeke web site several times but I get no response.
The coolant overflow tank hose melted through in a spot so I had to find a replacement. Fortunately there's an Island Water World right here in Rodney Bay. I purchased a much sturdier fuel line hose for the job. While connecting the new, higher heat rated hose the reservoir cracked. Lovely. I searched for a part at various places but nothing fit the bill. Finally, on Fred's advice, I just coated the bottom of the old tank with silicone. Magic.
Well that was an unexpected ordeal. We will be keeping a much closer eye on the genset temperature gauge. Although my Yanmars have never let me down in this or any other way, the experience has made me wish that I had the C Type control panels with coolant temperature and oil pressure readouts for the Yanmars. We have the B Type panels which only have idiot lights (applicable or not).