It felt like a graduation day. Everything really worked the way it was supposed to.
The most important thing was a certain lack; a missing gall or burr; an absence of nagging worries.
On Sunday hosted the Previous Owners, Bob and Patty. Their life together -- marriage and three kids -- is intimately bound up with this boat. But they've moved on to other things and the boat has moved on to us. As Bob said, "It's like marrying off your daughter. She's always your daughter. You really want to be sure about that son-in-law." Boat-care aside, it was great to visit with them in general because they're truly delightful people. It was helpful to get a few of the remaining little questions answered. Better than that, they love the water, their kids are just a little older than ours, they love the Caribbean, the list goes on.
We drank a toast to "Stewardship". This boat -- with care -- will outlast all of us.
Stewardship is work. In our case, the engine had over-heated. Good stewardship means diagnosis and repair. The good news is that there are checklists for this. The bad news is that there are also some usual suspects. We should be organized and follow the checklist. But instead, we're just going to prosecute the usual suspects.
The diagnosis checklist is -- frankly -- tedious. Nigel Calder (Boatowner's Mechanical and Electrical Manual) gives a half-dozen or more reasons why a diesel engine might overheat. The Ford Lehman owner's manual gives four major areas to check.
What's important here is the fact that boat engines don't have radiators.
FAQ: If there's no radiator, where does all the heat from a 254 cubic inch, 80 horsepower cast-iron monster like Mr. Lehman go?
Answer: Into the water via "heat exchangers": a piece of plumbing that brings raw water and engine fluids into close contact so that engine heat is transferred to water that's -- eventually -- blown out the exhaust pipe. There are heat exchangers for transmission fluid, oil and engine fresh water.
If we stepped through the list as we're supposed to, we would see the following. On the fresh-water side, (a) the belts are solid, and (b) the hoses are fine. So we might have to replace (c) and (f) the thermostat (we have three spares). I think that replacing the thermostat means draining and replacing the fresh-water coolant. I'm not eager to do this, but, if Mr. Lehman continues to overheat, we'll do it. Some folks recommend pumping the coolant out, since there's no easy way to get a bucket down there and we really shouldn't drain it into the bilge.
For item (d) (air in the fresh water side), Calder's suggestion is to crack open the hose that runs between engine and hot water heater and bleed out any air. Instead of that, what I actually did was to replace the filler cap with a brand new one. That was simpler than trying to burp air through the water heater connection.
The official bleeding procedure seems simpler than burping the hot water heater lines. Maybe I'll do that next weekend instead of just going sailing. That would be the right thing to do.
That leaves us with (e) a clogged heat exchanger. A horrifying situation what requires removing and replacing a nearly inaccessible part. Hopefully it doesn't come to this. I've read about people running garden hoses down into their engine room to flush water backwards through their heat exchanger to force out any crud. I've also heard of removing the covers and forcing wooden dowels through to push out the crud. And I've been reading about removing them and soaking them in acid to dissolve the crud.
From the sea-water side, (a) our strainer is easy to check (and clean), (b) our scoop is present, and (c) our sea cock is open. For (e) (clogged heat exchanger) see the comments above: we're a little intimidated by taking the engine apart to soak parts in acid or to force a dowel through the heat exchanger tubing.
The other two items are off the list of potential problems. We have oodles of crankcase oil (8 quarts, checked every time we start Mr. Lehman up). Injection timing is unlikely; if the timing is wrong, it won't even start.
The Usual Suspect
Item (d) on the sea-water side "Water pump impeller damaged" is the usual suspect. This is a chronic nightmare problem, reported by many, many boaters. The issue -- I guess -- is that it's a painful job to get the little bugger out of the water pump. In many engines, they're nigh-on inaccessible. We, however, are blessed with an engine room ("Mr. Lehman's Office"), so it isn't that painful a job. It requires a little patience and a 90-degree screw-driver.
Once you've got the cover off the water pump, you have to dig the impeller out. Apparently, Jabsco, inc., says that you're not supposed to use screwdrivers to wriggle it out. You're supposed to buy a $90 impeller puller. Right.
After you dig the thing out with screwdrivers, you can examine it for (1) missing vanes or (2) damaged or worn or permanently-bent vanes.
I'll vote for permanently-bent vanes. This can limit raw-water flow. Which can lead to overheating.
From the Previous Owner's maintenance log, we think that this impeller has been in there since something like '03. The vanes appear to have taken a "set" over the last seven years and become permanently bent. The good news is that they aren't broken -- I don't have to search for bits of rubber crud jammed in one of the heat exchangers.
Not On The List
There are some things that are not on the standard list of suspects. A failed head gasket can allow cooling water to leak into the engine. This shows up in the oil. So far, the oil is sparkling clean. So the gasket is okay. Another possibility is a failed heat exchanger that's allowing freshwater out of the engine through the heat exchanger. There's a small possibility of this, but usually it leads to catastrophic and immediate overheating, not overheating under load.
After spending Saturday on the engine work, and Sunday hosting the previous owners, we feel like graduates. Monday could have been a day to finish the mainsail stackpack, plug some holes in the deck that are only potential leaks. It could have been a day to start looking at the tachometer issue, or we could have started replacing the lifelines.
Instead, we went sailing.
The wind was 10-15 from the SE with waves of 1-2'.
We played around with the main under one reef and learned that she doesn't handle well. We could not get her to tack. At all. I think there's too much twist in the main, spilling too much power. It could be that the reefing line is be too far aft. Or, the leech tensioning cord is loose. Most likely, the topping lift is interfering with the main sheet pulling the and of the sail down to remove the twist.
After we shook out the reef, though -- whoo-hoo! -- she flew. Under main and yankee, she's a well-mannered boat. She tacks slowly, but gracefully, she's unperturbed by gusts.
We never got out of the mouth of the Piankatank. Our iNavX track on the iPhone showed that we went all of 5.6 nm in big loopy circles around the river. A short but glorious sail.
One of the most glorious features was the complete absence of serious "we should be doing jobs" considerations. The serious jobs are -- mostly -- behind us.