muffler

[Mewes]

At the end of next month Island Yacht Club's annual Women's Sailing Seminar features a session on Diesel Engines. The whole program is pretty informative, take a look.

http://www.iyc.org/wp/wss/2013-wss-class-descriptions/

Led by really accomplished sailors, too.

Lucie

[Philpott]

I have learned how to check the water pump's impeller. That was working fine. What caused Dura Mater's engine to overheat was that the thermostat was corroded shut. Yup. And so today I spent 1.5 hours contorted in my port lazarette while I unscrewed the old thermostat. I did it by touch since it is obscured by pesky engine parts and wiring and etc. Yikes. The conclusion (by all) is that it is probably the original thermostat and it is a good thing I discovered it now. Yeah, right. I wish I'd discovered it in the bay instead of offshore in the dense fog (if I'm looking for sympathy from this crowd I know I won't get it), but that's just the way it goes sometimes.

[Philpott]

That's the lift can - it cools the exhaust before sending it out through the exhaust hose. The impeller is on the water intake side - it pushes the water into the engine..

I bought a new one and installed it. On Wednesday, returning from Clipper Cove w my friend Jocelyn, I realized that no water was coming out of the exhaust. Turned off the motor, floated with the flood into the Berkeley marina and my slip on O dock under sail. It took 2 hours, but it was a lovely balmy night. We decided to call it an adventure, though when the smoke billowed out, she was keen to use the fire extinguisher. The flange on my (new) Vetus waterlock melted. Now I'm thinking that my engine woes might be due to a clogged/dirty/malfunctioning heat exchanger. Who knew I had a heat exchanger? The manual knew. So today that's what I'll be doing. Finding it, removing it, and looking it over. Monday I'll meander over to the Berkeley Marine Center. I'll sit outside on the bench holding it and several people will give me several different bits of advice. Sort of like this forum. O Dock Slip 212. I have strong coffee capabilities on board.

Later: Can't find anything that looks like a heat exchanger on my boat. Universal M15; should be there, yet it is not. Any thoughts?

[BobJ]

It's sea water cooled like my Yanmar 1GM = no heat exchanger. See the link. Most of the time you'd be right though - most are fresh water cooled.
http://www.marinedieseldirect.com/un...fications.html

Your new impeller might have had a problem. I had one where the metal core separated from the rubber part and it was spinning but not pumping. Since you've had it out before, take a look at it. Without cooling water, the engine probably got so hot it melted the flange on the plastic lift can.

I'm really, really sorry about your engine problems. I hate engines.

[Philpott]

Thanks, Bob. Please note that on the bottom image you sent it includes and refers to a heat exchanger. What's all that about? There is nothing like that (nothing!) on my engine. I know because I just crawled out from under my cockpit to take another look. I am so grateful when my engine runs ("oh thank you!thank you!" I say to it.) When it does not, I am grateful that I can raise my sails because YES! I have a sailboat. And I never NEVER sail near a lee shore from which I cannot sail away.

[BobJ]

So it does - I just looked at the list at the top and saw "Sea Water Cooled" in the right-hand column.

[Critter]

One other possibility, Jackie: I assume your engine is of comparable age to mine (1980 Volvo MD7A). My water pump was getting so worn (i.e. clearance around the impeller) that it wouldn't generate enough suction to prime itself and start pumping. A new impeller didn't help. The last couple of times I sailed, I had to disconnect a water line and fill the system from the dock hose while the engine was running. Then I could shut it down and it would pump water if I restarted the engine a few minutes later. But at the end of the day, coming in to the slip, nothing.

Over the last couple of weeks I disassembled the pump, machined the bottom of the impeller chamber flat, and machined an equal amount off the sealing face to keep the depth the same. I also installed new shaft seals. Saturday it went back on the boat and - after some worrisome dry running - it started gushing out the exhaust. Gushing, I tell you! Very satisfying.

So a new or rebuilt water pump may be what you need. If you take out the impeller and can see or feel irregular wear in the back of the chamber, I bet that's part of your problem.
Max

[Philpott]

That word: Gush. I long to see it. Sadly, I have a brand new shiny Oberdorfer pump. I'm thinking it might be that my water strainer (very cool, very old bronze perko) had a leak so there is no pressure. Having spent 4 hours below deck on Friday removing it and checking all the hoses, I removed that also. Again. Next I'll go to Svendsen's for a modern strainer. Did I mention that I checked all the hoses? There are a LOT of hoses between the thru hull and the exhaust in the back, all in very inconvenient places. When you say you had "some worrisome dry running", how long was that? 2 minutes? 5 minutes? For how long were you worried? Because my engine runs great. I just don't want to burn it up while testing it. And I'll check that impeller again, too. Thanks, Max!

[Critter]

When you say you had "some worrisome dry running", how long was that? 2 minutes? 5 minutes? For how long were you worried?

At least 5 minutes. After the last South Beach race, I started it outside the marina when we were ready to drop the main, and we got into the slip without the alarm going off. And I could hear the exhaust echoing in the dry muffler. Saturday, after installing the pump, I ran it longer but I could hear some gurgling and there was an occasional feeble spit out of the exhaust. So it wasn't totally dry. I think my Volvo is a big lazy hunk of cast iron, and it doesn't get hot very quickly.

[Philpott]

That is very helpful, Max. Thank you. I'll try the hose directly into the engine first to isolate the problem. If water comes out of the exhaust I'll work backwards. I'm thinking it must be the water strainer seal. Five minutes. Wow. That's a scary long time. Terrific to hear that the issue has been resolved for Solar Wind.