Will it ever end?

[Baltimore Sailor]

After giving my A4 a 2 1/2 hour shakedown cruise on Wednesday with nary a problem but having to make a quick adjustment of the shifter cable turnbuckle, I took the family out for a cruise on Saturday afternoon. Planned on sailing around from Rock Creek in Baltimore to Bodkin's Creek for dinner at a restaurant there. Events did not transpire as planned.

First off, rather than leaving around 3 PM as I'd planned, and allowing for 2 hrs to sail over, we didn't get out until after 5. Then the wind was foul for the creek (blowing straight from it), so I figured I'd make two tacks and then fire up the A4 and just motor in. As we made the first tack, my wife pointed out that the genny was torn! Just about the time I looked at it, my #2 genny split completely across. I don't know about sail repair; I hope it can be fixed/is worth fixing. I left it on the foredeck, figuring I'd put my 100 jib on at the restaurant after dinner.

Since it was getting on around 6:30 by this time I figured I'd fire up the A4 right then and just motor the rest of the way. She started right up, I put her in gear and then went forward to drop the main. Just as I'm finishing that up my wife says, "Something smells real hot!" and when I look at the engine temp it's up to around 220 and nothing but steam is coming out of the exhaust. I immediately shut off the engine, and we decided to head home.

So back to the foredeck to reraise the main, stuff the ripped genny down the hatch into the v-berth, hank on the jib and get it up. At least the wind was fair and good for home, and we made good time. Had to tack a few times to get back into Rock Creek, but the wind stayed constant in direction and force, and we were able to sail right into the creek, drop the jib, and ghost right up our row and into our slip. If the wind had been blowing into the creek instead of out, I could have left the jib up, backwinded it and used it with the main to back into the slip!

So, yet another family outing in my poor girl ends in disappointment, though I did get to show off my mad skilz to get the boat in. But still -- am I ever going to get this engine dependable? Replacing the impeller was the last maintenance item on my checklist that was I nervous about, as I had no idea what it's condition was. Now I have to find out why the water pump crapped out all together after running fine on the way out.

I'll get to figure it out on Wednesday, I guess.

[msmith10]

Was the engine pumping water when it overheated? Have you run the engine since you changed the impeller? If not, my guess is you need to prime the water pump. Disconnect the hose from the thru-hull, fill the hose with water, then, holding your thumb over the end of the hose, reaattch it to the thru hull. This should get the pump primed.

[Don Moyer]

You might also be caught up in the "new impeller in an old pump syndrome". I'm attaching a short explanation we worked through with Oberdorfer several years ago on this subject for your consideration.

On the brighter side, it appears to me that your wife and family make up a pretty staunch crew. You're very fortunate.

Don

[Baltimore Sailor]

I ran the engine on a shakedown cruise for 2 1/2 hours after changing the impeller last Wednesday, and everything was fine. It was also working perfectly on the way out on Sunday.

I'll be heading over after work on Wednesday to have a look at everything. I still have the old impeller to put back in if necessary.

When you say the new impeller "won't work", do you mean (1) it just doesn't fit back in properly, (2) or that it fits in but won't pump water, (3) or that it works for a while and then fails?

My family is a great crew... but my wife keeps asking me why I don't just put an outboard on her...

Sigh.

[Don Moyer]

The answer is your (2) and (3).

Don

[SEMIJim]

The answer is your (2) and (3).

Don

Is this a fairly common problem with original pumps on mature A4s? If so: Sounds like another good reason to replace an older pump.

Jim

[Baltimore Sailor]

I had a thought pop unbidden into my head this afternoon.

The day after all the above happened, I went to the slip just to make sure my boat wasn't sinking at the dock. When I reached down to check on the through-hull, I found that the fitting on the through-hull was loose at both ends. I was easily able to rotate the threads back and forth at the hull end, and also at the hose fitting on the other end (there's another ballcock valve in between, with a bypass fitting also).

At the time I was just puzzled: how did they get loose? Vibration? Heat? I know they were tight when I last looked. There was a slight drip from them, so I closed the through-hull gate valve just be safe until I could take more time to look at them on Wednesday.

Then today the thought popped up: what if that leak allowed air into the system, so that when I shut it off after motoring out the water leaked out of the line and the pump lost priming? That could certainly account for what happened: with air leaking into the system, there's no way the impeller could draw water into the cooling system.

I am now very interested in tightening that fitting back up and repriming the pump on Wednesday for a test.

[sunnnnseeeker]

I think that will do it!

[Don Moyer]

Jim,

I wouldn't suggest replacing a pump arbitrarily based on age. Operating hours, water quality, etc. (usually unknown) are better indicators. It makes sense to me to replace an impeller every two or three seasons (depending on operating hours), and if performance heads south on a pump that is otherwise in good condition, it's probably a good time to replace the pump and keep your new impeller as a spare.

Don

[SEMIJim]

Jim,

I wouldn't suggest replacing a pump arbitrarily based on age. Operating hours, water quality, etc. (usually unknown) are better indicators. It makes sense to me to replace an impeller every two or three seasons (depending on operating hours), and if performance heads south on a pump that is otherwise in good condition, it's probably a good time to replace the pump and keep your new impeller as a spare.

Don

Very well. Thanks, Don.

The thought was related to the (rather wordy) questions I'd asked in Upgrade Impeller Pump?. Our cooling isn't giving us any trouble, but I kinda want things to stay that way .

Sorry, BS, don't want to drag your thread off-topic.

BS, the loose fittings certainly need to be addressed, but it seems to me unlikely this would result in over-heating and nothing but steam coming out the exhaust.

Jim

[Baltimore Sailor]

I don't really know if it was steam; it could have just been white exhaust from a too-rich mixture. But if I did lose the seal on the system and air got in, I'd think it could keep water from circulating and thus overheating the engine.

[SEMIJim]

But if I did lose the seal on the system and air got in, I'd think it could keep water from circulating and thus overheating the engine.

Others may know this better than I, but I suspect "losing seal" is not an issue with these engines and their pumps.

I say this because last fall, when we hauled our boat for the winter, I 1st flushed the warmed-up system with 4 gal. of purple RV antifreeze, then opened all three of the block drains (which the PO had been kind enough to replace with little valves) and let drain from the block what would. Come spring-time, for a test: Got a bucket of water ready, closed those little valves, started-up the engine, dropped my extension hose in a 5-gallon bucket and she started drawing right off. Then shut her down. Next weekend the boat was splashed. Turned the raw water seacock off, started the engine, turned the raw water seacock on, she started drawing right off.

Jim

[Baltimore Sailor]

Today (Sunday) I went over to the boat to run Don's cooling system fault tree. I ran a piece of 1/2" hose from the output side of the water jacket T-fitting into a 5-gal bucket and fired it up. Only got about 1 1/2 gallons in 1 minute at 1000 rpm. I replaced the new impeller with the old one and got over twice as much water under the same conditions.

It's the oddest thing: Don said as much that the new impeller might not work as well as the old one (the "new impeller in an old pump" syndrome), but it's hard to believe when you see it. As far as I can see, the only difference between the old vs. new impellers is that the height of the fins on the old impeller are somewhere between 1/32" and 1 mm taller than those on the new impeller. When I replaced the old impeller it was apparent that the old blades extended just a tad beyond the opening so that tightening down the cover actually compressed the blades slightly. The new impeller did not extend beyond the opening and were not compressed at all by the cover.

I sure don't see how that could make such an obvious difference, but there's no mistaking the difference between 2X as much water being pumped.

Happily, the old impeller is in great shape: very flexible, and just a bit of "memory" in the bend of the fins. I feel secure about getting the rest of the season out of it, and then figure out what to do for next year. I guess I could try soaking it in MMO as Don recommended, but it's hard to understand how that could improve its output by 2X.

It'd be a drag to have to replace the entire pump just because the new impellers don't behave properly in the old pumps.

[Administrator]

Any idea how old the "old" impeller may have been?

Bill

[Baltimore Sailor]

No. The PO hadn't done anything for the boat at all, and he had no idea at all about any maintenance done before he bought her.