[rlmccb]

Recently I had an impeller come apart. My engine had started to smoke more than usual and the water flow through the exhaust had diminished. While checking the impeller I noticed it had several vanes torn off and the outflow to engine fitting in the pump was plugged with debris. After changing the impeller I fired up the engine and although some water was coming out with the exhaust not the amount I was used to seeing. I looked at the water pump and it appeared to blow out a seal allowing a large amount of water to escape through the seal. I changed the seal, same deal. I am assuming that when the impeller came apart that some debris must have lodged itself down stream creating the pressure that causes the water in the pump to blow by the seal. Question, what is the operating procedure for clearing debris,,,,,,???? I'm going to start with the line which leaves the pump and goes to the engine, tracing from there whatever I can,,,,,,,any suggestions??
thanks,
Rick

 

[MarkofSeaLife]

Hi Rick,

Its an easy fix.

The impellor fins lodge in the enterance to the oil cooler. Its at the back of the engine and looks like a large black sausage.

You rip the damn thing out and taket it to an auto radiator repair shop where they rip the end off, clear out the rubbery bits and braise the end back on again.

Simple and quite inexpensive!

Mark
PS this is an internet forum so everyone will tell u I am nuts and you need a new engine and should use paper charts!

 

[Minnewaska]

Nothing wrong with Mark's suggestion, assuming he already knows you have that exchanger. They are all a bit different. Some, you can get the end off, without removing the exchanger at all. I do suspect it is clogged and you may need to ream it out, if you do it yourself.

I doubt the water pump leaked past its seal because of the clog. I don't think they create that kind of pressure, especially since the clog wasn't absolute. More likely, it heated up and the tolerances have been distorted. Water pumps are a wear item anyway. I would consider replacing it, but they can be pricey. I've long been cautioned not to bother rebuilding water pumps.

 

[chuck5499]

Mark is correct. Check your oil cooler and you will probably find the parts. We had a similar issue a couple of years ago but still had good water flow so no issue but this year in some routine maintenance we pulled the oil cooler and found the parts for a couple of years ago.

 

[rlmccb]

By the way the engine is a 1974 Palmer P60
thanks for any suggestions,
Rick

 

[tempest]

Looks like there's a pretty active group of Palmer engine owners that swap parts and info.
Someone actually tracked down and documented all the serial numbers/buiild dates etc.
Interested history.

Is your engine Raw water, or fresh water cooled?

 

[rlmccb]

The engine is raw water cooled. This is what I have found thus far. The line which flows from the water pump to the engine block was plugged. After taking it off I could see a couple of fins from the impeller jammed on the outlet end. I took it over to a spicket and ran pressurized water through it or tried to, very, very little could get out. I worked on it for a little while and managed to get it completely cleared. Put it back together and the leakage at the water pump was greatly reduced. I'm going ahead and replacing the seal and we'll see what happens. I also checked for debris at the heat exchanger and found none. Thanks to all for your suggestions, I'll let you know what else I find out.
fair Winds
Rick

 

[Minnewaska]

Little bits caught where you can't see them is your risk. Pay careful attention to engine temps and to water flow. If either appear off, they are. Not sure how to recommend cleaning them out, perhaps there is a solvent.

I've never understood why boats with rubber impellers don't have a strainer after the pump and before the bits are sucked into the passages. Everyone will eat an impeller eventually. I've lost count of how many I have in a lifetime. (and I still haven't installed said strainer )

 

[rlmccb]

The strainer sounds like a great idea, I'll have to give it some thought.
thanks for the suggestion, a way to clean out would be great. I also think that from now on I will subscribe to the philosphy that impellers should be changed each year. It seems that pretty cheap insurance./
fair winds my friend
Rick

 

[Minnewaska]

...I will subscribe to the philosphy that impellers should be changed each year. ...

Absolutely. First thing on every spring commissioning list.