Charleston NC or further south, mechanic

[Sony2000]

My friends are heading south, needing a mechanic to check out the cam in the raw water pump for wear, or and the thermostat. They have a slight loss of coolant, and the first stop should be Charleston NC in two days, then further south, over the next few weeks.

[Al Schober]

Hey Sony,
Kinda curious what symptoms your 'friends' are seeing to make them wonder about the water pump cam and the thermostat. BTW, neither of these are related to a coolant leak.
First the coolant leak - I'm guessing an engine with a heat exchanger (otherwise why would they worry about a little leak). I went through the same thing when I went to glycol coolant - pesky leaks from the water pump. After numerous 'fixes' (that didn't work) went to the new Moyer pump. End of problem. But they should at least be able to determine that it's the water pump that's leaking.
As to the other two items, perhaps they're running hot - perhaps due to low coolant circulation. If they're raw water cooled, then just check the flow over the side. Worn cam? It would be the first one I've ever seen. Much more common to have the impeller shed a blade - which goes downstream until it lodges & blocks flow. Thermostat? Maybe - test is take it out and run without it. Then you can also put it in a pot on the stove with a thermometer and see when it opens (if at all).
Charleston, NC? The only one I know is in SC - but that doesn't mean much. It's gotta be warmer there than it is here! If they really need a mechanic, I'm ready for some warmer weather & would entertain an offer.

[Sony2000]

My mistake, it's always been SC. After a lot of hard running against the currents, the Yanmar 4 leaks from atop of the engine, and it has had a small overheating problem. The prop was repitched in Beaufort NC. The raw water impeller is new. Communications are not the best, and all the bugs are not out of their new (to them) boat. My two cents is to change the cam (shoe) and improve the volume of water. However a good mechanic in SC is welcomed knowledge, before the pricier ones of Florida, and their departure for the BVIs.

[Mo]

ponderings

Few possible causes

- heat exchanger leak: a pinhole in the heat exchanger would cause a drop in antifreeze / coolant level.
- loose hose clamp somewhere in the system causing small leak.
- pump leak as mentioned
- head gasket leak...if small the engine may run perfect until fluid loss is such that it looses cooling capacity.
- not sure about the manifold on a yanmar but if it has a hot and wet side a pinhole there may do it as well.

Note when dealing with diesels....they do NOT like to overheat. It is a very rare case that a diesel overheats and doesn't need the head removed for a head gasket job at the very least. The head can warp on these as well...it would be very beneficial to know if the engine overheated.

Hope that helps out.

[ndutton]

Is it leaking salt water or coolant? As for overheating, my limited experience with Yanmars is salt encrustation inside the heat exchanger and mixing elbow. I don't know why but I've never seen another engine salt up like a Yanmar.

[Administrator]

Overheating problem before/after repitching the prop, or both?

Bill

[Sony2000]

They are wanting to leave Georgetown SC and do another leg prior to the next weather system putting them back into a port. Getting into the harbour caused a "pooling of coolant on top of the saildrive below a hose". I'm awaiting a further investigation.

Overheating prior to repitching. I asked if there is a pressure relief valve in the cap, on the coolant reservoir.

Salt encrustations sounds good. The PO had arrived from Brazil.

[ndutton]

"pooling of coolant on top of the saildrive below a hose" seems pretty incriminating to me.

Step 1: replace that hose.
Step 2: replace the rest of the hoses. They're all the same age and have been subjected to the same conditions.

[Al Schober]

OK folks, recoil, back to battery, secure.
This poor guy wasn't looking for repair advise, just a mechanic. He doesn't even have an Atomic 4! It's posted under 'Good Guys', not 'Help!' All he's looking for is a competant mechanic.
Blame me - I started out assuming he had an Atomic 4 and offered repair advise - my bad!