Re-engined boat developed water in oil. Can it be heat exchanger?

[teamspoad]

~~~I REALIZE THE LIKELIHOOD OF A BLOWN HEAD GASKET, OR HEAD ISSUE, BUT....""""~~~

Hi,
I don't know where to begin with my question, so any leads are helpful. I have an older VW pathfinder engine with a bowman heat exchanger. I just installed the engine, got it running without water (just for a very little while to make sure fuel & electric was working) and it ran fine. Once water pump was installed, and engine was run for a minute or so, it wouldn't restart (after idol was set too high, shut off, fixed, restarted 2 times no issue, 3rd time wouldn't start), and I had water in the oil.

I REALIZE THE LIKELIHOOD OF A BLOWN HEAD GASKET, OR HEAD ISSUE, BUT....

I was wondering what possibility it could be leaking from the heat exchanger. For one, there is no antifreeze detected (circulated from internal water pump and antifreeze tank), and it only happened once water was introduced, so it seems possible it could be heat exchanger issue. it is an external water pump, so it can't be leaking from the raw water pump. I'm not experienced in wet exhaust systems so I don't know the possibilities of it leaking from the heat exchanger. I did not have a chance to view the exhaust aft of the transom to know if there was proper water exit. It was never run for over a minute.

Thanks for any help or direction you can provide.

 

[MikeHoncho]

Unless you have a oil cooler, no.

 

[Davidasailor26]

You say there is no antifreeze detected. Do you mean there is no antifreeze in the oil, only water there? Also, I assume you have an engine with a closed water cooling system (antifreeze) and raw water system to cool that, via the heat exchanger?

If the answers to the above are yes, As Mike said, the only way I could imagine raw water getting into the oil would be if you had an oil cooler. In a typical system the raw water goes through the heat exchanger to cool the antifreeze, then into the exhaust. If there were a heat exchanger problem it would allow raw water into your antifreeze, or vice versa, but nowhere near the oil.

Is it possible that your exhaust is somehow partially blocked, or in some other way fouled? The raw water gets pumped into the exhaust elbow, so if there were a problem there it is possible that water could back up into the cylinders. From there it would still need to somehow get down into the oil, but it's about the closest path for raw water to get to oil on a fresh water cooled engine.

 

[kloudie1]

If raw water pump is gear driven, could be a bad pump seal leaking water into crankcase. Not familiar with that engine at all. Otherwise, head gasket or head

 

[Capt jgw]

OP said external water pump. I assume he meant belt driven so that's not the source. Also assuming this is the first time he's run it with water or AF in it. That leaves the head gasket or cracked head or block.

 

[TimFromLI]

How long did you crank the engine when it would not start. Could the raw water pump have pumped water into the exhaust hose and and back-flowed into the exhaust manifold?