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

[Spoooner]

~~~""""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.

[Montanan]

The raw water to antifreeze treated cooling water">engine cooling water heat exchanger could have a leak which would allow for raw water to mix with the antifreeze treated water and dilute the antifreeze treated water. But unless there is a leak in the engine cooling system into the crankcase there should not be cause for water to entrain into the engine oil, yet that is what you are apparently seeing happen. You state that there does not appear to be antifreeze in the oil / water mixture, but I am not sure how you can tell whether the emulsion has antifreeze blended in the adverse mixture. If there isn't antifreeze in the oil then the water being entrained into the oil seemingly must be entrained other than via the engine cooling water system, so perhaps a back filling from the wet exhaust is a possibility.

Some references that may be of value as to discerning wet exhaust system issues.

https://www.sbmar.com/articles/desig...xhaust-system/

https://www.sailmagazine.com/diy/mai...diesel-exhaust

https://www.westmarine.com/WestAdvis...-System-Basics

[DougR]

- could be a head gasket issue, but as you say, no evidence of antifreeze in the oil.....
- unlikely to be a HE issue, because as the engine heats up a leaking HE will frequently put antifreeze into the raw water side
- does the engine have a raw water cooled oil cooler? This can put water into the oil
- most likely cause in my mind is water that backed up the exhaust system and into an open exhaust valve, then worked past the rings and into the oil. This could also have caused the engine to not turn over and not start.....

DougR

[model 10]

You ran the engine with out the salt water pump installed and it ran OK? You install the salt water pump and you have water in the oil? Take the pump off and run it again

[Lepke]

Water can get in the oil from a bad seal if the raw water pump is gear driven. The head gasket could leak. The head or block could have a crack. The oil heat exchanger could leak.
If you cranked for a long period, raw water could have flowed into a cylinder and then forced past the rings when trying to start.
Pressure test the coolant system. If ok, compression test each cylinder. Take the oil heat exchanger to a radiator shop and have it pressure tested.

[deblen]

How did you supply seawater to the seawater pump?

Was the boat in the water?
Was the seawater sucked into the seawater pump by the seawater pump?


If you force water (garden hose,etc)into a seawater pump system,the seawater can "back up" & enter the engine via the exhaust valves.
Len

[osprey877]

I have the same engine. I think Lepke above is probably correct. The only place raw water and oil meet directly is the oil cooler, which is easy to remove and have checked at a radiator shop. If the oil cooler is okay, then it’s probably fresh water/antifreeze in the oil and you’d want to do the pressure and compression test Lepke suggests. Good luck.

[osprey877]

Just read Len’s reply. His scenario is definitely another way raw water and oil could mix in the pan. Over cranking the engine could also have the same result as there is no exhaust pressure to empty the muffler.

[Sailnav]

Check the seal between the engine and the raw-water pump.

[Bill Seal]

Reading comprehenson problem?

it is an external water pump, so it can't be leaking from the raw water pump.

Before giving sage advice, it would be best to read the OP's posts, though he was rather vague about what he meant by "won't start"

[model 10]

If the weep hole between the 2 seals in the water pump is clogged, water can pass into the sump.

[Mikado]

Another way that raw water can get into the crankcase is if the raw water exit hose that attaches to the mixing elbow doesn’t have an anti siphon loop and is below the waterline. Raw water will back flow into the combustion chambers thru the open exhaust valves and leak past the rings into the crankcase oil.

I know this thru personal experience.

Jeff

[MelvilleSmith]

I had this happen and it turned out to be a failed anti-siphon valve in the vented loop through which cooling water passes after exiting the heat exchanger and before entering the exhaust mixing box. When you turn the engine off this valve lets air into the vented loop and breaks the siphon which would otherwise keep raw water flowing into the box and backing up into the engine.

[Spoooner]

I think the anti siphon was bad. I replaced it, but I'm also going to replace the lift Muffler before I try and start it again. I've done one oil change, I'm not real sure about the best way to get rid of all the water, nor am I so confident about starting it up without a different lift Muffler setup , because I was using an old one that I could hear rattling inside. I assumed it was some debris that would get blown out, but now I think I should just play it safe and get a new one.

Centek said everything should be 2.5", but its original was 2 inch hose and 1.88" muffler. Anyone know why 1.88 muffler and 2 inch hose would be a problem, they were very vague and seemed lawsuit leery, they just said it could "cause issues" and that was without mention of water in oil.

[Mikado]

Originally Posted by Spoooner

I think the anti siphon was bad. I replaced it, but I'm also going to replace the lift Muffler before I try and start it again. I've done one oil change, I'm not real sure about the best way to get rid of all the water, nor am I so confident about starting it up without a different lift Muffler setup , because I was using an old one that I could hear rattling inside. I assumed it was some debris that would get blown out, but now I think I should just play it safe and get a new one.

Centek said everything should be 2.5", but its original was 2 inch hose and 1.88" muffler. Anyone know why 1.88 muffler and 2 inch hose would be a problem, they were very vague and seemed lawsuit leery, they just said it could "cause issues" and that was without mention of water in oil.

I seem to recall mention of the engine not starting as well. If by this you mean that along with water in the oil the engine will no longer turn over that probably means that the engine is hydro-locked with water in the cylinders. Be very careful trying to start the engine if this is the case because you can do serious damage like bending connecting rods.

The only way to resolve the issue would be to pull the injectors and turn over the engine which would force the water out thru the injector openings. If you do this, make sure that you put a towel over the openings otherwise watery oil will be everywhere in you engine compartment if you don't !!

Good luck,

Jeff