Water in the oil

Jul 31, 2018
13
Hunter Legend 40.5 Presque Isle, MI
2 hour sailing in following winds. Then 30 minutes of motoring to a slip. After sitting 4 days, our oil was like brown molasses and up about 4 quarts.
How can water get in there? My mechanic said it probably backed up through the muffler. Any other ideas?
 
Feb 14, 2014
7,400
Hunter 430 Waveland, MS
1) Restricted Exhaust Riser
2) High point vent on sea water pump discharge plugged, allowing siphon.
3) Any other water source connected to Exhaust that could pressurize.
Jim...
 
Feb 14, 2014
7,400
Hunter 430 Waveland, MS
Did you check your engine cooling system for Antifreeze coolant level?
Worst of all cases is engine block leak.
Jim...
 
Feb 14, 2014
7,400
Hunter 430 Waveland, MS
Then the only way is back flow through an Open engine exhaust valve.
This will NOT happen when the engine is running.
Jim...

PS: By the description of the oil, this may have been happening for a while.
 
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Jan 30, 2012
1,123
Nor'Sea 27 "Kiwanda" Portland/ Anacortes
What motor? Do you have an oil cooler? Turbo charger? What type of mixing elbow? Vented loop at seawater discharge hose?
 
Jul 31, 2018
13
Hunter Legend 40.5 Presque Isle, MI
Yes. Found water when cracking exhaust hose at engine. There's no vented loop on the discharge. Disassembled vacuum vent located on the output side of the raw water pump. Nothing obvious.
 

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Nov 6, 2006
9,884
Hunter 34 Mandeville Louisiana
Sea water pump seal? If it leaks, water can get into crankcase ..
Love the double entendre "Volvo Punta"
yeah .. no "N" in that word
 
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Jan 30, 2012
1,123
Nor'Sea 27 "Kiwanda" Portland/ Anacortes
Listen to Kloudie. First thing to rebuild /inspect need it or not.

Charles
 
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Apr 22, 2011
865
Hunter 27 Pecan Grove, Oriental, NC
Not seeing how water could get into the oil sump from the exhaust system. Yes, it is possible that water could back up into the exhaust with following seas and enter the combustion chamber if an exhaust valve happened to be open, but then how does it get from the combustion chamber to the oil sump?
 
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Jan 30, 2012
1,123
Nor'Sea 27 "Kiwanda" Portland/ Anacortes
Spills into the bore and goes right by the inside of the rings into the crankcase via the piston ring lands.

In this case the source is something else — probably the seawater pump shaft seals — because the quantity is so high.
 
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Feb 14, 2014
7,400
Hunter 430 Waveland, MS
My engine is a Volvo Penta MD22L too.;)
By the nice appearance of yours, I suspect < 1000 hours.

Sea water pump seal?
This is real possibility but rare. Water pump...
15102.jpg

Items# 15 and 16 are the stationary seal to the engine.
MD22A had an oil cooler, MD22L does not.
____
My engine hours ≈1100 hrs when I removed my exhaust Riser.. in next post
 
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Feb 14, 2014
7,400
Hunter 430 Waveland, MS
MD22L exhaust system...
15871.jpg

Riser is 29. Part 26 is the water to exhaust part. I found ZERO carbon or build up in my Riser.
My Riser is just below the Static Water Line of my Boat.
Why did I open mine up?
I had Salt water, not Lake Huron Fresh water, in my oil.:yikes: [from a reason not like your case]
_____
So the most likely cause, I am guessing now.

Your High Point vent is not venting.

That, combined with a worn Sea Water pump impeller, will drip into an open exhaust valve on a non-running engine. Especially if your Riser is below your boat's water line.
_____
Your picture of the high point vent, is not a type I am familiar with, but the top plug has corrosion. So if it is a vented plug that vent hole could be plugged. Plus there should be a check valve under that plug.

Jim...
 
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Feb 14, 2014
7,400
Hunter 430 Waveland, MS
This is a picture of my MD22L and my boat's normal static water line.
VP Overview 2.png


My water pump is Painted and yours is NOT.
Hmmmm?
Have your changed your Sea Water pump recently?
Jim...
 
Aug 22, 2017
1,609
Hunter 26.5 West Palm Beach
I know a few tug captains who spin the engine over for a couple of seconds before turning on the fuel solenoid. That way, if they have hydro lock from water getting into a cylinder, the starter will just stall. If fuel was in another cylinder & it fired, then bending a rod would become a real possibility.
 
Jul 31, 2018
13
Hunter Legend 40.5 Presque Isle, MI
I drained out the water from the bottom of the oil pan. Then I removed and inspected the high point vent. The tiny hole was not plugged, but I ordered a rebuild kit anyway. Then I closed my raw water intake thru hull...realizng I should have done that immediately. This morning the oil level had not changed. So some progress. Seems the water was siphoning overnight while the engine was off. Now to ID what's causing it to siphon. It could be that anti vacuum high point valve, but at this point I'm not sure how to verify
 
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