Water has gotten into crankcase and Oil

[RobH2]

I'm in shock. I've had a flawlessly perfoming A4 since 2010 when I bought my boat. I change the oil every 50 hours and take good care of it. It's always run well. We set some sort of thread record here in 2010 with an "Overheating" thread when I first got the boat but since that was solved, no issues.

Last week I changed the oil for the spring. I started the engine and let it warm up to facilitate that. I then changed the oil. It came out black and looked like normal used oil.

Two days ago, I changed the impeller and today I changed the spark plugs. The old ones looked pretty good coming out. One had some soot on one side that almost perfectly split the little bent tab that sits over the electrode. But, they didn't look odd or fouled.

So after changing the plugs I started the engine and it started right up on the 1st revolution and idled perfectly. I had good waterflow coming out.

I then thought I'd go for a spin and shut the engine off to just peek inside the distrubutor cap to see how it looked, first ride of the season and all. Looked great.

Then I checked the oil level as I always do before heading out.

It was milky. I'm shocked.

Sorry for rambling. So, I don't know know where to start to try to figure out how water could have gotten into the crankcase apparently so instantaneously. Failed head gasket? Any good advice on how to start diagnosing?

[roadnsky]

What WATER PUMP do you have?

[RobH2]

I have the Oberdorfer pump.

Edit:You know, I may have an MMI Flange Pump, hmmmm. Regardless, what are you thinking?

[RobH2]

I searched pretty well before I posted and couldn't find any threads using "water in oil", "water oil", etc., but a Google search did find a good thread.

So, I'll use this for now and do the diagnostics Don recommends.

http://www.moyermarineforum.com/forums/showthread.php?t=274

[ndutton]

The first thing I would do is a cooling system pressure test. This will determine if the water jacket is intact (let's hope it is). If the pressure test fails, test the manifold and block separately. These tests will narrow down the source of the water to reduce the guessing.

[ubxf]

i'm just a newbie studying all i can about this engine but i found out recently that a small hole in the head right under the thermostat can cause the trouble you are describing.

[RobH2]

The first thing I would do is a cooling system pressure test. This will determine ...... to reduce the guessing.

Thank you Neil, that's where I'll start. No use wasting gallons of oil with 3 changes until I see the result of a pressure test. From what I've read so far, it's pretty easy to do.

I did notice one other thing that might be an indicator of a problem. I have a water lift exhaust (I think that's the right word for it) that is stainless steel. A black iron pipe exits the manifold, "U's" up and turns to come down into it. It's wrapped with a cloth heat wrap. I noticed it steaming a lot yesterday.

That might indicate a leak in the pipe, but for a pipe that thick to leak, it probably means that it's likely very rusted out internally. It's 9 years old and has 350 hours on it.

Question: If it's really rusted out inside, could it block waterflow, cause backflow and force water into the crankcase?

[RobH2]

i'm just a newbie studying all i can about this engine but i found out recently that a small hole in the head right under the thermostat can cause the trouble you are describing.

Thank @ubxf, I'll definitely check that. I'll take any diagnostic advice I can get and this is worth both checking and knowing about for future observation.

[ndutton]

Question: If it's really rusted out inside, could it block waterflow, cause backflow and force water into the crankcase?

Of course you'll want to chase the source of the steam down and repair whatever needs repairing but looking at the design of the hot section and the area you report the steam is coming from I'm doubtful it is the cause of your water incursion. As for the exhaust water being blocked, in your first post you reported good water flow out the exhaust so I'm doubting the blockage guess too.

None of this is conclusive, just grasping at clouds at this point. Let's see where the testing leads.

[RobH2]

The thumbscrews on the cover of the water pump suggest that it's an MMI product.

Bill

HI Bill, is this photo enough for you to tell what water pump it is?

[RobH2]

Of course you'll want to chase the source of the steam down and repair whatever needs repairing but looking at the design of the hot section and the area you report the steam is coming from I'm doubtful it is the cause of your water incursion. As for the exhaust water being blocked, in your first post you reported good water flow out the exhaust so I'm doubting the blockage guess too.

None of this is conclusive, just grasping at clouds at this point. Let's see where the testing leads.

Yes, I had good exit water flow but I did seem to have a feeling is was maybe slightly diminished but brushed it off. If diminished compared to normal, it wouldn't have been more than 10%. Of course, this is all just visual. I didn't measure gallons per minute or anything. Point being, the exhaust is not blocked, water was moving through nicely.

I just need to get down there and do the pressure test.

[Administrator]

HI Bill, is this photo enough for you to tell what water pump it is?

Don doesn't think it's his.

See the 1/4" pipe-threaded
hole for a drain plug in the bottom of the impeller chamber? We don't have
that drain plug.

\

You removed the shoe from the interior?

Bill

[RobH2]

I'll get a better photo. I was just grabbing what I had. I had pulled the pump and completely disassembled it, so yes, the shoe is out. I had taken that photo for a completely different reason 9-years ago when I was having the overheating issues. Jerry had asked what pump I had but he didn't specify why that might lead to water incursion.

[roadnsky]

Jerry had asked what pump I had but he didn't specify why that might lead to water incursion.

Oops! So sorry... Didn't mean to leave you hanging. Got buried at work and just re-surfaced.

I asked which pump you had because I remember reading that a Jabsco pump MAY possibly pass water past the shaft seal into the crankcase.
Less likely than other causes that you've been pointed to.

I'll look and see if I can find that posted info ( I believe by Don)
The pressure test that Neil suggested is definitely the place to start tho.

[RobH2]

No problem Jerry. I'm heading out now to get some fittings so I can do the pressure test today. I'll report back in later tonight.