Water has gotten into crankcase and Oil
 

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?

What WATER PUMP do you have?

I have the Oberdorfer pump.

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

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/foru...read.php?t=274

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.

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 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?

http://nvision.s463.sureserver.com/public/steam.jpg

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.

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.

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

http://nvision.s463.sureserver.com/public/inside.jpg

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.

Don doesn't think it's his. \

You removed the shoe from the interior?

Bill

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.

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

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.

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.

Be prepared to do multiple pressure tests:

1. Test the entire system, block, pump and manifold all included. If it holds air, the exhaust as the water source is indicated.
2. If the first test leaks air, test the system with the water pump disconnected. No leak, the water pump is the problem.
3. Still leaking air? Test the manifold by itself, inlet and outlet ports on the top. No air leak points to the block as the problem.

A full complement of tests should pinpoint the water incursion source in maybe an hour.

Ok Neil, thanks. I appreciate the additional detail.

FOUND IT (Well, you actually did)
 

Decided to re-read the whole thread from the beginning and realized in your POST #4 you'd actually linked to Don's post that I was referring to. :D

That same post also give good instructions for doing a "quick" cooling jacket test as well as pressure testing the block.

10-4. Yes, that's what I was using as my reference for the test.

Update this evening...

Water pumps and water in oil
 

I need to make a small correction to the record. While MMI and Oberdorfer flexible impeller pumps to not have the same potential for leaking water into the crankcase as Sherwood and Jabsco pumps do, due to their larger weep holes, we do have several documented cases where a leaky seal in both an MMI and an Oberdorfer pump did result in a small amount of water getting into the crankcase. Water is apparently able to cling to the rotating shaft of the pump and work its way past the oil seal in the flange end of the pump. The key here is the amount of water getting into the oil. If there is only a very small amount of water getting into the oil, the water pump should be considered suspect (even MMI and Oberdorfer pumps) in cases where no leak shows up in a pressure test of the water jackets. Don

Did the water jacket pressure test. Put 15lbs on the system and 1 hour later still had 10lbs. That was comforting.

Then did the 3 oil changes. Ran the engine for one minute after each refill. Had the raw water inlet turned off till engine was running and then opened it for the last 30-seconds of that one minute just so some water would flow in.

After each change, the apparent water was disappearing from the oil. That was encouraging. After the third change, I started the engine, opened the raw water valve and let it run for 5-minutes.

I shut it off and went to check the oil. LOTS of water. About a quart if I use the marks on the dipstick. The level was about the same distance above "Full" as "Low" is below the Full mark.

So, what can that mean? The only other thing I did in all of this was pull my impeller. It's on a shaft. I pulled it out, removed the C-clip, changed the impeller and reinserted the shaft like I've done the past 9 years. It interfered once so I turned it and then it seated. I put the cover and gasket back on.

Could I have pushed some seal out when I reinserted the impeller shaft?

Rob, does your pump have a hole in the bottom of the casting?

I don't know. I need to pull it tomorrow. Here Is a photo.. Can you tell what pump it is from this?

That is an Oberdorfer N202M-3 or M-7 depending on the internal cam shoe. It has the drain hole I pictured so I'm having a difficult time wrapping my head around the pump as the source of the crankcase water, especially the volume you report. Water that makes it past the pump cavity seal dribbles out of that hole before it gets to the second seal at the mounting flange end. That's why the hole is there. Some water can make it through if both seals have failed but the bulk of it should be dribbling out. If the pump cavity seal failed you would expect a failed pressure test too.

If that reasoning is correct and we accept the pressure test as accurate, we are left with water coming from the exhaust. And yet, I'm not completely convinced of that either.

Agree with Neil and I didn't mean to send us down the wrong rabbit hole with addressing the pump.
I think it's too much water.

Going with Neil's exhaust thought... can we look closer at the "steam" on the exhaust?
Maybe disconnect the exhaust and run the engine to see if water is still getting in?
It would eliminate or point to the exhaust.