Water in Oil

jforrest1

Seaman
Joined
Sep 29, 2014
Messages
63
I have twin 2002 Volvo 5.0 GXI engines in my 31' Larson. They have less than 500 hours and due to various circumstances (not with the boat) I put on less than 15 hours this year. Last Saturday, I was changing the oil in preparation for the marina winterizing and storing the boat for the winter and found water in the oil in the starboard engine. The engine runs great, always within temp and oil pressure. No leaks that I can see in the bilge or around the engine but in all honesty I didn't due a full well lit search with the engine running. I continued on and changed the oil and filter in both engines.

I spoke with a person who owns a shop and had winterized my previous boats. He said 99% this is a result from a faulty winterization and the block is most likely cracked. If it was a head gasket the boat would be running rough. He admitted there is a small chance that a manifold gasket might be the cause. He said in his experience most likely the block. He said this is his fear and his name is on the work he does so he would make it right and has done so in the past. There is always a couple of boats he worries about all winter but takes extreme care in doing the winterization just for this reason.

My marina is a small family marina on a lake and the mechanic has taken a few days off to attend the fairs. It is fair season in Maine! I have spoken with them, called and emailed to contact me as soon as possible when he returns so we can discuss. As of today (Thursday) I have not heard from them. So I guess I wonder about:

1. If block is cracked would it run fine and show no apparent systems...other than the oil?
2. If block is crack, is it fair to say it is from a faulty winterization? Are they other causes?
3. Is that a common practice to stand by your work and take responsibility?

Thanks - Jim
 

ahicks

Captain
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Sep 16, 2013
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3,957
How much water are we talking about? If the engines were started a few times during the season, and not allowed to come up to temp long enough to burn off the normal condensation, some times they'll form even more condensation that can accumulate easily!

I've seen them run with no apparent symptoms.
If the boat is kept in salt water, corrosion could be the cause.
Only the best will back their work 100%. Many others will, but you have to get their back against a wall. Others will require unrealistic proof and/or legal action.
 

bruceb58

Supreme Mariner
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Mar 5, 2006
Messages
30,454
Pressure test the block to see if its a cracked block.

If it's a small amount of water causing the oil to get milky, it could be a bad manifold or manifold/riser connection.
 

rallyart

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Jun 7, 2008
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1,175
A cracked or broken block can still run very well. The statements by your mechanic are particularly honorable as he is accepting responsibility based on his best guess and not trying to duck even though he has not definitely found the problem. A good man.
ahicks comments on condensation are worth considering. Normally the oil will mist off any condensation at operating temperature but if it looked milky when you changed it, it is more likely water from the block.
 

jforrest1

Seaman
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Sep 29, 2014
Messages
63
Pressure testing the block is probably going to be first in line. Still waiting to hear from the mechanic at the marina. Unfortunately those statements are from my old mechanic and not the marina mechanic. I can't haul the boat to him and he was not willing to travel and do the winterization for me as he has his own business and is very busy. He is a good man. The color of the oil was like a regular coffee - tan.
 

tpenfield

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Jul 18, 2011
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Did this shop do the prior winterizations? Sort of assume so, but you did not exactly state if they did so on this boat vs. your previous boats.

Pressure testing the engine block would be good.

However, I like to do the easier stuff first. So, I'd go for looking at the exhaust manifolds to see if there is water in the exhaust passage.

I'd also remove the spark plugs to see if there is water in any of the cylinders.

Then take it from there. If it is a cracked block and the shop takes responsibility, then you will be getting a 'new' engine (long block)

As to your questions:

1. If block is cracked would it run fine and show no apparent systems...other than the oil?
Yes . . . until it decides to have a catastrophic failure (Ka-Boom :eek: )

2. If block is crack, is it fair to say it is from a faulty winterization? Are they other causes?
Winterization fail . . . not really any other causes

3. Is that a common practice to stand by your work and take responsibility?
No . . . more typical is to point fingers and run away.

Let us know how things go.
 
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wengr

Cadet
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Aug 9, 2017
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18
I have zero experience with marine head gaskets. But I wonder how one can rule out a head gasket so easily. Is it not possible for it to breach between water jacket and oil, yet still seal to combustion chamber? Happens often in automotive applications, and the engine runs fine, until you notice the milky oil, or worse yet you don't notice the milky oil.
 

tpenfield

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Marine head gasket is only different in material. I would think it cannot be ruled out or ruled in.

We do see some folks tear into their engine believing that the head gasket is bad, only to find that it is in good condition.
 
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Old Ironmaker

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Dec 28, 2015
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3,050
Could lack of cooling because of a bad water pump/impellor cause a cracked head or head gasket?
 

Lowlysubaruguy

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Dec 3, 2012
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514
Theres also a chance the intake gaskets failed they degrade and leak into the oil. I see many cars with water in the oil thats a failed head gasket or cracked block that run great and don't overheat until there low on coolant and you wont run low on coolant in a raw water coolant system.
 

Lowlysubaruguy

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Dec 3, 2012
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Old iron maker loss of coolant flow and an overheat condition can crack heads and blocks usually in the weakest points heads like to crack from this between the valve seats where the casting is the thinnest blocks between cylinders. Most blocks that are cracked in other places are usually from freezing
 

Trevor H

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Oct 9, 2017
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5
Hi Jim,

This might help:
1. If the block is cracked you should see a drop in oil pressure as well as water in the oil

2. faulty winterisation can cause problems when coolant is re-added to an engine if it is not mixed properly gaskets can be blown, the most common cause of a cracked block would be overheating, due to blocked coolant water intake, seacock not turned on, or running with insufficient oil

3. it is very unusual for an engineer to suggest it might be something he did
 

bruceb58

Supreme Mariner
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Mar 5, 2006
Messages
30,454
Hi Jim,

1. If the block is cracked you should see a drop in oil pressure as well as water in the oil[/COLOR]
Not if the crack occurs where there is no oil pressure which is 99% of the area within the block where the water jacket is adjacent to an oil passage.
 

jforrest1

Seaman
Joined
Sep 29, 2014
Messages
63
So spoke with the mechanic who winterized the boat and he is confident in his work and the extra caution (not sure what that is but didn't expect him to say anything different) he takes in doing the winterization. I'm waiting to hear back from him about taking the boat out of the water and doing the compression test as well as checking the plugs for signs of moisture. After I changed the oil, I started it and the next day went to the pump out dock. I went down last week to pack it up for the winter and the oil looked great as if just out of the quart. I told him that and when I did my year wrapped up, I only put on 10 hours! Much of that was slow cruising out to the island. One of the possibilities he said, which is what ahicks mentioned earlier about just condensation. If test holds and no sign of water in plugs or oil he'll put it up for the winter and we'll keep an eye on it next summer. If water comes back, we'll start looking at other things including gaskets.
 

shrew

Lieutenant
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Dec 29, 2006
Messages
1,309
When is the last time the manifolds, risers and elbows were replaced? I'd be more apt to suspect those or a blown head gasket over improper winterization. Especially if the winterization was done by a marine professional.
 

oldrem

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Nov 7, 2013
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Had brown milky oil issue with my Mercruiser 188 I/O in old Carver years ago. New manifolds and risers were all she needed.
 
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