Milky motor oil

Casagf66

Casagf66

.
Nov 12, 2014
90
Jeanneau 42 Northport
Hello gang,

I just purchased a 1989 jeanneau 41 voyage with a perkins m50 desiel. I went to winterrise the motor the other day and discovered the impeller was torn to shreds, the motor coolant was low and the motor oil was milky. The oil looks like coffee with creamer in it. After doing some research I guess this may be because a failing head gasket?


When running the motor, she sounds fine and revs up nicely. There is not a lot of smoke coming out the back after she's warm, but she is on land so I've only ran here for about 20 minutes at a time. I also hear some rattling coming from the bell housing. Tranny works in foward neutral and reverse. Haven't had a problem with overheating yet.

I've tried contacting the owner, but have had no luck, the broker I purchased the boat is also clueless why this is.

I guess my question is what should I do. I was thinking about changing the oil a few more times maybe it will go away and was just a fluck?
 
Last edited:
njlarry

njlarry

.
Sep 23, 2009
1,475
O'Day 34-At Last Rock Hall, Md
Change the oil NOW as it has water in it that will damage your crankshaft and bearings. Others more knowledgeable will help you with the diagnosis and treatment.
 
Casagf66

Casagf66

.
Nov 12, 2014
90
Jeanneau 42 Northport
10 - 4 thank you . I changed the impeller and oil last night. I plan on changing the oil again this weekend.
 
Last edited:
thinwater

thinwater

.
Mar 26, 2011
3,670
Corsair F-24 MK I Deale, MD
You can have the oil tested for glycol and water. Is there oil in the coolant, or has the coolant level dropped?
 
Casagf66

Casagf66

.
Nov 12, 2014
90
Jeanneau 42 Northport
That's a good idea.

There is no oil in the coolant, but I will investigate closer this weekend.

I topped off the coolant yesterday after I changed the oil.

When I purchased the boat the coolant was low.
 
Head Sail

Head Sail

.
Nov 13, 2013
723
Catalina 34 Tacoma
Blown head gasket or cracked block is the likely cause. Unless someone put coolant in the oil fill hole.
 
M

markwbird

.
Nov 26, 2012
1,654
C&C 40-2 Berkeley
Sometime it takes several oil changes to get all of the water out. Be sure to change the filter as well. You could run a compression check to see if you have a head gasket problem. Check mixing elbow to make sure it is clear of soot. Clean the engine to make leaks easier to spot. A power washer works well for this if you don't mind a little water in the cabin. If it is a head gasket it may not be the end of the world. Just change the head gasket.
 
Casagf66

Casagf66

.
Nov 12, 2014
90
Jeanneau 42 Northport
I plan on changing the filter and oil twice this weekend. Im thinking about using a quart of desiel fuel mixed with the motor on the first change. On the second oil change I'm thinking about using a quart of Marvel mystery oiI mixed in.

I would like to test the compression, that's a good idea... does anyone have recommendations for a compression testing kit?
 
Last edited:
J

jimg

.
Jun 5, 2004
175
catalina 27 dana point
Just change the oil and filter. No magic additives or diesel fuel. You are trying to get the water-tainted oil out, nothing more. As mentioned above, it may very well be a head gasket or worse. I hope you have a positive outcome with the oil change, though.
 
Charles Erwin

Charles Erwin

.
Jan 30, 2012
1,139
Nor'Sea 27 "Kiwanda" Portland/ Anacortes
The various diagnosis - head gasket, fractured head, and so forth - may be premature.

You need to verify that the sea water pump is not leaking raw water through its shaft seals (there are at least two.) The shaft also needs to be checked for wear. If these are worn raw water goes directly in to the crankcase.

Charles
 
Casagf66

Casagf66

.
Nov 12, 2014
90
Jeanneau 42 Northport
Charels,

Its funny you say that, I did notice when changing the impeller that there is a open slot where you can see the raw water pump shaft. After looking at it closer it was smooth and shinny, but there was an O ring on it that was floating around....

Do you recommend I replace the shaf seals?

I am not formula with Perkins m50 motors, but I need to learn. This would be a good time.
 
uncledom

uncledom

.
Jun 11, 2011
1,243
Hunter 41 Lewes
How have you been feeding water to the raw water pump while she's been on land? If you have been using a garden hose to feed it you may have caused blow by due to the amount of pressure the garden hose can generate. Just a thought.
 
  • Like
Likes: mytime
Charles Erwin

Charles Erwin

.
Jan 30, 2012
1,139
Nor'Sea 27 "Kiwanda" Portland/ Anacortes
By all means - it won't hurt and if it is leaking the shaft bearings are toast too.

Charles
 
Head Sail

Head Sail

.
Nov 13, 2013
723
Catalina 34 Tacoma
Another possibility...What type of muffler do you have? I have an aqua lift muffler. If you crank the engine without it starting for longer than 30 seconds, you are supposed to drain the aqua lift. Otherwise raw water gets sucked into the engine.
 
Casagf66

Casagf66

.
Nov 12, 2014
90
Jeanneau 42 Northport
Uncle dom,

I think you're onto something. Now that I look back at it, I was having trouble getting water to my impeller in the beginning and it was driving me mad. This was before the milky oil was noticed.

I had a hose clamped to the raw water filter intack and a bucket with a garden hose. Trouble was the bucket was to low, but i didnt realize this right away. Instead I was filling the raw water hose directly with the garden hose and blowing water into the pump. I thought this would help. .. I eventually lifted the bucket above the motor and the impeller started to pull.

By doing this could I have pushed water in the motor...? where would this water have gone? I'm confused in the matter.
 
Last edited:
A

alexco38

.
Sep 25, 2008
1,096
CS 30 Toronto
That why I put a "T" after the water intake thru hull. You can turn off the water intake, connect a hose to the "T" and dip it in a bucket at the engine level. No water pressure, just suction.

The garden hose with pressure pushes water pass the impeller vane, to the mixer elbow, fill up the muffler and back into the cylinder head and into the engine.
 
JamesG161

JamesG161

SBO Weather and Forecasting Forum Jim & John
Feb 14, 2014
7,744
Hunter 430 Waveland, MS
Casagf66 said:
I guess my question is what should I do. I was thinking about changing the oil a few more times maybe it will go away and was just a fluck?
Click to expand
Did you spell FLUCK right? Extra letter maybe?
This is a good thread on similar problem...
http://forums.sailboatowners.com/index.php?threads/water-in-engine.175063/
You can check the milky oil with swimming pool NaCl test strip. If fresh hose water, no change in strip. If you use a automotive antifreeze, it will show under a UV light in your milky oil.
Find the source of water first!
Jim...
 
M

markwbird

.
Nov 26, 2012
1,654
C&C 40-2 Berkeley
A leaky raw water pump will not get water into the oil. Is this boat on the hard? If so and you are using a garden hose to feed water into the raw water pump then you are very likely to get water into the oil. NEVER run the hose with the engine off. Start the engine and have someone turn on the hose immediately then turn off the hose just before cutting the engine. Back pressure from the running engine is the only thing that keeps the water that gets pumped into the exhaust from going backwards into the engine through the exhaust manifold. I've made this mistake myself and it took five oil changes to get all the water out.
 
You must log in or register to reply here.

Top Bottom