Should you have to flush engine with when you replace lower end due to grease in oil?

rdhj

Petty Officer 2nd Class
Joined
Sep 29, 2015
Messages
102
I had a new lower end put on my 6 hp..i later found milky oil...after showing it to the boat mechanic, they said it was not water but probably grease that they stick on something in the engine when they did then lower end. also the lower end gasket was leaking water to the outside of the motor....so they took it apart and replace the gasket. I just used it two mornings and now the oil is milky again..They said they ran it for 15 minutes and everything looked good...i wondering if they applied new grease to that part again and now it contaminated the oil again. do you think i should change the oil again and see if it happens again or is something wrong...also, is it possible to get gas in the oil and would that also make it look milky?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,048
What motor ?---------What do you mean by a " new lower end put on " on this motor.-------Lower units are pressure tested to find leaks.-------A NEW lower unit would have a warranty I assume.
 

rdhj

Petty Officer 2nd Class
Joined
Sep 29, 2015
Messages
102
it is the 6 hp without the integrated tank..1997 model...the pervious owner stripped out the gears when they hit something, so I got an entire new lower unit
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,048
??----No grease gets into a " new " lower unit.----No water gets into a " new " lower unit.---Part # of the gasket is ?-----After running let the motor sit for a few days before checking for the " milky look " in the gear oil.
 

rdhj

Petty Officer 2nd Class
Joined
Sep 29, 2015
Messages
102
??----No grease gets into a " new " lower unit.----No water gets into a " new " lower unit.---Part # of the gasket is ?-----After running let the motor sit for a few days before checking for the " milky look " in the gear oil.

they replace the driveshaft housing gasket #27-803508016...i did not check the lower oil the oil in question is the engine oil..i look in the dip stick hole and it is a very light tannish brown
 

rdhj

Petty Officer 2nd Class
Joined
Sep 29, 2015
Messages
102
they replace the driveshaft housing gasket #27-803508016...i did not check the lower oil the oil in question is the engine oil..i look in the dip stick hole and it is a very light tannish brown

why would you have to let it sit for a few days before looking at the oil?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,048
Sorry, ---When I read post # 1 It does not clearly indicate that you have a 4 stroke and that the issue is with the motor oil !!!!---Good luck getting the shop to help you here.
 

fhhuber

Lieutenant
Joined
Jun 19, 2014
Messages
1,365
Milky color in engine oil EVER is water getting in the oil.

Blown head gasket most likely.

And if you wait a few days, the oil/water may separate and you can drain water from the engine oil drain. Its not fixed... its just hidden.
 

rdhj

Petty Officer 2nd Class
Joined
Sep 29, 2015
Messages
102
Milky color in engine oil EVER is water getting in the oil.

Blown head gasket most likely.

And if you wait a few days, the oil/water may separate and you can drain water from the engine oil drain. Its not fixed... its just hidden.

Is your first sentence supposed to be saying that water wouldn't get in the engine oil, i.e. is the word EVER supposed to be NEVER....what would a blown head gasket allow to mix with the oil? gas? There is no separation of the milky fluid that I took out of it...does anyone have a good web site or video that shows you how to replace the head gasket?

also, the mechanic did a compression check of the motor when they installed the lower and said it was good, so i'm guessing the piston rings are good
 
Last edited:

fhhuber

Lieutenant
Joined
Jun 19, 2014
Messages
1,365
supposed to say it means you got water in there. That slightly foamy, light brown stuff is emulsified water-oil with some air whipped in. (can almost turn white) Darker just has less air. Almost like whipped cream with a bit of brown food color, as you whip the air in it gets lighter color.

SOMEHOW... water got in.

You have to find it and fix it or you'll trash the engine.

Put a sample of the fluid in the oven at 180 F for about 4 hours. If it turns into normal looking oil, possibly with some water beads (but most should evaporate) I am proven right. Heat will help it separate.

Left long enough even at almost freezing, oil and water will separate. But it can take days or weeks.

US Navy lube oil purifiers use heat and centrifugal force to drive water out of the oil.
http://weh.maritime.edu/campus/tsps/manual/purifier.html
 
Last edited:

rdhj

Petty Officer 2nd Class
Joined
Sep 29, 2015
Messages
102
supposed to say it means you got water in there. That slightly foamy, light brown stuff is emulsified water-oil with some air whipped in. (can almost turn white) Darker just has less air. Almost like whipped cream with a bit of brown food color, as you whip the air in it gets lighter color.

SOMEHOW... water got in.

You have to find it and fix it or you'll trash the engine.

Put a sample of the fluid in the oven at 180 F for about 4 hours. If it turns into normal looking oil, possibly with some water beads (but most should evaporate) I am proven right. Heat will help it separate.

Left long enough even at almost freezing, oil and water will separate. But it can take days or weeks.

US Navy lube oil purifiers use heat and centrifugal force to drive water out of the oil.
http://weh.maritime.edu/campus/tsps/manual/purifier.html

what would be the likely causes of the water getting in be?
 

fhhuber

Lieutenant
Joined
Jun 19, 2014
Messages
1,365
There are few ways for water to get in the oil:

Failed gasket/seal.

A hole or crack in the block or head.

Condensation is a possibility but that would mean a long storage in a high humidity place with poor ventilation and many temperature changes. Rarely enough to have significant water in the oil and one oil change eliminates it.

The oil will smell like gasoline if there's any significant amount of gas in it.

A head gasket leak can get water and gasoline into the oil.

Some gas can get in the oil by getting past the rings... but you wouldn't ever pass a compression test if you're getting significant gasoline in the oil that way.

Gas shouldn't get in seeping by the valve stems because the intake side will be lower pressure than the crankcase and the exhaust side will send (small amounts of) exhaust products into the oil, not significant unburned gasoline.

We expect a LITTLE exhaust getting into the crankcase. blowing past the rings and valve stems. That's a major reason the oil turns black and why you need an oil filter.

These apply to any water cooled 4-stroke.

any sign of water in the oil... find the cause or you will ruin the engine.
 

rdhj

Petty Officer 2nd Class
Joined
Sep 29, 2015
Messages
102
do you know of any websites that go through the procedure of replacing the head gasket? looking a the engine, it doesn't cooer that i can just remove the head as it attached to the a part on the bottom and the bolts for that are not accessible without removing the engine from the lower unit.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,454
TCondensation is a possibility but that would mean a long storage in a high humidity place with poor ventilation and many temperature changes. Rarely enough to have significant water in the oil and one oil change eliminates it.
I got a ton of water into my oil this year on my 90HP Mercury due to a stuck thermostat....condensation because the motor wasn't warming up.
 

rdhj

Petty Officer 2nd Class
Joined
Sep 29, 2015
Messages
102
No Title

just pulled the thermostat and found this and it does not move...hoping this is what is getting other fluids into my oil
 

Attachments

  • photo234788.JPG
    photo234788.JPG
    87.3 KB · Views: 0

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,657
That could be the problem.

Replace it and change the oil, see what happens.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,454
Looks like mine! Glad you didn't get swayed by the blown head gasket theory.
http://forums.iboats.com/forum/engin...hp-four-stroke

20151108_150008.jpg
 
Last edited:

rdhj

Petty Officer 2nd Class
Joined
Sep 29, 2015
Messages
102
when i put on the new gasket on, should I use gasket sealer on it also?

also, does anyone have the manual for the 2007 model that can give me the torque specs for the two bolts for the thermostat cover
 
Last edited:

rdhj

Petty Officer 2nd Class
Joined
Sep 29, 2015
Messages
102
well, i replaced the thermostat and I am still getting contaminated oil after only 10 mins of it addling...the mechanic is telling me it could be the grease from the shaft when they replaced the lower unit. anyone ever see grease contaminated oil before and can tell me what it looks like?
 

GA_Boater

Honorary Moderator Emeritus
Joined
May 24, 2011
Messages
49,038
You need a new mechanic. Actually you need a real mechanic.

Condensation is a slowly building issue, not in 10 minutes.

Do a comp[ression test for starters,.
 
Top