Water in Oil 4.3 Mercruiser - Please Help

rsherrill

Recruit
Joined
Mar 31, 2010
Messages
2
I have recently purchased a boat that seems to have water in the oil. I checked the oil and it was high. I changed the oil and alot of water came out. I let it run for 30-40 mins and it runs fine. The oil level slightly came up when first ran, but didn't continue to come up. Drained the oil again and its milky white. I talked with a mechanic and he said that it should shoot white stuff out of the top of the motor if the block is cracked. Does anyone have any ideas as to what the problem is? If the block is cracked shouldn't the oil/water rise the longer it is running? Any help would be appreciative
 

Bondo

Moderator
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Apr 17, 2002
Messages
70,513
Re: Water in Oil 4.3 Mercruiser - Please Help

the block is cracked shouldn't the oil/water rise the longer it is running?

Ayuh,... Cracked Block is my guess,...
The level Will rise as you run it, especially when Not on the muffs...
 

searay3

Senior Chief Petty Officer
Joined
Apr 7, 2005
Messages
655
Re: Water in Oil 4.3 Mercruiser - Please Help

Doesn't sound good. There are a few things that can cause that. Cracked block, headgasket, etc. What exactly are you working on, boat don't matter. Engine/drive serial number and year. A teardown and inspection is in order here. Water in the oil that quickly will probably be major damage from improper winterization. The engines tend to crack in the lifter valley. Pull the heads and intake manifold and look around. It will be obvious.
 

wpowell323

Petty Officer 3rd Class
Joined
Mar 29, 2009
Messages
75
Re: Water in Oil 4.3 Mercruiser - Please Help

I have had several late model Vortec's that cracked the bottom of the intake. I would pull the intake and inspect it first, you may get lucky. But more than likely you won't.
 

rsherrill

Recruit
Joined
Mar 31, 2010
Messages
2
Re: Water in Oil 4.3 Mercruiser - Please Help

I ran the boat the other day for 30-40 mins and the oil didn't rise. Would that mean that the block would still be cracked even if it doesn't rise?
 

Bondo

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Joined
Apr 17, 2002
Messages
70,513
Re: Water in Oil 4.3 Mercruiser - Please Help

I ran the boat the other day for 30-40 mins and the oil didn't rise. Would that mean that the block would still be cracked even if it doesn't rise?

Ayuh,... Anything is Possible,...

An Hour on the muffs means Nothing, til you launch,+ Run it...
 
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