4.3 mercruiser water in oil

[lowpressure68]

alright, just got back 2 hours ago. got about 200 yards from launchingthe boat and it bogged down and shut off. popped the hatch and there was that greyish colored oil/water mixture all over the top of the motor where it had blown out of the top of the dipstick. got a tow back in and i sucked all the water/oil out of the pan and took out the plugs so i could clean those and make sure there wasnt any water in the cylinders......all clear. put the plugs back in and started it up and it runs fine. so........what is the best way to find out if the water was coming from the exhaust manifold, intake manifold, block, or heads? or is there somewhere else on the boat motors? ive been an automotive mechanic for over 20 years but this is my first boat so im working out the differences. any and all information will be appreciated.

thanks
steve

 

[Bifflefan]

Re: 4.3 mercruiser water in oil

Water gets in the oil in the same places on a boat as a car. No biggy there.

When you say "runs fine". Do you mean that the engine is running good or there is no more water getting into the oil?

did you measure the water/oil that you took out of the pan? Was it mear condensation or was it clear full of water/oil?
The reason it may have sputtered and shut down is water on the cap/wires and so on.

 

[lowpressure68]

Re: 4.3 mercruiser water in oil

i pulled about 5 quarts of water out of the pan with my suction machine. since the pump is in the outdrive and the water runs through the exhaust manifolds i just wanted to make sure there wasnt something different that im missing. it wouldnt run earlier due to the excessive amount of crankcase pressure that was allowing some water to make it past the ring seals and into the chambers causing the plugs to foul. its definitely still leaking water into the pan but i havent found where from yet.

also, this boat has been running without any problems for 2 seasons now so this is the first time ive had to break into the motor.

 

[Bondo]

Re: 4.3 mercruiser water in oil

its definitely still leaking water into the pan but i havent found where from yet.

Ayuh,.... My Guess is, it was Winterized, Poorly,+ the block Froze,+ Cracked...

Drain,+ Isolate the cooling system,+ pressurize with Air, 'bout 15psi will do, you'll Hear the leak...
Then follow the Sound...

 

[lowpressure68]

Re: 4.3 mercruiser water in oil

good enough for me.....i have a cooling system pressure kit for a car but i guess i can rig it to work on the boat. thanks for the advice.

steve

 

[lowpressure68]

Re: 4.3 mercruiser water in oil

it was in the intake manifold.........boat was winterized btw lol. guess it was just time for the old gasket to take a bow.

thanks again

steve

 

[Fordiesel69]

Re: 4.3 mercruiser water in oil

Was it the gasket that blew or the manifold rotted out and allowed water into the vally?