Water in engine oil Mercruiser 260

[mizmore150]

My 1984 Mercuriser 260 (alpha 1 outdrive probably) has been starting hard (barely turning over when cold). I checked the oil in the dipstick, it was fine. I noticed some "mayonaise" in the oil fill on both valve covers and thought it was condensation but when i took the boat out it was running a bit rough so i checked the oil and it was milky. The oil level was about 1.5 inches above full. I have 2 questions

1. (a dumb question) I just had the seals replaced in the outdrive, could the mechanic have done anything to cause this?

2. Where do i go from here? I'm not much of a mechanic but i can do enough to get into trouble.

I should mention that the block had supposedly been cracked and repaired before i purchased the boat (down near the bottom of the block on either side). I have ran the boat for 1.5 seasons with no problems.

 

[Bondo]

Re: Water in engine oil Mercruiser 260

Ayuh,..... Welcome Aboard Mizmore,....

#1,.. Nope....

#2,.. It sounds like te Band-aid Failed...... A Closer Inspect is probably warranted.....

 

[ziggy]

Re: Water in engine oil Mercruiser 260

Where do i go from here?

this'll be a good start...


http://www.boatfix.com/merc/Bullet/01/01_10.pdf


http://www.boatfix.com/merc/Bullet/01/01_13.pdf

I just had the seals replaced in the outdrive, could the mechanic have done anything to cause this?

not likely.. there 2 different entities.....
the cracked block could though....

 

[mizmore150]

Re: Water in engine oil Mercruiser 260

Thankyou ziggy
Those links were very helpful.
It is probably wishful thinking but i do have a swim deck, and my symptoms do match the "boat's waterline" section of that service bulliten.
Do you think water could have forced its way up somewhere it should'nt have gone when i deccelarated? If so how do i adequately remove the oil from the engine, especially under the valve cover. (there is "mayonaise" all over in there.)
y'all are awesome
Mizmore150

 

[RJLeuwen]

Re: Water in engine oil Mercruiser 260

My 1984 Mercuriser 260 (alpha 1 outdrive probably) has been starting hard (barely turning over when cold).

Sounds more like you are geting water in the cylinders, then from a crack in the block.

Unless the block was cracked internally and patched (which most of the time fails) Take all of the spark plugs out and see if they have any water in them.


RJ

 

[mizmore150]

Re: Water in engine oil Mercruiser 260

I changed the oil and ran the motor for about 35 minutes. The dipstick looks good with only clear oil on it.

I did find water in some of the cylinders on both sides of the motor.

there is milky oil at the top of the motor (near the lift springs)

Diagnosis anyone?

 

[Bondo]

Re: Water in engine oil Mercruiser 260

Ayuh,.....

It sounds like You're in the market for a 350 Chevy......

 

[mizmore150]

Re: Water in engine oil Mercruiser 260

Ayuh,.....

It sounds like You're in the market for a 350 Chevy......

Speaking of that I have a 92 chevy van with a good running 350 in it.
any way of converting that or at least using the block

 

[Bondo]

Re: Water in engine oil Mercruiser 260

Ayuh,...

Not that it Couldn't be done,...
But,...
You'd run into a few glitches because of the change in the Crankshaft Rear Main Seals that happened in 86/87....

 

[mizmore150]

Re: Water in engine oil Mercruiser 260

i think i'll just have a shop build me a new motor.

since my block is bad (84 mercruiser) what year, make, model of 350 should i look for.

 

[mizmore150]

Re: Water in engine oil Mercruiser 260

Ok I pulled a head and found that i have a burnt out exhaust valve. (explains the "0"lbs. compressionh) This should explain why i have water on top of the pistons, and water in the engine oil. I plan on grinding the valves and seats, and replacing the bad exaust valve.


Compression was: (left side of motor, front to back) 90,0,120,135
(right side of motor, front to back) 130,120,125,135

2 questions:

1. should i pull the other head if compression was ok
2. If i dont pull the other head, do i need to remove the intake manifold to properly seat and seal the head.

Thanks,
Mizmore150

 

[Bondo]

Re: Water in engine oil Mercruiser 260

This should explain why i have water on top of the pistons, and water in the engine oil.

Ayuh,... How's That,..??

1),.. Your Choice,... I would....

2),.. Yes... It should already be Off...

 

[RJLeuwen]

Re: Water in engine oil Mercruiser 260

I would take both heads to a good machine shop and have them checked for cracks, do all the valves, and see your compression come back up to aleast 150 lbs.

RJ

 

[mizmore150]

Re: Water in engine oil Mercruiser 260

Ayuh,... How's That,..??

1),.. Your Choice,... I would....

2),.. Yes... It should already be Off...

That mercruiser service bulliten you sent me said that a bad exhaust valve will create a vacuum and draw water and exhaust back into the cylinders and then when the engine is not running water will pass the rings into the crankase. Yes? No?

 

[mizmore150]

Re: Water in engine oil Mercruiser 260

sorry bondo it wasnt you that sent me that link it was ziggy. (see above)