87 mercruiser 470 fresh water in oil???????

[SHANEWHITLEDGE]

Recentlly purchased an 87 searay with 470 mercruiser i/o for $300.00 that had a known blown head gasket that was noticeable upon removing the head. Also i had the head pressure tested, resurfaced, and a complete valve job done. Reinstalled with factory oem head,exhaust, and intake gaskets. Drained all old milky oil completely and refilled oil and coolant. Boat cranks up and idles perfectly, ran it for about an hour with fresh water supply to the foot which has a new water pump also. Decided to change oil again just to be safe and get all milky oil out. New oil after hour is very milky, more so than if it just mixed with leftover old oil. Coolant level is still perfect. So im guessing that the fresh water supply is getting in somehow. Also noticed small amount of fresh water mixed with exhaust gases coming out of exhaust bellow too while running. Any answers, suggestions, ideas, or tips, on what is wrong or how to fix this???????????????????

 

[thrttlebkhtrod]

Re: 87 mercruiser 470 fresh water in oil???????

Welcome to iboats, heres a link to the adult section to give you some insight on your issue, Just from a personal experiance with the same issue. I am in the process of replacing my motor. Good luck

http://forums.iboats.com/showthread.php?t=369864

 

[Bt Doctur]

Re: 87 mercruiser 470 fresh water in oil???????

fresh water cant get into the engine ,engine is cooled by a 50/50 mix of A/F ,unless you have the wrong gasket on the riser/elbow
mixing the water from the muffs with the mixed A/F.
simply changing oil will never remove all the water, motor neeeds to run at normal temp to remove the moisture from the oil.at least an hr`s run

 

[SHANEWHITLEDGE]

Re: 87 mercruiser 470 fresh water in oil???????

Ok after researching it i do believe fresh water supply cannot seap into crankcase. So i flushed the engine crankase and refilled oil. Topped off coolant. And ran motor for approx 30 mins. Did notice coolant level dropped approx 2 inches during this time. After shutting engine off i waited approx ten mins before checking oil level. Oil level is perfect at the fill mark and looks super clean. But wear did coolant go ? Plan on draining oil again in the morning just to satisfy my curiosity. And if it is milky this time i agree collant is getting in somehow, even after all the head work and new gaskets, flushing out motor and two oil changes. Where is it possibly finding its way into my oil. Real puzzler to me beings that the motor runs so perfect and smooth.

 

[Bt Doctur]

Re: 87 mercruiser 470 fresh water in oil???????

if it went into the engine the 2 inches would have contaminated the oil,so if the oils still clean I suspect you may have just overfilled the heat exchanger . most times the cold level is about 2 inches below the neck. if the coolant loss is constant, check the HE for leakage into the seawater side of it.

 

[stonyloam]

Re: 87 mercruiser 470 fresh water in oil???????

Did you retorque the head bolts after bringing it up to temperature? Check your coolant expansion tank. The hose to the tank from the reservoir, any leak in that line and when the engine cools it will fail to draw the coolant back into the reservoir. Do a coolant system pressure test (borrow tools from Autozone). Also it may take a while to work all of the air out of the system.

 

[SHANEWHITLEDGE]

Re: 87 mercruiser 470 fresh water in oil???????

Did retork head bolts after engine ran. Also this morning oil level on dipstick was 1/4 inch past full mark. So i removed the drain plug and yep milky oil again.

 

[stonyloam]

Re: 87 mercruiser 470 fresh water in oil???????

Is the weep hole in the engine waterpump clear? Can you smell antifreeze in the oil?

 

[SHANEWHITLEDGE]

Re: 87 mercruiser 470 fresh water in oil???????

Guess what? Finally after removing the coolant over flow tank and its bracket i managed to find where the weep hole was suppose to be. Its there all right but some genius put a screw covered in permatex in the hole.which tells me it was leaking there before i got the boat. So after about an hour i had removed the water impeller housing, rotor, stator and timing cover to reveal bad inner and outer cam seals and crank seal. At least cam shaft was smooth and not grooved. So i ordered a kit today to replace all the seals ans gaskets. Gonna have a buddy at a machine shop press them out/in for me. Any other suggestions ,hints, tricks to make this job successful are greatly appreciated. Thanks for all assistance so far

 

[stonyloam]

Re: 87 mercruiser 470 fresh water in oil???????

Yeah, That is kind of what I expected. FYI it is designed this way: The first seal seals in the coolant which is under pressure, and when it starts to leak the pressurized coolant comes through into the space between the seals where it dribbles out of the weep hole under essentially no pressure to force it past the second seal. In your case it had no where to go and no way to relieve the pressure so when the second seal failed it went into the engine. One more thing the antifreeze will do a number on the engine bearings (much worse than water as I understand it) so get it out of there ASAP change the filter and put in some cheap oil, run up to temperature and do it again with another filter and good oil. If you need perfect seal for the gaskets NAPA (permatex) aviation sealant is a good substitute. Good luck! Oh yeah, be careful not to overtorque the waterpump and timing chain covers when you put them back on, they crack easily (don't ask how I know:facepalm.

 

[fmalott]

Re: 87 mercruiser 470 fresh water in oil???????

i also learnt a lesson when putting new gaskets on the timing cover and impeller do not buy the cheap gasket kit i did and before i even got it back to the water the gaskets where leaking they where the paper kind so i went and bought the proper gaskets they where made out of the ones like they had metal in them works great

 

[achris]

Re: 87 mercruiser 470 fresh water in oil???????

As for flushing the old oil/water mix... I'd dump a pile of diesel in the engine, remove the spark plugs and ground the points so you get NO spark. Then crank the engine for a couple of minutes to circulate the diesel, then dump it... Do it again, and dump it... Then put fresh (cheap) oil in and run the engine for 5 minutes (maximum), dump that, and that should see most of the water gone... Then fill with cheap oil again and take the boat out for about a 1 hour run... do an oil change and you should be good to go.... New filter at each change (get a real cheapy from a car shop)...

I know it's a PITA, but it's cheaper than a strip and replace bearings....

Chris........

 

[fmalott]

Re: 87 mercruiser 470 fresh water in oil???????

As for flushing the old oil/water mix... I'd dump a pile of diesel in the engine, remove the spark plugs and ground the points so you get NO spark. Then crank the engine for a couple of minutes to circulate the diesel, then dump it... Do it again, and dump it... Then put fresh (cheap) oil in and run the engine for 5 minutes (maximum), dump that, and that should see most of the water gone... Then fill with cheap oil again and take the boat out for about a 1 hour run... do an oil change and you should be good to go.... New filter at each change (get a real cheapy from a car shop)...

I know it's a PITA, but it's cheaper than a strip and replace bearings....

Chris........

i also heard putting trany fluid in the oil it's suppose to help clean out all the crud that builds up in the motor when you take it out for the 1 hour run then change oil

 

[achris]

Re: 87 mercruiser 470 fresh water in oil???????

i also heard putting trany fluid in the oil it's suppose to help clean out all the crud that builds up in the motor when you take it out for the 1 hour run then change oil

Not keen on tranny fluid, it's too abrasive... Good as a hydraulic fluid, but not so good as a general lubricant... especially when high shear loads are involved...

Chris.......