Water entering oil ??????

[al1026]

1984 Mercruiser
4 cylinder
self contained cooling
800 hours on engine

Here in Orlando boat is used often .

Check fluid levels often, engine covered with a tarp besides engine cover making sure everything stays dry


One morning this week after a 3 inches of rain night before within 2 hours, moving trailer too continue installing of new trailer fenders.

I hear water hitting pavement and glancing at drain , I see OIL pouring out of drain plug ????

Holy cow what happened ,?

Day prior everything seemed fine, started engine and ran a few minutes with ear muffs.
Today water and a lot of oil pouring out of drain

Upon further inspection pulled dip stick and oil level extremely high, grayish

Removed oil filter, it was loaded with water like a off white paint
Drained oil and it was the same off white ?????

Thinking with the 3 inches of rain in a short time somehow did water enter ?? There was some water in bilge but remember boat is tilted back, drain open,
no way did water reach engine . Plus with tarp no way could water enter

What would cause oil too come out and drop all over bilge without engine running ?

Self contained cooling that is full and have not had too add water quite sometime

What should I be looking for ?

On the 4 cylinder Mercruiser engine cooling impeller there are gaskets separating oil from water on the shaft.
Water could easily enter but I if I was loosing water I would be filling water tank ?

Was told too add a gallon of diesel fuel or mineral sprits , remove coil wire so engine cant start and crank a few times too clean everything. Wait a short while and drain . Do the same after fresh oil and filter and then start and watch it ???
No oil in engine a few days and do not want too do damage or cause rust too form .

What should I be looking at too stop water from entering my engine ?


thanks
Al

On a self contained cooling were can water enter engine ? .

Could water enter engine from this area since there are a few rubber seals separating oil from water at this point .
Water traveling too engine impeller is self contained water and water level is full
Manifold

He told me too pour a gallon of mineral sprits or diesel gas into engine remove coil wire so engine cant start, crank a few times , let it drop too oil pan and drain
Told me go two ways start pulling things apart but prior add fresh oil & filter and see if it leaks and how long it takes
He did say only two ways water can enter oil ? is that true

So fellow boaters here on this forum what does this sound like and what should I be looking for

 

[stonyloam]

I think you are talking about a 470 engine. There is almost no way for raw water to enter the engine in any quantity. Is the coolant reservoir still full? About the only to get coolant into the engine (not raw water, but antifreeze from the exchanger) is for both camshaft seals to fail and the waterpump weep hole to fail. Are you sure it is water and not antifreeze in the oil? Should be able to smell antifreeze. If the oil came out, I would suspect an external source such as a rusted pan.

 

[al1026]

Terry thanks for your reply
Yes I have the Mercruiser 470

I have a 50/50 mixture anti freeze and tough too smell but as stated reservoir is full
Years ago I made my own bracket using scrap brackets too install a marine alternator removing the stator system
Working in that area I put too much pressure on an aluminum thread bolting down a bracket too support alternator . Would not tighten and water leaked
I removed cover, impeller, Re- Threading whole I installed new o rings, and gasket .
Changing gaskets and making sure weep whole opening was clear
Been fine for years and now when alternator craps out 2 bolts, take alternator too rebuild shop and I am good for few more years .
,
So what you are saying no other way for water too enter
Could it enter thru Manifold gaskets ? Heat exchanger ?
You mentioned crankshaft gaskets ?
I am going too add a gallon of diesel fuel, crank ( not start ) new filter, oil , watch it close .
should I do anything in spark plug area ?

You mentioned external source which I was thinking but have engine covered with tarp except a little short and the elbow area and power steering cooling tube sometimes is exposed but that should not effect water from entering

Al

 

[Bt Doctur]

I hear water hitting pavement and glancing at drain , I see OIL pouring out of drain plug ????
dosent work that way. if you saw oil it was trapped oil washing out of the boat or the oil pan has a hole in it

Day prior everything seemed fine, started engine and ran a few minutes with ear muffs.
Today water and a lot of oil pouring out of drain

Upon further inspection pulled dip stick and oil level extremely high, grayish
Did you check the oil prior to starting the motor, if not the oil had mixed with the water the last time the motor was running.


What should I be looking at too stop water from entering my engine ?
you need to find the entry point first .for plain water to enter the engine it has to come from a high bilge entering thru the oil pan or dipstick or fully submerged entering thru the valve cover or from water duming on the motor from a failed tarp.

 

[stonyloam]

Agree with the Dr. If you have not lost coolant, and you apparently have not, then it must be water. On the 470 the only contact between the engine and raw water is in the exhaust elbow where the warm raw water from the heat exchanger dumps into the exhaust. So it is (I think) impossible for any of that water to get into the engine oil. Look for some external entry point for the water.

 

[achris]

I'm thinking exhaust elbow. If that's corroded through, water will enter a cylinder with an open exhaust valve, then drop passed (albeit slowly, but it will still pass) the piston rings. Hence, water in the oil.

Your seeing oil in the drain water is a completely different problem.... If it's a lot, leaking oil pan (rust hole), if it's just a little, leaking front or rear engine seal, rocker cover gasket etc.

When was the exhaust elbow last checked/changed?

Chris....

 

[stonyloam]

Yeah Chris, if the elbow was corroded at the reservoir it could leak coolant into the cylinder, but he is apparently getting raw water in the oil. If the engine were running it would blow the raw water out the exhaust and if it were not running there would be no raw water flow, maybe a few cc could flow back into the exhaust (unless the muffs were left on for a long time) but not the amount he is talking about. Gotta be a hole someplace (oil in the bilge indicates that) and the water backed up in the bilge (maybe partly plugged transom drain). Best to change the oil and run it to see what happens.

 

[achris]

If the elbow is corroded it will leak seawater into the manifold, then down into the cylinders.... . even with the engine running, water will get sucked back into the cylinders on valve overlap...Seen it happen.. was a big problem on the first of the vortec V6s too. Merc tried a number of way to stop the engine sucking water, including a new module program that had the ignition timing at 0 degrees at idle. There is a fantastic article on exhaust reversion on the web, I'll chase it down and post a link here. elbow design is quite complex to stop it....

Chris......

EDIT: Found it.... It's a pdf so it will load as soon as you click the link...

http://www.michel-christen.com/ExhaustElbows.pdf

 

[stonyloam]

Yeah but this is a 470 ( I think) so the manifold is filled with antifreeze not sea water, and the seawater inlet is downstream in the exhaust. There is just a fitting and an opening for the water to enter the exhaust. So with it running the exhaust will push it out, and even not running any water should just run out of the exhaust because of how the opening is positioned in the elbow. I can see how it could happen in a seawater cooled exhaust, but not in a full closed cooling system. That is assuming the oil is contaminated with seawater and not antifreeze, which seems to be the case here.