5.7 water in engine oil

[peanutbay1]

Ok guys heres the basics:
1990 5.7 mercruiser/alpha 1
The boat sat in dry dock storage for 3 years. The previous owner said he drove it the last day on to the boat yards fork truck running correctly. He also claims a proper winterazation was done as well. We bought the boat 2 weeks ago and got it running. Drained fuel,checked all oils (which looked good) and did a basic tune up. She fires up on a dime,idles smooth and runs clean through the entire RPM range. This past sunday we noticed water in our oil and even what appeared to be oil at a hose leak at the water pump.

Heres the questions:
1) the engine starts,idles and runs on the mark would a cracked block affect this??
2) Could pressure washing the engine with the carb properly bagged cause water to get in the engine??
3) if you were leaking from the internal engine into the cooling system would you not see an oil slik around the boat or have oil mung at the hub??

Our oil pressure is 50 at no wake and 60 underway,our water temp is 125 underway.
What type of testing should we do past compression and vacuum??

Help!!!!!!!

 

[Don S]

Re: 5.7 water in engine oil

He also claims a proper winterazation was done as well.

Sounds like something a seller would say.
How much water are we talking about here?
Even with a cracked block, the engine would run fine, till the water/oil mixture got too full.

 

[Maclin]

Re: 5.7 water in engine oil

The water in the coolant passages is under pressure plus the oil level is not up that high into the block, so oil would not be able enter a cracked internal cooling water passage even if it was up that high because in the crank case it is not under pressure.

You can do a cooling system pressure check on the block if you suspect a cracked block.

What evidence you are looking at to determine you have water in the oil?

 

[Maclin]

Re: 5.7 water in engine oil

Don's post was not there when I started mine, and got distracted, I like his point about it acting normal until the crankcase fills up with water+oil mix, then it comes out anywhere it can until it kills the engine.

 

[peanutbay1]

Re: 5.7 water in engine oil

The way we discovered the oil was that there was about 2 tablespoons of oil on the front of the engine block. Which I thought might be coming from the tapped holes that can leak oil on chevy blocks sometimes. I sealed both this week and first thing this morning i had some oil on the floor again but this time it saw the main hose on the bottom left side of the circ pump on the block leaking what looked like milky oil. I tighted the hose clamp and we drove over to the dock and shut off. I pulled the same hose and it had no oil residue at all and nothing was floating behind us from the hub. I then check the valve covers and sure enough mildly milky oil was on top of the head as well as it seemed to almost be steaming. I also cracked the oil filter and it was deffinatly milky as well. No lie you turn the key and within 1 cranks she fires off and runs fine. I know we have and issue I just need some direction. One other note. I pulled all 8 plugs on saturday and glass beaded and regapped them and all looked the same none were oily or steam washed.

 

[Maclin]

Re: 5.7 water in engine oil

What does the oil on the dipstick look like? What is the level?

Regarding Spark plugs, water in the oil is in the crankcase and not in the "top" of cylinders.

Water in the oil will make the oil level rise and the oil on the dipstick will look like a milkshake. The description of the stuff coming out of your oil filter does sound like water in the crankcase oil. This is usually from cracked internal cooling water passages, a leaking head gasket will just not put that much water in. As the oil level rises the crankcase pressure will force the oil/water mix up into the top of the heads and soon on out the crankcase vent tubing. Usually the level will get so high the engine can no longer run. Up until then it will act pretty normal.

 

[peanutbay1]

Re: 5.7 water in engine oil

the oil on the dipestick at a glance looks like regular oil but when you wipe it on your fingers you can see that it is cloady not what I would call milkshake more like carmel color. As far as the dip stick goes the oil level is above the high mark but I cant tell you if that is the same as last week. Something makes me think the oil level was high last week which is the first time we ran the boat since we got it. I am not trying to avoid what is probably the enevitalbe but by any fringe chance could this be residual moisture from the motor sitting 3 seasons?? How can the hose have zero oil residue in them. How could we see oil for a split few seconds at the circ pump and no oil residue at the back of the boat.

 

[nrob84]

Re: 5.7 water in engine oil

i have a stupid question... i read all of your posts, when you say you did a quick tune up did you change the oil? even if it looks good your supposed to change it every few months because it will get moisture in it from the air. also i believe that it may be possible that from the boat not being run for 3 years seals may have dried out and leaked for a few moments upon startup until they became lubricated. i would change the oil and filter and run it at normal operating temp for atleast 30 mins to get it good and hot to work out any moisture that may have built up in the motor and then check it again... just a few thoughts

edit: i know marine and automotive are VERY different, but, i work as a auto tech and have often seen "steam" come out of a valve cover when the engine is hot and ive taken the fill cap off, not alot but you can see it if you are looking for it. this is concidered normal if the vehicle sits alot or is only used for short trips because it will build up moisture in the block... good luck...

 

[Maclin]

Re: 5.7 water in engine oil

If an engine is run for short periods and does not get up to operating temperature then it will definitely condensate inside the valve cover and in the crankcase some, but it will not be enough to raise the oil level. The primary manifestation of not running long enough is condensation inside the valve cover and the steam mentioned.

Peanut, I am not understanding why you are looking for oil residue in hoses. No oil evident in hoses is not a valid test for the health of an engine. If there is oil in the hoses then something is very very wrong, but conversely no oil in the hoses does not mean all is well. The oil will not come out any cooling hoses, that is not what happens when a block is iinternally cracked. Cooling water gets into the crankcase and raises the oil level and creates an emulsion harmful to the engine's lubrcated parts, but oil will not enter the cooling passages. Change the oil and run it again with a known starting point for the oil level. You can't hurt it much more than it is already.

Oil at the recirculating pump is probably from a timing cover pinhole or leak or other failed gasketing in the area. That will not put oil into the hoses either.

 

[peanutbay1]

Re: 5.7 water in engine oil

OK guys I will give you the very brief story of this boat. My brother and I picked her up 2 weeks ago in Md. She is 28ft and had a ton of things to be done to try to float and run her. I checked the oil which was golden and from what I remember on the high side of the dip stick. Our plan was to get the boat running,test her out and then decide our course of action for repairs. I have been boating for 22 years and I understand about the importance of good fluids. But as you can understand before you spend dime one on a boat you need to make sure she is worth the effort. All that being said I will follow the advice of oil removel,re fill and checking of the level. As far as the coolant hose I refered to. I was head first down in the engine compartment while my brother operated the boat at about 4500 WOT. That is when I thought I found the leak which was the lower coolant hose on the circ pump. I swear to god I saw milky oil coming out of it. I tightened the clamp cleaned the oil off the floor and we proceeded to the dock. It was less than 5 minutes. Upon arrival I pulled the same hose that seamed to be leaking milky oil and the hose and pump barb were completely clean no oil residue just water. Not even a small amount of residue. I checked out behind the boat at idle to see if we would make an oil slick based off the fact that oil was in the circ pump hose which ultimately ends up over board via the hub and I checked the prop hub for any oily feel and it was dry. I am not trying to talk the group into the idea that its not a cracked block I just want to be sure and test any avenues that you guys might think to try. What about the thermostat housing on top of the int. manifold towards the front. I read about those leaking through into the valley. We pulled our upper hosed with the ball checks in them and even though the engine looks beautiful the balls and seats were very corroded. This could be an indicator about the block. What is bizarre is the engine seariously looks cleaner than most. Confused!!!!

 

[Maclin]

Re: 5.7 water in engine oil

You can do a cooling system pressure check on the block if you suspect a cracked block.

This test will tell you if the block is ok or not. A rusted thru intake would also show up on this test.

 

[peanutbay1]

Re: 5.7 water in engine oil

I have read about this test but never done it. Can you give me the procedure on how to do this??

 

[peanutbay1]

Re: 5.7 water in engine oil

I have read about this test but never done it. Can you give me the procedure on how to do this??

 

[Maclin]

Re: 5.7 water in engine oil

It is the same test as done in automotive applications where a hand air pump with gauge designed for this is used to put pressure into the cooling pasages, like 5-7 pounds, then you time how long that pressure can hold. If it does not hold at all then you can use a stethoscope to listen around the block and get an idea where the air is escaping from.

For Marine tests you have to get a little creative on how and where you plumb in the hand pump and what hoses to block off so the pressure pumped in stays in the cooling system.

 

[zbnutcase]

Re: 5.7 water in engine oil

I say pull the intake and check for cracks in the valley. 'nutcase

 

[peanutbay1]

Re: 5.7 water in engine oil

INFORMATION UPDATE:

I forgot a big detail about this engine. When we first started it we found the circ pump to be completely wasted. The front sheave wobbled and it sounded like ball bearings in a can. So we put a new marine water pump on the engine and a new water pump in the lower unit. Here is why I am explaning this...when the engine first fired (before pump replacement) we found no water leaking out the circ pump shaft which seemed odd and made us decide to rebuild the lower unit water pump in addition. When we pulled the lower unit pump it was fine but we replaced it anyway. I keep wondering if by some strange chance the oil may have had water from sitting 3 seasons and of course was seperated so I would have seen clean oil on the dipstick. I have been looking at photos of milky oil all day and I would say we barley qualify as milky which makes me supsect of the quanity of water in the oil. I will conduct the tests reccomended I just hate to bail on this motor as it runs perfect and looks great. I guess the test results will tell the story. I will keep you posted.

 

[bruceb58]

Re: 5.7 water in engine oil

Run the engine until it is warm and then change the oil. If the engine compartment had ever gotten full of water high enough to hit the front or rear seal you could also gotten some tiny amount of water in the engine.

 

[peanutbay1]

Re: 5.7 water in engine oil

TESTING UPDATE:

I ran a series of tests last night here are the results.

compression test 165-170psi all 8 cyl.
plug condition: indentical and correct looking,no water or rust.

vacuum test; 15hg as per merc. manual SPOT ON PERFECT.

Oil change process;
1) Ran engine to op. temp. and drained oil (pics included). exactly 5 qts of oil was removed which I expected more if I was filling the engine with water.
2) changed oil and filter and took note of oil level. I ran the engine for 30 minutes and checked the oil. Golden clear and NO LEVEL RISE.
3) I let the engine set for 10 minutes and checked the level again. It was actually just a hair below the enitial fill which was obviously caused by the filter filling up completly.
4) I ran the engine at 1500rpm for 5 minutes. 60psi oil pressure 160 water temp.

Upon completion of the process I looked in the valve covers and saw clean oil with just a droplet of water here or there which I am assuming is caused by the remaining water turning to condensate in the valve covers. I also looked down through the carb into the intake manifold just to see anything and its clean casting no rust no oil crap.

Questions;
1) What do you think????
2) Should I change the oil again or run this batch this sunday and then change it. The oil is 5w-30 automotive oil not the quicksilver oil I always use.
3) Is it possible because this boat sat for 3 seasons along the river in MD that it could have picked up enough moisture from the surrounding enviornment??

Thanks in advance for helping.

 

[airdvr1227]

Re: 5.7 water in engine oil

Running it with the oil you put in won't hurt anything. Only way to know is to take her out and run her hard.

 

[Maclin]

Re: 5.7 water in engine oil

Those pics look like the oil was contaminated, probably water. But your test runs sound like good news. Based on the pics that show what it was like when you ran it before this oil change I think I would change the oil and filter one more time and then run it on the lake hard as just suggested. Alternately you could run it now and see how it turns out, but I would definitely change it after that, good luck .