Mercruiser - 3.7 ( 470 ) Alpha1 ( please list the sources of CLEAN water in the oil ) about a cup - Antifreeze not leaking - no green in the water -

[chatvmax]

Mercruiser - 3.7 ( 470 ) Alpha1 ( please list the sources of CLEAN water in the oil ) about a cup - Antifreeze not leaking - no green in the water -

 

[Dubed]

Very strange.
You have a closed cooling system on that motor and should be no way to get fresh water in the oil. If your heat exchanger went bad, you could mix coolant with raw water but most likely blow out the exhaust.
There are plenty of ways to get coolant into oil.
I would pressure check your cooling system and see if it holds pressure, and take it from there.

 

[chatvmax]

Very strange.
You have a closed cooling system on that motor and should be no way to get fresh water in the oil. If your heat exchanger went bad, you could mix coolant with raw water but most likely blow out the exhaust.
There are plenty of ways to get coolant into oil.
I would pressure check your cooling system and see if it holds pressure, and take it from there.

thanks for the response,,, ,,
So the oil has not been changed in 2 years, and it sets in a field, all be it motor covered and carb covered,,,, ( Condensation over 2 years in western PA? )
I just changed the oil and ran it 60 seconds and ill dump that oil also as it looks like it picked up the last of what must have been hanging around in oil pan when i ran it to warm it up and flush,,,

So the bad news is the motor was ran with mucky oil for about 30 minutes on the river ,,,
The good news is
1- now i am looking and evaluating so i won't let that happen again,
2- seems to be running fine with great oil pressure and no noises -

 

[Bondo]

So the oil has not been changed in 2 years, and it sets in a field, all be it motor covered and carb covered,,,, ( Condensation over 2 years in western PA? )

Ayuh,..... Welcome Aboard,...... Not sayin' this is yer problem, but I have seen water get into the motor, with the motorbox closed, 'n the carb cover on it, by the water leaking through the seam where the back of the motorbox meets the hull, where it lays on the carb cover, 'n finally leaks down past the center stud that holds the carb cover on, into the intake, into the cylinders, past the rings, into the oil base,......

 

[chatvmax]

Ayuh,..... Welcome Aboard,...... Not sayin' this is yer problem, but I have seen water get into the motor, with the motorbox closed, 'n the carb cover on it, by the water leaking through the seam where the back of the motorbox meets the hull, where it lays on the carb cover, 'n finally leaks down past the center stud that holds the carb cover on, into the intake, into the cylinders, past the rings, into the oil base,......

Well that's quite an exercise in critical thinking AND i looked at it closely ,, it is VERY likely that's what happened here ! AWESOME troubleshooting ! ,,, i will put a strategically placed piece of plastic above to guard this from ever happening,,

Follow-up - if allowed -
Also again its a 470, 3.7, Alpha 1, and i did notice that my voltage at the battery was 13.8vdc at idle and up to 17vdc when 1/4 throttle ( didn't want to go any higher running it on a garden hose ) ,
Question:
1- i have NO electronics , just the points and condenser that runs the engine,, is it an issue if i do NOT replace the OEM water cooled regulator and just leave it alone. ?
- assumption is that thats not a healthy voltage range ,,,

 

[Lou C]

Even though you have closed cooling your exhaust elbow is still raw water cooled, correct? This could be leaking at the gasket between the manifold & elbow or via a hole in the elbow to from the water side to the exhaust side.

 

[Dubed]

Even though you have closed cooling your exhaust elbow is still raw water cooled, correct? This could be leaking at the gasket between the manifold & elbow or via a hole in the elbow to from the water side to the exhaust side.

Yes. My 1st suggestion.. pressure test cooling system. Normally, I think it would blow out the exhaust but yeah, possible. Either way, theres a damaging affect. Pull it, inspect and new gasket
Also a good practice to change the gasket annually and inspect/ dress the gasket surfaces especially on that nla exhaust manifold (if thats what you have). Make it last as long as possible.

 

[chatvmax]

" This could be leaking at the gasket between the manifold & elbow or via a hole in the elbow to from the water side to the exhaust side " - location of elbow...?

I've built motors and I'm not afraid to tackle this type of work, pulling manifolds and such, but just want to understand is there any pictures or any way to better understand this, I will reread but it sounds like I'm pulling just the exhaust manifold off the motor? And this elbow that is discussed, is there a location, does it connect from manifold to motor, picture worth a thousand words here,
Also someone said something about a water pump in the front of the engine that has two seals, my understanding was the water pump itself in the front of the engine could only leak antifreeze into the oil, is that a true statement?
, thank you so very much

 

[Dubed]

"Elbow" is the coolant reservoir. It sits on the exhaust manifold. There are a few different styles depending on year.
The elbow rots out and needs replacing after 5 years or so in salt water, longer in fresh. Do not wait for failure to replace
The manifold fails at the sealing surface that the elbow sits on. It also gets very thin at the #4 cylinder surface area.
Some older ones have a cast iron manifold, and not sure, but I don't think they are available either.

 

[Dubed]

" This could be leaking at the gasket between the manifold & elbow or via a hole in the elbow to from the water side to the exhaust side " - location of elbow...?

I've built motors and I'm not afraid to tackle this type of work, pulling manifolds and such, but just want to understand is there any pictures or any way to better understand this, I will reread but it sounds like I'm pulling just the exhaust manifold off the motor? And this elbow that is discussed, is there a location, does it connect from manifold to motor, picture worth a thousand words here,
Also someone said something about a water pump in the front of the engine that has two seals, my understanding was the water pump itself in the front of the engine could only leak antifreeze into the oil, is that a true statement?
, thank you so very much

There is a weephole under the water pump that will drip or leak when the seals go. Make sure it is free and clear of debris. Run a piece of wire or something up the hole to clear. Some people see it leaking and the plug it up thinking they've solved the problem.
The seals wear a groove on the cam. This is repairable with a speedi sleeve kit if necessary.

 

[chatvmax]

"Elbow" is the coolant reservoir. It sits on the exhaust manifold. There are a few different styles depending on year.
The elbow rots out and needs replacing after 5 years or so in salt water, longer in fresh. Do not wait for failure to replace
The manifold fails at the sealing surface that the elbow sits on. It also gets very thin at the #4 cylinder surface area.
Some older ones have a cast iron manifold, and not sure, but I don't think they are available either.
View attachment 385998

So my understanding is that the actual exhaust manifold may need to be replaced?
So the exhaust manifold can cause clear water to get into the oil?
Or a failing elbow will b causing this ??
Or a failing gasket seal, and if so is it the seal between the elbow and the exhaust manifold, or the seal between the exhaust manifold and the block?

I will drain the antifreeze from the elbow manifold hose connections, take out the bolts that hold that elbow down on top of the exhaust manifold and inspect very closely for any type of holes or cracking, replace the gasket if it's found to be serviceable,,,,, OR are u saying just pull the elbow AND exhaust manifold,,, ?
PS: upon really close inspection I see some water marks like water has drained from the elbow down on top of the exhaust manifold perhaps in the past,,

PS -, additional information, I've owned the boat for 7 years, and have run it in freshwater rivers a few times a year without issues,

 

[chatvmax]

Even though you have closed cooling your exhaust elbow is still raw water cooled, correct? This could be leaking at the gasket between the manifold & elbow or via a hole in the elbow to from the water side to the exhaust side.

My elbow that sits on top of the exhaust manifold has antifreeze in it ,,,

 

[Scott Danforth]

a waterlogged hull sitting low in the water will allow water to migrate to the cylinders thru the exhaust, and will get into the oil

other than that, large quantities of water in the fuel will make it run like crap and may get past the rings at idle.

having water spray on the engine may have water get past the carb.

the 470 is a full system.

 

[nola mike]

Well that's quite an exercise in critical thinking AND i looked at it closely ,, it is VERY likely that's what happened here ! AWESOME troubleshooting ! ,,, i will put a strategically placed piece of plastic above to guard this from ever happening,,

Follow-up - if allowed -
Also again its a 470, 3.7, Alpha 1, and i did notice that my voltage at the battery was 13.8vdc at idle and up to 17vdc when 1/4 throttle ( didn't want to go any higher running it on a garden hose ) ,
Question:
1- i have NO electronics , just the points and condenser that runs the engine,, is it an issue if i do NOT replace the OEM water cooled regulator and just leave it alone. ?
- assumption is that thats not a healthy voltage range ,,,

Check your voltage at the coil, you could burn out your points. If you really want to half ass it, you could put an extra resistor in line to lower the voltage to ~9v. Or you can try one of the cheap voltage regulator fixes that have been proposed in the past.

 

[chatvmax]

I'm the king of half ass, do you have a resistor link, or the values of the resistor I would get? And would that resistor go on the voltage line to the coil?, Also is there a link to cheap ass a voltage regulator? Part numbers?
The issue is I'm flat ass broke this year and lucky to be in the water

 

[flashback]

Ayuh,..... Welcome Aboard,...... Not sayin' this is yer problem, but I have seen water get into the motor, with the motorbox closed, 'n the carb cover on it, by the water leaking through the seam where the back of the motorbox meets the hull, where it lays on the carb cover, 'n finally leaks down past the center stud that holds the carb cover on, into the intake, into the cylinders, past the rings, into the oil base,......

First thing I did was get rid of the plastic umbrella just so I could see what's going on with the real machine...

 

[flashback]

Just get the 9 that @nola mike offered..

 

[Scott Danforth]

NAPA has resistance wire. You need 20-24" of it

 

[Lou C]

My elbow that sits on top of the exhaust manifold has antifreeze in it ,,,

But the water that exits the Heat Exchanger has to be sent thru the elbow to exit over board, correct? If there is a rusted thru area then the water can get into the exhaust gas passage & then into the cylinders/motor oil.

 

[Dubed]

But the water that exits the Heat Exchanger has to be sent thru the elbow to exit over board, correct? If there is a rusted thru area then the water can get into the exhaust gas passage & then into the cylinders/motor oil.

Dark arrow are coolant, white arrows are raw water. It goes in the exchanger, out and thru the p.s. cooler, in and out elbow