95 Mercruiser 4.3 water in oil

[Jerm8]

I'm a newbie to this forum. I went to wake my boat up from her winter slumber and when I pulled the dipstick...to my dismay the oil was a bit foamy. I've owned this boat for 22 years and have done all of the maintenance/winterizations and never had an issue up here in Montana. That being said, I really can't remember pulling the dipstick last fall when I winterized her.
So I started pumping the water....I mean oil out and and there was aprox. a quart of water in the pan. I put in fresh oil and a filter with the idea of starting it up to see how quickly it got foamy. It was hydro locked. I didn't have time to do anything further at that moment.
I started into it yesterday and pulled the plugs. Both of the back cylinders had water in them. I cranked it over for a few seconds to try to get all of the water out.
Today I pulled the intake manifold. Here's a couple pics.
At first glance it looks to me like it must not have ran much with water in the oil. I expected to see some milk. The intake gasket appears intact to me as well and I don't see obvious cracks anywhere.
Any thoughts on this? It doesn't make sense to me that both head gaskets...or heads cracked at the same time and only let water into the back cylinder on each side...but I could certainly be wrong. To my knowledge it hasn't overheated.
Any advice would be much appreciated!

Jeremy

 

[tank1949]

22 years old? Was hatch open so that there was a possibility of rainwater getting into motor? Water over dam now, but before pulling parts, you should have performed compression test. It might have told you where to begin. That old of motor, I suspect it is time for tear down, and totally rebuild. A good machine shop should be able to test parts and rebuild them, unless block cracked.

 

[alldodge]

Could still do a compression test with intake off.
Make a couple block off plates for the intake ports and pressure test the block thru the drain plug. See if it holds air, and if it does might be worth a try to reinstall the intake and run it

 

[poconojoe]

Pardon my ignorance.
In the first picture, what is that shaft looking thing with the cylindrical part on the left and flat plate part on the right?
Some kind of water passage?

 

[Scott Danforth]

Pardon my ignorance.
In the first picture, what is that shaft looking thing with the cylindrical part on the left and flat plate part on the right?
Some kind of water passage?

Balance shaft

 

[Scott Danforth]

Having water in the cylinders is an indicator of failed winterization or failed exhaust manifolds

The pic of your motor shows moisture in the intake ports

Do a compression test

How did you do your winterization?

 

[poconojoe]

Balance shaft

Thanks!
I'm assuming it spins.
Doesn't look like it does with that bent tubing turning down toward the left of the picture.
Does the whole thing spin or just the paddle looking piece?
I'm guessing it's driven by the water pump?

Can you explain exactly why it is needed? Is it exclusive to the 4.3? Or maybe for V6's in general?

Thanks again.
I don't mean to high Jack this thread, but it caught my eye and I've never seen that.

 

[Lou C]

It’s odd that this would happen given that you did the winterizing all those years & never had a problem. Do you manually drain & leave dry or back fill with antifreeze? Is it possible that water got in & ran down the intake manifold? If the boat is stored with the bow up I’m wondering if failed exhaust manifold gaskets let water or AF in.
Last question if you use AF if it gets really cold where you are like below zero I don’t think the cheaper -50 or -60 stuff is adequate you would want to use -100 in that case.

 

[Lou C]

Thanks!
I'm assuming it spins.
Doesn't look like it does with that bent tubing turning down toward the left of the picture.
Does the whole thing spin or just the paddle looking piece?
I'm guessing it's driven by the water pump?

Can you explain exactly why it is needed? Is it exclusive to the 4.3? Or maybe for V6's in general?

Thanks again.
I don't mean to high Jack this thread, but it caught my eye and I've never seen that.

It is run off the camshaft. GM found that even after adding an even fire (split journal) crankshaft to the naturally unbalanced 90* V6 there were still vibrations so the balance shaft removed the rest of those. I think they were added in ‘95. Vortec heads came in ‘96.
My old ‘88 doesn’t have it and there is a definite vib you feel and can see like a front to back shake but the soft engine mounts damp it out mostly. Some prefer the non balance shaft version because it takes some power to turn….

 

[Scott06]

I'm a newbie to this forum. I went to wake my boat up from her winter slumber and when I pulled the dipstick...to my dismay the oil was a bit foamy. I've owned this boat for 22 years and have done all of the maintenance/winterizations and never had an issue up here in Montana. That being said, I really can't remember pulling the dipstick last fall when I winterized her.
So I started pumping the water....I mean oil out and and there was aprox. a quart of water in the pan. I put in fresh oil and a filter with the idea of starting it up to see how quickly it got foamy. It was hydro locked. I didn't have time to do anything further at that moment.
I started into it yesterday and pulled the plugs. Both of the back cylinders had water in them. I cranked it over for a few seconds to try to get all of the water out.
Today I pulled the intake manifold. Here's a couple pics.
At first glance it looks to me like it must not have ran much with water in the oil. I expected to see some milk. The intake gasket appears intact to me as well and I don't see obvious cracks anywhere.
Any thoughts on this? It doesn't make sense to me that both head gaskets...or heads cracked at the same time and only let water into the back cylinder on each side...but I could certainly be wrong. To my knowledge it hasn't overheated.
Any advice would be much appreciated!

Jeremy
View attachment 368478View attachment 368479

Looks to me like water ran down the intake and filled the cylinders

Oil side of engine looks clean normally when water is in the oil and it’s run you get a creamy milkshake on oil side not what you see here can only think water got in doghouse or if shrink wrapped you had condensation inside that got in engine


You may be able to free it up but would bet there is rust in cylinder walls and valves are stuck

 

[Jerm8]

It’s odd that this would happen given that you did the winterizing all those years & never had a problem. Do you manually drain & leave dry or back fill with antifreeze? Is it possible that water got in & ran down the intake manifold? If the boat is stored with the bow up I’m wondering if failed exhaust manifold gaskets let water or AF in.
Last question if you use AF if it gets really cold where you are like below zero I don’t think the cheaper -50 or -60 stuff is adequate you would want to use -100 in that case.

I haven't back filled with antifreeze. I pull the block plugs, exhaust manifold plugs and remove hoses to drain everything and leave them out for the winter. I shrink wrap it and leave a couple vents to prevent condensation. It also has the engine cover in place so there really isn't any way for water that may find its way under the shrink wrap to get to the engine. I don't store with the bow up.

 

[Lou C]

Looks to me like water ran down the intake and filled the cylinders

Oil side of engine looks clean normally when water is in the oil and it’s run you get a creamy milkshake on oil side not what you see here can only think water got in doghouse or if shrink wrapped you had condensation inside that got in engine


You may be able to free it up but would bet there is rust in cylinder walls and valves are stuck

Agreed that pic does not look like what you have when water gets into the oil from failed head gaskets or even intake gaskets. Was there corrosion inside the carb?

 

[Jerm8]

Looks to me like water ran down the intake and filled the cylinders

Oil side of engine looks clean normally when water is in the oil and it’s run you get a creamy milkshake on oil side not what you see here can only think water got in doghouse or if shrink wrapped you had condensation inside that got in engine


You may be able to free it up but would bet there is rust in cylinder walls and valves are stuck

Not sure what you mean by doghouse. It was shrink wrapped with vent holes. Could condensation create that much volume...filling 2 cylinders and about a quart of water in the oil pan?

 

[Lou C]

I haven't back filled with antifreeze. I pull the block plugs, exhaust manifold plugs and remove hoses to drain everything and leave them out for the winter. I shrink wrap it and leave a couple vents to prevent condensation. It also has the engine cover in place so there really isn't any way for water that may find its way under the shrink wrap to get to the engine. I don't store with the bow up.

When you pulled the plugs do you poke em with a pick or similar to make sure rust flakes aren’t clogging the drains? Any suspicious rust stains on the manifolds or block suggesting freeze damage?

 

[Scott06]

Agreed that pic does not look like what you have when water gets into the oil from failed head gaskets or even intake gaskets. Was there corrosion inside the carb?

When I janked the cracked block from PO on my boat the oil was so milky it wouldn’t drain … it was a PITA to scrub out of the hill as he blew it out the valve covers … very different from what’s seen here and there is rust in intake passages

 

[Lou C]

Not sure what you mean by doghouse. It was shrink wrapped with vent holes. Could condensation create that much volume...filling 2 cylinders and about a quart of water in the oil pan?

Dog house is a style of engine cover some boats have with small jump seats on either side of the engine. Instead of the big Sun pad….

 

[Scott06]

Not sure what you mean by doghouse. It was shrink wrapped with vent holes. Could condensation create that much volume...filling 2 cylinders and about a quart of water in the oil pan?

Doghouse is engine cover cowling slang

It could if enough was present

My dad pulled my boat one fall due to low water levels , covered it in the yard but left plug in , wasn’t much water in bilge but evrything under the boat cover had a layer of condensate on it two weeks later when I winterized it

Clearly from rust stains you had water in the intake passages

 

[Lou C]

When I jammed the cracked block from PO on my boat the oil was so milky it wouldn’t drain … it was a PITA to scrub out of the hill as he blew it out the valve covers … very different from what’s seen here and there is rust in intake passages

On mine when the HGs blew the cam valley, valve covers had milky oil everywhere but no rust in the intake passages as seen there. I did get the water out & changed oil 3/4 times within a week though. Salt water doesn’t forgive!

 

[Rick Stephens]

If it didn't run in from the carburetor, and it sounds like not, then you need to reinstall the intake and pressure test the block cooling system. To my eyes the intake gaskets were pretty pristine and unlikely to be the issue.

If the block passes the test then Occam's Razor says look at the exhaust manifolds since they are all that is left.

 

[Lou C]

This is what mine looked like when the water got in from the HGs, after cleaning most of it up, notice the cyl head intake ports don't have rust in them, not like those in the pic above (remember salt water engine here). If you look close you can still see some of hte milky oil