? About water in oil

[markhodges78]

1994 mercruiser 3.0 Thursday evening heading back in after being on the water all day I noticed my speed was about 2 miles an hour lower.
I thought no big deal the water is choppy maybe that's it.
When I got to the truck the boat was idling ruff and I thought it may have sucked something into the carb no biggie.
The next day I went out fishing and after unloading the bout I hit the key and it acted like the battery was weak and then it started up out on the water it was running ruff so I thought I would take the idle screw out run engine and put it back in.
When I opened the hatch and took the breather off of the carb I seen milky oil around where the breather sets.
I checked the oil and it was all up the stick I headed back in and the boat had lost all speed I'm now running 23 mph top speed.
I pulled the plugs and had water in cylinder 1 and 2 the engine did not run hot 160 is what it runs.
I took the head off today and cant see how the water was getting into the cylinder but both cylinder 1 and 2 had water in them... is there anything I should look for before replacing gasket and putting head back on ... I only need to get a few more months from this engine and then I'm converting boat to a v6 sorry so long ... also the manifold and elbow was replaced last year...

 

[Scott Danforth]

Salt water? If so, check the exhaust manifold

 

[markhodges78]

Fresh water only and the manifold and elbow where replaced and only have 15 hours on them... also I only have water in 2 cylinders

 

[Scott Danforth]

Do a pressure test of the cooling water jacket, do a compression test and leak down test

 

[stresspoint]

im not that familiar with the 3.0 so my ideas of what's gone wrong and where to look is in general .

split /crack in engine block.
cracked or rotted cylinder head.
manifold risers ( replaced recently but gasket can fail from over heat ).
reverb , sucking water from a bad flapper.
disgruntled neighbour tipped water down the carb .

 

[markhodges78]

I fish 2 times a week this time of year and the boat has been fine it was good all day on Thursday when I fished.
The problem started while coming back in from a 30 minute run up river its never overheated.
I replaced the manifold and elbow as part of preventive maintenance and the exhust flaper is new as well. I did check it and it's still in tach and functional.
I did a compression test and cylinder 1 was 120 cylinder 2 was 180 but but went down after all the water was expelled and 3 and 4 were 150. Also I could see compression coming from the were the j hose connects to the water pump while I was checking compression.

On another note if it's something going on with the manifold Wouldn't I have water in all cylinders?

Thanks Mark

 

[Scott Danforth]

Did a compression test and cylinder 1 was 120 cylinder 2 was 180 but but went down after all the water was expelled and 3 and 4 were 150.

Anything over 150 is water or oil in the cylinders

The 120 may be rust

With all at 150 psi, you can rule out head gasket

On another note if it's something going on with the manifold Wouldn't I have water in all cylinders?

No. You will get water in the cylinders that are either directly under your gasket leak. Usually only 1 or 2 cylinders

Regarding the manifold and elbow

Fresh water only and the manifold and elbow where replaced and only have 15 hours on them... also I only have water in 2 cylinders

If you used an off-brand and not a Mercruiser, Osco, or Barr, you have to true up the mating surfaces with a belt sander it a large file. Most off shore (read as chineseum) are not flat. Verify with a straight edge

If you bought from Sierra, they are Chinese castings until their castings from the Osco venture start. Also the Sierra green gaskets have been called the "green leakers" for a reason

I would still rule out a crack by pressure testing the cooling water jacket. However willing to bet you have a leaking elbow gasket

 

[markhodges78]

No. You will get water in the cylinders that are either directly under your gasket leak. Usually only 1 or 2 cylinders

The 2 cylinders with water in them are the farthest from the elbows it's the 2 front cylinders and the elbow is in the back

Also if it was the manifold or exust why is compression escaping from the thermostat housing

And yes the kit was a barr kit with the metal looking gasket

 

[markhodges78]

I will pressure check the jacket when I get the head back on

 

[stresspoint]

a pressure test of the cooling system will determine a bad head gasket , cracked head or a split cylinder block.

whack it back together , use a OEM head gasket and hope its good to get you out fishing till you swap out the motor.

 

[Bondo]

I will pressure check the jacket when I get the head back on

Ayuh,..... If you've got the head off, have it magna-fluxed, 'n checked for a crack,.....

 

[markhodges78]

Ayuh,..... If you've got the head off, have it magna-fluxed, 'n checked for a crack,.....

My first thought was to do this but my machine shop is 3 weeks out to get to it so I figured a $50 head gasket and if the problem is still there then my season is over so I'll just pull the engine and start getting ready for the 4.3...

Maybe I dumb way to go about it but I'm really only trying to get a few more months out of engine.. I do have another engine that hasn't been run in years that I could pull the head off of..

 

[markhodges78]

Ok so got the head back on the boat and run the engine on the muffs but ended up with the same problem ( water getting in cylinders 1 and 2 after just a few minuts of running ) so i made a few videos for you guys to show whats happening

video 1 is showing combustion coming from the thermostat housing with plugs only in cylinder 1 and 2

New video by Mark Hodges

photos.app.goo.gl

video 2 is showing no combustion coming from the thermostat housing with plugs only in cylinder 3 and 4

New video by Mark Hodges

photos.app.goo.gl

video 3 is showing the block drain with no plugs in the engine

New video by Mark Hodges

photos.app.goo.gl

video 4 is showing the block drain with plugs in cylinders 1 and 2

New video by Mark Hodges

photos.app.goo.gl

I beleive this is a cracked block or a cracked head but do not beleive it to be an issuie with the manifold. What do you guys think ?

 

[stresspoint]

Ok so got the head back on the boat and run the engine on the muffs but ended up with the same problem ( water getting in cylinders 1 and 2 after just a few minuts of running ) so i made a few videos for you guys to show whats happening

video 1 is showing combustion coming from the thermostat housing with plugs only in cylinder 1 and 2

New video by Mark Hodges

photos.app.goo.gl

video 2 is showing no combustion coming from the thermostat housing with plugs only in cylinder 3 and 4

New video by Mark Hodges

photos.app.goo.gl

video 3 is showing the block drain with no plugs in the engine

New video by Mark Hodges

photos.app.goo.gl

video 4 is showing the block drain with plugs in cylinders 1 and 2

New video by Mark Hodges

photos.app.goo.gl

I beleive this is a cracked block or a cracked head but do not beleive it to be an issuie with the manifold. What do you guys think ?

cracked block ? ,THAT SUX , oh well it was worth a shot ..

 

[Scott Danforth]

pressure test the cooling water jacket and check

was the head checked for cracks?
is the deck and head flat?

 

[markhodges78]

cracked block ? ,THAT SUX , oh well it was worth a shot ..

Thats what im thinking. I was fine all day untill the 30 minute run back up river. I guess maybe a weak spot in the block

 

[markhodges78]

pressure test the cooling water jacket and check

Thats on the agenda for tomorrow

was the head checked for cracks?

no this was a cross your fingers and hope for the best trying to finish to last few months of my fishing season and my machine shop is 3 weeks out

is the deck and head flat?

not sure i couldnt imaging i wouldnt be this engine has never ran hot

 

[markhodges78]

Found the problem theres a hole in the head right behind the thermostat housing

 

[stresspoint]

ha ha , buff it out and plug it up with some belzona ..(joke , although Hmmmm ).

at least its not the engine block cracked , you can now stick that spare head you mentioned and go fishin .

 

[tank1949]

Found the problem theres a hole in the head right behind the thermostat housing

If saltwater block, expect inside block to look like this as well.... Cancer is cancer.