Water in engine oil 4.3L

[joejffrs]

Doing beginning of season oil change the engine oil came out grey and thick. Last run a few months ago. Boat is a 1993 Maxum 4.3 LX Mercruiser, I bought it new, has relatively low hours; about 20 hours a year. All other yearly oil changes were clear oil. Probably will start with pulling heads, having them checked, and replacing head gaskets. Any other suggestions on what to check? As far as car motors I can figure out how water can get into oil but boats have so many other ways I'm sure!!
Thanks for any help.
Joe

 

[alldodge]

grey and thick

You sure its water, did you use pink antifreeze?
If the motor will turn over I would do a compression test before pulling heads, then pressure test the cooling system.

I would also recommend changing oil during winterization, want to get all those combustion byproducts out before winter

 

[Scott Danforth]

Please explain how you winterized your motor

 

[joejffrs]

You sure its water, did you use pink antifreeze?
If the motor will turn over I would do a compression test before pulling heads, then pressure test the cooling system.

I would also recommend changing oil during winterization, want to get all those combustion byproducts out before winter

The boat does not have a closed cooling system so there is no coolant. I will have a good compression gauge here tomorrow and do a compression test.

 

[joejffrs]

Please explain how you winterized your motor

I'm in San Diego so I drain all water from the engine block and leave hoses off. Boat is fully covered during off season. I change the oil starting the new season. I now remember the boat being tossed onto the shore at the river last time out when a wake boat went by a couple times. Read on a post that water can enter the head if the baffle valves are not good after a good wave hits it. The baffle valves have never been replaced and are probably not there anymore.

 

[alldodge]

The pink antifreeze I mentioned is the RV stuff, but since your in San Diego there is next to no chance for freezing temps. Just weird for thick gray oil, water wouldn't do that

 

[Scott Danforth]

A bad riser to manifold gasket would leak into the cylinders.

When was the last time the risers and manifolds were removed and inspected?

 

[Silvertip]

Again -- change oil and run the engine briefly at the END of the season -- not the beginning.

 

[joejffrs]

A bad riser to manifold gasket would leak into the cylinders.

When was the last time the risers and manifolds were removed and inspected?

They never have been removed Scott.Just drained every year.

 

[joejffrs]

Again -- change oil and run the engine briefly at the END of the season -- not the beginning.

I can see that. The boat does get run in the winter so there is not a extremely long winterization period. I change oil and filter before our annual trip to the river this time of year.

 

[Scott Danforth]

They never have been removed Scott.Just drained every year.

I suggest you pull them, inspect them (acetone test, material tgickness, etc. If you boat in salt water, they only last 5-10 years max

 

[joejffrs]

I suggest you pull them, inspect them (acetone test, material tgickness, etc. If you boat in salt water, they only last 5-10 years max

Thanks Scott-that's what i'll do first. The boat does get into salt water about once or twice a year. When I bought it new at a dealership here, I was told to be sure and drain the exhaust manifolds after every use, which I did. I guess I can't complain about 22 years with absolutely now problems.

 

[Rick Stephens]

Have to repeat what AllDodge suggested. Don't pul heads off the motor until you do pressure tests. Once you pull the heads off you will only be able to wonder if the block is cracked until it is assembled again. I did that, went through magna fluxing and everything, rebuilt the motor and just hoped we didn't miss a crack. Test first, then inspect exhaust manifolds. That way you'll know if there is a leak in the block before proceeding.

 

[joejffrs]

Thanks Scott-that's what i'll do first. The boat does get into salt water about once or twice a year. When I bought it new at a dealership here, I was told to be sure and drain the exhaust manifolds after every use, which I did. I guess I can't complain about 22 years with absolutely now problems.

Pulled spark plugs, manifold risers and exhaust manifolds. #1 cylinder had a lot of rust powder in the exhaust manifold and head and the spark plug was a little rusty. #3 cylinder had a little less rust in the head and exhaust manifold. Starboard exhaust manifold looks good-no rust. Looking around for a set of risers and exhaust manifolds now. Thanks for all the help