oil appears milky brown

[seanrossetter]

i bought a boat with a mercruiser 228 last fall and had it out a few times with no issues. the guy i bought the boat from said to just unscrew a couple of drain plugs to winterize, that's what he did with no problems. i was able to start the engine, but after running for a few minutes, the engine started sounding rough and light brown fluid came out and covered the top of the engine. it appeared that the fluid came from the flame arrestor, but that just didn't make sense to me. (these hoses are loose and i will replace them regardless, is this normal?) i pulled the dip stick and it is covered in the same... i obviously don't know the first thing about how these engines work, so any clues as to why the oil would be this color and why it would come out the top of the engine would be greatly appreciated. my first thought is that the block is cracked and water is in places it shouldn't be

 

[saywhat]

Re: oil appears milky brown

Take a look at this....

http://forums.iboats.com/showthread.php?t=369864

 

[seanrossetter]

Re: oil appears milky brown

thanks. expected this kind of reply, but was hoping for something different!

 

[04fxdwgi]

Re: oil appears milky brown

Sounds like you are pumping water into her at a pretty good rate and would indicate a cracked block / head / intake manifold due to improper winterizing / draining. "Brown Fluid from flame arrestor" was probably oil coming up the valve cover vent line hose attached to the arrestor and spilling all over the place at the carb, since the rest of the engine is basically sealed and that's the only place for it to escape. If the PO only pulled drain plugs from exhaust manifolds, then the engine was still full of water during the cold months and he (you) did indeed crack a major component and turned the engine into a fancy door stop or yard planter.

If the engine is raw water cooled, then there are no less than 6 (yours may be different) places to drain water (on a V6 or V8) from when draining the engine.

The basic places for a V6 / V8 are:
1. Bottom of each exhaust manifold.
2. 2 engine block drains. One on each side of the block at the lowest point.
3. Drain on each and every heat exchanger / power steering cooler / oil cooler
4. Remove hoses to raw water pump (if equipped w/ an engine driven raw water pump) and spin engine a few revs (don't start) to purge water from pump body.
5. Remove lower hose from regular engine water circulating pump to drain.
6. Pull plug from thermostat housing.

I know that's not what you wanted to either, but it is what it is..... I would deffinately be pulling the motor and looking for a replacement. Coming out of the vent tube is NOT a small leak. It's MAJOR.