So, since I'm the best at this stuff, my family has elected me to try to fix my brother's boat.

After winterizing mine, and my 2 ski's... i had the fun of doing his. (ohh and my dad's twin engine, so I did 6 engines last fall!)

When I drained the oil (we attached an extension to the plug) ran it out the drain plug from the boat.

First 1/8th of a a gallon was... water. This was after running it approx 5 miles where it would make a grinding noise over 3k (but that sounded more like the lower unit)

Also it would shut off when going from plane to idle (I think my dad's mechanic 'improved' it by taking it to a 400 RPM idle vs the original 600). It will idle at 400, but only warm (it's got carbs) and only if you baby it in / out of gear. and you better get in gear and on the throttle fast, else it stalls.


OK, so problem 1, water in the oil. Engine is a 1 year old 5.0V8 double barrel carbs, open cooling system. installed last spring.

Where do I start?!

First I planned on running it on land (with ear muffs/ hose) to see if the oil becomes watery again (do I have a choice?)

Then if it does, what do I take apart next?

I know you can check a cars cooling system for leaks w/a radiator pressure test? can I check a boats?

Thanks! Photos / more coming soon as I get the boat moved to my house...

how can I upload a photo here?

All of the"freezers" that people have brought to me and that I've
replaced engines on have had GALLONS of water in the oil pan, not just a pint.


You can pressurize the engine, it just takes a little
creative plumbing.

Block off whatever comes out of the thermostat housing,
and pressurize at the engine recirculating pump inlet.

You have to be a paying member to post pic's.

First, pull the exhaust risers/manifolds and look inside. If they are cast iron and never replaced, I'd start there. Also, pull the plugs. You will see signs of water or rust in the manifold as well as the plugs if the manifolds are leaking. When manifolds rust out, it's usually pretty obvious.

my other friend suggested I run compression tests on all 8 cylinders... I have the tool, so that should also tell me if it's working remotely right.

My brother's last engine.. a 4.0L in his jeep was eating coolant for years (head gasket most likely) but the stupid shops never replaced it... even though I had all the tools to do it.

He overheated it, and one piston had a hole in it, the other was cracked in 1/2...

thanks! I will report back when I get to work on it...