Crankcase vapors???

[ckraker]

1989 4.3 mercruiser just rebuilt. Finally got to fire it up for the first time today. It sounds great! About 5-10 minutes after startup(operating temp) i noticed vapor coming out of my crankcase breather tube. I understand that's normal, but it appeared to be more of a water vapor than an oil. Smelled watery too. That and the fact that it only showed up after i was hot makes me think i got water getting in somewhere.... Maybe I'm just nervous but this engine didn't need an overhaul for no reason.... It's had some issues and I'm wondering if a small water leak might be part of the problem... Thoughts?
Thanks

I ran it for another few minutes and can see what appears to be water droplets on the end of the breather tube. Where is it coming from? So bummed

 

[ckraker]

I pulled the exhaust riser elbows. The gaskets fell to pieces.... Not sure if they were leaking or not. If they were, can someone explain to me how water in an exhaust manifold can turn into water vapor in my valve covers? I'm hoping for a simple solution, and this might be it. The heads and block were just checked for leaks so I'm assuming that it isn't a major problem like cracks.

 

[alldodge]

Exhaust maybe, but would also think of intake
Check your oil level

 

[ckraker]

Brand new intake, i hope that it's not leaking already. Just checked oil. It's milky and slightly overfull. I couldn't be more disappointed. Could this be from the riser gaskets? Or is that wishful thinking?

 

[Rick Stephens]

What was the history requiring a rebuild? With a V6, the most common crack location, if that is a possibility, is the lifter valley just above the lifters. Other than a head gasket or a cracked head, not many other places to get water in the oil just from running on muffs. I would not expect to get water in the oil from that situation from an exhaust problem unless you had shutdown and the manifold filled up with water...

 

[ckraker]

Last year it overheated and dropped a valve seat. The machine shop magnafluxed everything. No cracks in head or block.
I just pulled the intake manifold and didn't see any obvious flaws.
Must be a significant amount of water in the oil already.... It's very milky.
I was hoping my riser gaskets were the issue because they looked like junk... But i can't imagine how water would get into the engine from there....i had no hydro lock issues upon several starts.
I don't currently have my outdrive on. I'm running with a hose going into where the outdrive would pump it. So it could have been putting water into the exhaust even with the engine off.... But like i said no hydro lock symptoms.

 

[alldodge]

New intake, but if gasket did not seal at crossover port, it would leak.
It should just spit balling

 

[alldodge]

Pressure test the cooling system
Plug hoses going to exhaust
Remove hose coming from drive the thermostat housing
Connect gauge to thermostat housing where hose was and pressurize to 15psi and listen