AQ125A excessive steam coming from crankcase

[Andyschwarz]

I noticed yesterday that I've got a lot of steam coming out of the crankcase vent line that ties into to side of my carburetor. It appears that there is water getting into the crankcase. The steam appears to be clean and does not smell like antifreeze. Is it possible that im gyetting seawater backing up into my exhaust valves from the exhaust manifold? I also have a leak that won't stop on the cleanout strainer cap on the seawater heat exchanger. The engine runs good and is not running hot. Do I have a head gasket problem or a heat exchanger problem?

 

[boatdoc55]

Are you sure it's not just normal blow-by? What does the underside of the oil fill cap look like?

 

[pugetsounder]

Could be two seperate issues. Your exhaust manifold could be clogged up causing excess pressure at the seawater strainer. The other could be excess condensation in the motor over the winter. Drain the oil, fill it back up, run it with some oil cleaner, drain it again and then change the filter and oil and see what happens after that. If you still get water in the oil then on to step two.

I've been through both issues in the past year.

 

[el_pescador]

If you have a leak in the seawater strainer, I would not be surprised if the lip is cracked (it's plastic), in which case you will have to replace the strainer. That's a pretty common problem. But if the gasket under the cap looks iffy, try turning it upside down (that little trick works sometimes if you haven't already done that).

Sometimes a faulty head gasket could cause the steam problem you are experiencing, but in that case the oil would look milky. If the oil looks fine, then what you are seeing is probably blow-by gas.

 

[Andyschwarz]

I removed the dipstick after letting the boat set level overnight. No signs of water or milky looking oil, and the oil level was nearly to the full mark. I also removed the drain plug and drained about a 1/2 cup of oil. No signs of water or milky oil. Also checked the antifreeze level, full. I'm going to drain and replace the oil and filter as mentiond above and see what happens. If the problem returns I will pull the exhaust manifold and check for blockage. I picked up a complete aq125a spare engine, out of a newer freshwater 18.5 foot bayliner capri, for next to nothing, so I can swap out parts as needed....I'm going to switch out the seawater strainer cap tomorrow and see if that leak goes away. Thanks for all the comments above..I'm new to this forum and really enjoy reading all the other topics on the old VP engines. I'll post updates as I figure this one out!!!!! Andyschwarz.