Water in top end of motor

[popeyefoghorn]

A friend has a problem with his boat and is baffled by it, he needs some help so I offered to post it here for him.1996 240 ov SeaRay with a 350 Mercrusier & alpha 1 outdrive. On 2 occasions water has got into the top of the motor making it hydraulic. He pulled the plugs out finding no water in some & alot in others, mainly on one side, there was no water in the oil. The 1st time it happened while idling at the dock. The 2nd time the boat went about 5 miles, idled in neutral for a few minutes, then just before planing out it hydraulic again. Someone suggested the water getting past the flapper in the exhaust. Any thoughts on this would be greatly apprec. Thanks

 

[clanton]

Re: Water in top end of motor

Search member 17040, risers may not be high enough from the water line. You should also call Searay and Mercury.

 

[f_inscreenname]

Re: Water in top end of motor

I really cant see water getting in through the exhaust flapper while underway. Sounds like to me when the motor's exhaust gets hot is when it happens. I would be looking at the exhaust manifold. Cracks in metal will expand when they get hot. I had a cast iron frying pan that got too hot once. With a pop it split down the middle but when it cooled off you couldn't find the crack. After that it worked great for short order stuff but if you left it on to long it would drop anything liquid on the stove. It was a sad day when I had to pitch it. A good seasoned black cast iron frying pan is a hard thing to replace. <br /> Think its time for a pressure test on the manifolds and risers.

 

[taz33911]

Re: Water in top end of motor

I would have the manifold checked first.Calling searay or mercury will probably get you nowhere if the boat was still under warranty maybe searay.If the manifold is not cracked get a riser kit to raise it up 3or 4 inches.Just a little tip make sure to winterize before freezing weather at least make sure to pull all the freeze plugs should be blue and there is one in each manifold one in each side of the block and pull the lower end of the hose on the water pump oh maybe one more if it has a heat exchanger under the motor mount near the oilpan would have a water hose coming in and out it would have a little blue plug under it somewhere also. I have seen what a cracked block on a 454 mag looks like when they forgot to winterize cheaper to pull the plugs.

 

[MrBill]

Re: Water in top end of motor

In the January 3, 2003 issue of BOATUS Magazine a very informative article "Engine Blocks Choke on Water" appeared. For nearly a decade Merc had water ingestion problems in certain engines, usually not severe enough to 'hydraulic' but severe enough to seriously corrode and damage.<br /><br />The article implied that for Mercruiser the problem was concerned with the "big block" (454 cubic inches) but several other problems have been reported and photoed for other engines, particularly the 350 icd.

 

[popeyefoghorn]

Re: Water in top end of motor

Thanks for the input I'll pass this on to him.