HELP! 2004 2575 RFS Takes on water in Engine Compartment!?!?!? HELP!

cathole

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I've got a 2575 RFS 6.2L 320HP i/o Mercruiser with Bravo III drive Tri-Toon and everytime I pull a tuber or make sharp turns, the engine compartment fills with water.  I have had a qualified mechanic check every possible thing he could think of with no obvious problems found.  He checked the bellows and even filled the compartment with water while on the trailer.  He couldn't find a leak.  I noticed while tubing that there is a tremendous amount of water flowing between the tritoons while moving.  I also noticed  small openings in the aluminum shield directly below the marine plywood deck that runs between the toons toward the front of the engine compartment.  These openings might be approx 3/8"x3".  Are they responsible for all the water entering the engine compartment?  I'm not even certain water would enter the compartment through these openings.  The water entering is enough to make the bilge pump to run constantly while pulling tubers.  the engine also loses power it seems and sounds bad when the compartment fills with water.  Why is this?  is it due to the bateries getting wet?  What can I do to resolve this problem?  Keep in mind, this problem never arises untill I make sharp turns.  I'm feeling helpless and I desperately want to fix the problem and go tubing more!  
 
Geez, where to start.... First, sorry to hear you are taking on water, and after thinking about it for a minute, here are a couple of things to try.

1)  Have someone carefully look in the engine compartment while performing some hard turns to locate where the water comes in

     ( this is potentially dangerous, so take my advice with good judgement )

2)   Trailer it to the local car wash, use the high pressure water and spray around all areas while someone looks in the engine comp.

Maybe some others have more suggestions?

Good luck, and keep us posted!
 
Mount a go pro and a light if you have one, or borrow one from a freind.
 
thanks, both very good ideas.  I have tried having a friend watch the compartment while making turns, however, the water that entered wasn't noticebly gushing from any specific place.  I will try both of your ideas by the end of next weekend and report back.  Thank you!  
 
Didn't you have this problem before?!? I guess the ideas/suggestions that I had wasn't the problem or solution...........

I'm w/Geoffrey/Brenda........only way you're going to find out is to have somebody observe the engine compartment while you're underway.................
 
is the water coming in over the transom or leaking in somewhere? Isnt the bilge pump supposed to be pumping iy back out?

Camera idea is good one

does the boat plane out under power?
 
Lightly pack some toilet paper in those slits you were mentioning and then go do some turns. If the toilet paper is wet, or preferably missing because it got blasted with water, you found your leak.
 
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Then pack some of that putty you put on your house wherever a pipe comes through (phone, electrical, A/C, sump, radon exhaust, etc) to seal out water, and do some more turns.
 
Awesome suggestions! I'm anxious to try them out. Yes i didnt have any luck last season diagnosing problem. My mechanic also tryed numerous things: checked seals, flooded compartment, etc. He said gimble bearing seal might need replaced before next seaon. The boat planes out very easy but while turning there is a ton of water blasting through between the toons. I have the rough water package that includes the strakes. Not sure if that makes a differece but might kick more water up while cutting turns. I am hopefull the two small openings are problem. It seems like the path the water is taking is high due to the fact the compartment doesnt leak when on trailer and filled with water. Thanks for all your help guys. I will try garden hose first through the openings. Then i will try the toilet paper idea. I am sure the paper will get wet, so i will be filming the inside compartment as well with my waterproof lumix. I'll let y'all know!
 
If you're sure the toilet paper will get wet, skip that step and just use a rag. Jamb it in the crack with a screwdriver. Then do some turns. If that seals it, pull the rag and fill the crack with some duct seal putty. Or caulk it shut with silicone if you can get the tip of a caulk gun up in there. Good luck!
 
The duct seal stuff is water proof while staying pliable, in case you want to remove it. Use your best judgement on what to use.
 
00001.jpg

I finally found where the water is entering.  Here is a video: 

http://youtu.be/z-UQH9Y-tUk

Also there is an access hole cut in the shield for the fuel tank that allows water to enter.

00001.jpg

I will be siliconing the channels along the top sides of the compartment along with a cover on the top of the fuel tank shield.  Hopefully this will solve the problem. 
 
Great news!
 
Are you SURE that's where the water is coming in??? 

Ha ha.  It's POURING in by the bucket!!!

I'm sure you know, but make sure you either caulk it from the outside, or if you can't get up in there from under the boat, press the caulk well through the crack with your finger so it mushrooms out the other side.  Over time, the caulk will be less likely to push back into your engine compartment that way.

Thanks for posting.   I was curious what the deal was.
 
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^_^  I thought that might make for an entertaining video!

I'll be sure to press it through, thanks for the tip.  I can't access the outside because there is aluminum riveted between the toons under the plywood deck and framework... Which is one of the baffling things about the water.  By the looks of the underside, I wouldn't think that much water would be finding its way in.  
 
Perhaps where it's coming in isn't where you should seal it then... just a thought...if it doesn't come in there, where's it gonna go?

On second thought, not all of it would be coming in anyway, so what doesnt come in has to be going out somewhere.

Maybe investigate some more, but you have to keep it outfof the engine compartment, so just seal it off.
 
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That's a sh**load of water coming in. Have you checked the nuts and bolts holding the motor pod to ensure they are tight?

With that much water, if it were me, I'd say screw it, and pull the wave shield off, and seal it from the best side (outside).

That's a lot of water pressure, and I'd bet you can't get enough in there from the inside that it won't push out. I could be wrong, but the pressure of that water might be deceiving. I still can't believe that much is coming in !!!
 
A loose motor pod is a good thought.  Grab any part of it that you can grab onto and shake it as hard as you can.  You might have to use a strong light and mirror, but compare the side that the water is coming in with the other side of the boat.  If the crack/opening is non-existent on the good side, then you know that's the problem.  If there's an opening on both sides, then you know the problem is somewhere "upstream", and sealing it is just treating a symptom instead of curing the problem.
 
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Another item you could TRY on the INSIDE after cleaning it well is Dupot Tyvek Flashing Tape or any other HIGH QUALITY EPDM Rubber flashing tape. Make sure it's the one sided and HIGH QUALITY. Don't buy cheap sh** or it won't stay stuck. We sell a brand at work (forget the name) but it's two sided sticky for rubber to rubber repair. You need the one sided ..... And the stuff we have is nasty to get off once stuck. I'll try to remember to post the name tomorrow. I would bet Derricks paycheck, it will seal this from the inside if installed properly.
 
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