5.7 MPI Bravo 3 leaking into the bilge

[Ignatios]

Hello Gents,

I need your thoughts and experience if you don't mind.

My boat when it is standing still in the slip, it is bone dry, BUT when I start it i get a steady stream on water that would trigger the bilge pump in about 2 hours. then I vacuum it and it will be fine, no leak.
Now I checked thoroughly all the hoses no leak the leak was coming from the bottom of the plate the lowest part of that plate behind the engine.

where do you think it is coming from or did you have any similar experience.

Thank you very much

Nick

 

[tpenfield]

"the leak was coming from the bottom of the plate the lowest part of that plate behind the engine."


Nick

I don't know what that means . . .

Is the leak coming from the engine block (somewhere) or the transom assembly?

 

[alldodge]

It will be hard to see but check the exhaust Y pipe area, or raw water pump

 

[Bt Doctur]

If between the rear mount and the engine could be core plug freeze damage

 

[Ignatios]

TPenfield

It is from the bottom of the transom plate

 

[Ignatios]

All dodge

Nothing leaking from the transom to the front of the engine especially the water pump at the front of the engine, no lack there.

 

[Ignatios]

But doctur

It is coming from inside the transom plate nothi g is leaking from the between the plate and the front of the engine

 

[Ignatios]

Gents,

Would the Y pipe leak only when it is running?
how about the pickup hose what's it like at the plate where it gets connected?

 

[alldodge]

Would the Y pipe leak only when it is running?

Yes if there is a hole/crack above the water line or if the exhaust boot has a leak

how about the pickup hose what's it like at the plate where it gets connected?

not likely to leak there because when more is running that is on the suction side of the pump

Bt may have the right answer if its not the transom.
Take your phone and film under and around while running

 

[Ignatios]

I'm thinking about disconnecting the y pipe and stick a garden hose in there without turning the engine on ofcourse and see what I get...any remarks on this idea?

 

[alldodge]

Won't hurt a thing and will let you rule it out

 

[Ignatios]

Ok the latest and the greatest...
I started the other engine (starboard engine) only and behold the port drive started to leak I shut it off it stopped leaking!!!
So I went back and played back and forth with that to zero in on the problem, the results are the following transom leaks from the top by the swivel pin when I see water there so is at the bottom the opposite is true.
now if I turned my steering ad if I'm heading to the right no leak doesn't matter engines running or not if I turn the steering to the left the port side starts leaking...
Now note the top of the drive is very close to the water water line, what are your thoughts?

 

[alldodge]

Your steering pin is leaking or the transom

 

[Ignatios]

Alldodge, Why you say the transom?

 

[Bondo]

Alldodge, Why you say the transom?

Ayuh,...... Because transoms have been known to rot out, 'n you don't mention the vintage of the hull,......

 

[Ignatios]

Bondo,

Its 2000, but I don't think that vintage necessitate the transom to be rotten otherwise everybody would change their transom at certain age.

I was looking for a technical reason or explanation...to me and I don't have lots of experience on boating mechanics but if the transom is rotten it should leak at all times it is an open hole shouldn't be effected by weather the steering wheel is turned left or right...but if it is so please explain it to me...this is what I'm here for to learn from The other's experience.

Thank you

 

[tank1949]

But doctur

It is coming from inside the transom plate nothi g is leaking from the between the plate and the front of the engine

Dry or wet slip??? You need to get a slender friend, mirror or remote camera and view that area and on both sides and pray it is a loose hose, but I am afraid that you will find out what so many of us have dreaded: rotten transom. If a salt water boat, then possibly a corroded y pipe and gimbal plate/housing as well. It could also be a bellows is leaking or cracked. Is your rubber original? 20 years is a long time. But before removing motor in order to replace y-pipe and transom please make sure it is not something else!!!!! Your looking at 5-10 K expenses, unless you do it yourself. Good luck!

 

[Ignatios]

Tank1949,
all bellows are under 2 years old, ransom was checked to be ok unless it is something hidden...the thing that I don't understand is what could it be if when turning the steering to the right now no leak for 2 days, bone dry, and it is sitting in a slip but if I turn the steering to the left it start dripping that in about 2 days would trigger the bilge pump. Shouldn't a rotten transom be leaking at all times? Regardless? Or there could be a case where this can happen.

 

[tpenfield]

My boat when it is standing still in the slip, it is bone dry, BUT when I start it i get a steady stream of water that would trigger the bilge pump in about 2 hours.

Just to re-visit . . . The leak only happens when the engine is running (right?) So, it rules out a bunch of transom related stuff.

Bravo 3 'sucks' the water up to the engine (sea water pump) and then 'pushes' the water into the engine. Sooo, I'm thinking from the sea water pump exit side all the way to the exhaust elbow rubber fittings is where I'd be looking. There is a bunch of stuff in between those two points in all areas of the engine.

Often, the only way to find a leak is with the first hand set of eyes. You are going to have to run the engine and look, and keep looking until you find it. A mechanics mirror can help in this regard.

 

[tank1949]

Tank1949,
all bellows are under 2 years old, ransom was checked to be ok unless it is something hidden...the thing that I don't understand is what could it be if when turning the steering to the right now no leak for 2 days, bone dry, and it is sitting in a slip but if I turn the steering to the left it start dripping that in about 2 days would trigger the bilge pump. Shouldn't a rotten transom be leaking at all times? Regardless? Or there could be a case where this can happen.

I paid a marine surveyor who incompetently gave my boat a good bill of health. My current boat's transom didn't leak at sea trial. Boat had been stored dry on lift for a couple of months prior to ST. It didn't start leaking until after transom cavity or rotten void filled with water (best guess) later on while we were testing autopilot at sea. Apparently, the surveyor didn't pound hull and listen for sound differences. Go buy a mirror on a stick! You will find the leak. Good luck!