Seacast time! (Was: Water in the bilge...got suggestions?)

[danond]

So far I've:

- determined I can hold pressure forever in the cooling system
- determined the leak isn't coming from the engine
- replaced bellows, gimbal, u-joints, o-rings on the driveshaft, shift cable bellows, seal on the exhaust. (Bought a "transom service kit" from e-bay.)
- replaced my transom plug
- confirmed the leak continues with the engine off
- confirmed it doesn't leak faster (actually slower) when moving
- confirmed it leaks even in dead calm water
- inspected the hull exterior for cracks and found only stress cracks around where the gimbal housing mounts to the transom
- confirmed the water is clear (no oil in it)
- confirmed the original bellows weren't contributing (grease in them was clean and water-free)

The leak isn't terribly fast (not necessarily slow, either), I get about a gallon per hour when it's sitting in the lake. I can't see where the water's coming in, just that it's coming in somewhere.

Any suggestions for a next step?

 

[muc]

Re: Water in the bilge...got suggestions?

Re: Water in the bilge...got suggestions?

Check the hose that the lower shift cable runs inside of ---- they like to wear thru by the Y pipe.
Good Luck Muc

 

[Don S]

Re: Water in the bilge...got suggestions?

Re: Water in the bilge...got suggestions?

Doesn't have to have anything to do with the engine or transom shield. Could be the garboard drain plug fitting leaking, trim tab mouning screws. Thru hull fittings for pumps, heads, transducers, speedometers, any screw in the transome or hull below the water line that is not sealed properly, you name it.
You have to find it to fix it.
Many times I have pulled the engine, put the outdrive back on. Blocked off the Y pipe openings and backed the boat in the water and sat where the engine belongs until I find the leak.

 

[ne7800]

Re: Water in the bilge...got suggestions?

Re: Water in the bilge...got suggestions?

I had a simmiler problem on my boat and found it to be the gasket on the outdrive where the hydrolic lines for the trim went in. A good way to test it is take a garden hose and fill the bildge up to the bottom of the oil pan with the nose of the boat as high as you can get it then look at the rear for water comming out and that would be where it is comming in.

 

[hondon]

Re: Water in the bilge...got suggestions?

Re: Water in the bilge...got suggestions?

Here's a fun one that is more prevelent in Mercruiser products.At the top of that y pipe you have an exhaust shutter and sometimes they break free and lodge themselves in the bottom of that y pipe.After time that little pin that was supposed to hold that shutter in place wears a hole in that y pipe so when you are running the exhaust pressure pushes everything out but when static you have that little hole leaking.Sometimes you can hear it but usually not,gotta get back there and look.Just another little tidbit that I've seen.

 

[chiefalen]

Re: Water in the bilge...got suggestions?

Re: Water in the bilge...got suggestions?

Speedo hose wheres that come thru the transom? It have a small leak? Mercs come thru the drive but ive seen a small nick on some. Leak don't even have to be in the back could be in the front and collecting in the bilge. Rub rail, bow eye. Any hole in the tub and not sealed right could do it.

 

[danond]

Re: Water in the bilge...got suggestions?

Re: Water in the bilge...got suggestions?

Thanks guys. I did have a flapper in the exhaust pipe when the bellows and such were repaired. The previous owner installed a custom speedo, I wonder if he sealed it properly.

I'll be checking this stuff out this week and will let you know what I find!

 

[Don S]

Re: Water in the bilge...got suggestions?

Re: Water in the bilge...got suggestions?

Make sure the hose that attaches to the transom shield and has the shift cable going thru it, is tied up high (above the waterline), not laying in the bilge. It's below the water line, and does not seal water tight around the cable.

 

[danond]

Re: Water in the bilge...got suggestions?

Re: Water in the bilge...got suggestions?

I tilted it up as far as I could today and filled the bilge with water, up to about the oil pan. I went outside and found water dribbling down from the bottom of the outer gimbal bearing housing thing, the thing that mounts to the transom and says OMC at the top. Whatever it's called. The water was coming from between it and the transom, looked to be right behind the anode. I didn't see any coming from around the sides and none was coming from the exhaust bellows.

My shift cable is tied up nice and high.

Inside the water was barely over the top of the Y pipe where it comes together.

Looks like it's easiest to get at with the engine out, that's for sure, unless that gimbal housing thing is removable with the engine in, but that looks like severe punishment.

Thoughts on what it might be? Anything typical?

Edit: Oh I was gonna ask, too - if it's the seal between the housing thinger and the transom can I silicone around it for the season? I'd rather not pull the engine during the 3.5 precious months of boating season we have in ND. Hell I'd rather have 3 bilge pumps plus a manual one than burn a weekend if I can gimp by with a kludge for a few outings.

 

[chiefalen]

Re: Water in the bilge...got suggestions?

Re: Water in the bilge...got suggestions?

You put the boat on a trailer after every use? If yes probably get away with it till the winter. You can try putting some marine silacone I know I spell like chit.

Don't let it go beyond this summer.

good luck

 

[Don S]

Re: Water in the bilge...got suggestions?

Re: Water in the bilge...got suggestions?

When the leak at the transom seal where the gimbal housing seals against the transom, it's usually because the transom is rotten (Soft) thus the bolts are loose because the wood went away.
If you run the drive aground or hit it on anything it could pull the gimbal housing further from the transom and you could have a REAL leak that a bilge pump can't keep up with.

 

[danond]

Re: Water in the bilge...got suggestions?

Re: Water in the bilge...got suggestions?

Ok. Boy I'd be surprised if the transom was rotten, this boat's never been left outside in the rain, floor is solid as a rock, always put back on the trailer after use. That'd be a real bummer. I had two engine mount bolts that had backed out on their own, I wonder if I might just have a loose nut or two.

I'll see if I can get to the bolts on the housing and see if they're loose and will also see if I can inspect the wood around the transom opening from the inside.

Last issue I had I thought my block was cracked, turned out to be a missing exhaust flapper and the need for a third oil change.

Thanks for the advice. Crossing my fingers! I'll keep you posted.

 

[danond]

Re: Water in the bilge...got suggestions?

Re: Water in the bilge...got suggestions?

Quick update - I shoved, stood on, lifted, etc. the outdrive today, zero movement at the transom. There's no gap between the gimbal housing and the transom. If the transom is rotten, it's not the whole thing.

Lots of tornadic whatnot happening outside at the moment, I've decided further debugging can wait

 

[Fishermark]

Re: Water in the bilge...got suggestions?

Re: Water in the bilge...got suggestions?

With all the pulling, hoving, lifting, etc..... did you knock on the transom? You can tell from the sound if there is rot present or not. The sloid parts will sound much different that the rotten parts.

 

[danond]

Re: Water in the bilge...got suggestions?

Re: Water in the bilge...got suggestions?

Hi guys. Found what it is - all the bolts that hold the gimbal housing to the transom are loose. My transom is solid, I tested it in numerous places, knocked on it, picked at it, tapped it with a hammer, tried to stick a screwdriver into the wood (I couldn't, it would barely scratch it) etc. Everywhere I knocked it sounded like I was tapping concrete.

It appears it was off once before or it's just loosened up as the paint around it on the inside isn't lined up with the outline of the bracket, and a few of the bolts were only a bit more than finger tight. I actually got 4 or 5 turns out of one of them.

Looks like I'll be yanking the motor to get at the ones on the bottom to tighten them up. That'll be a good time to clean and paint the bilge, put in a second pump and replace the flapper(s) I know I'm missing.

It seems weird that they'd get loose on their own, so I'm not ruling out rot, but at this point it doesn't matter, engine has to come out so I'll be able to confirm it once I'm in there.

GEEZUS. Maybe once I'm done I'll get a peaceful weekend on the water. Yeah that's right, I plan to put my boat on the WATER, not just fix it on land!

 

[newboater2day]

Re: Water in the bilge...got suggestions?

Re: Water in the bilge...got suggestions?

well i had the same problem on my searay was leaking water slowly into bilge i checked everything could not find the leak so i bought some black silicone and went on the outside of lower unit where it mounted on the transome and sealed it all the way around and that stoped my leak something you can try

 

[danond]

Re: Water in the bilge...got suggestions?

Re: Water in the bilge...got suggestions?

Yeah I thought about that. I was able to get at 4 of the 8 bolts holding it on, so gooping it up might work through the season, but honestly if I can figure out how to hoist the engine out and over the side of the boat, I can't imagine the whole operation taking longer than a day.

 

[danond]

Re: Water in the bilge...got suggestions?

Re: Water in the bilge...got suggestions?

Well I dunked it in the water today after tightening the bolts I could get to on the transom bracket. No difference whatsoever, but I did find that it doesn't leak until I get water above where the shift cable goes through the transom. That seemed to indicate I have a leak at the exhaust or a leak in the shift cable hose. I'm going to hit the area where the shift cable goes through with a stream of water tomorrow and see if it goes through.

Ugh. Regardless, this makes me tired. Going to pull the engine, this fiddling is wasting time and no matter what I find it looks like an engine pull to fix it anyway. SUCKS!!

 

[danond]

Updated: Water in the bilge...got suggestions?

Updated: Water in the bilge...got suggestions?

Well the engine's out, that wasn't so bad. Took an afternoon and a very tall A frame lift but it's out in one piece with no damage.

Lots of good news, the lag bolts came out dry, the coupler looks good, I found the remains of my other flapper, the transom and stringers appear to be quite solid.

We re-installed the drive and took it to the water, dunked it and as Don mentioned, we sat in the engine compartment and waited for the water to start coming in. I was able to see it pretty clearly pooling in a small cavity under where the Y pipe bolts to the gimbal housing. It doesn't appear to be coming from the exhaust pipe, but rather it's just "filling". It's really looking like the gimbal housing seal has failed, was improperly installed, or *something*. I dunno at this point.

So in looking at the manual it's not readily clear how to get the gimbal housing off. It walks through removing *everything* but is this necessary? Do I have to remove the pivot housing, gimbal ring, etc, or can I disconnect the hydraulic lines, disconnect the steering, unbolt the transom plate and take it off with all the other stuff still connected?

 

[danond]

Re: Updated: Water in the bilge...got suggestions?

Re: Updated: Water in the bilge...got suggestions?

*bump*. Any words of wisdom on the transom bracket/gimbal housing removal question?