3.0 alpha one water leak only when running

[Rmcduffie49]

I've tried but to be honest from what I can see it's coming from the area of that lower vent hole under the spinning driveshaft (only leaks when running). So it's either that lower vent hole or the top of the exhaust tube where it makes the u at the top. With that being said its just odd to me that with both of those being the area it's coming from why it wouldn't leak at all with the motor not running. It's a steady stream like barely turning on a faucet when the motor is running and absolutely nothing when the motor is off. I would also think that if it was coming from behind the motor it would be splashed by the driveshaft somewhat or dripping some before it gets to the back of the shaft and it's not at all. Bone dry above the spinning shaft.

 

[Rick Stephens]

A couple things are happening different when running:

The water pump in the leg is pushing water through the input line which passes through the transom right above the drive shaft.

Water is being forced out the exhaust. When on muffs there is zero back pressure to the exhaust system. When in the water there is back pressure that the exhaust and exiting cooling water has to over come. I had a loose clamp on an exhaust at the top of the Y pipe, it would only leak when in the water with back pressure.

There is also any component that is under water level. If it isn't sealed, it can leak directly into your boat.

 

[Rmcduffie49]

Alright so got the boat to the house, hooked it up to water and she still leaks when running. I proceed to look around with a mirror and water still appears to originate from right above j pipe connection to the gimbal housing. I also find a bad pinched frayed trim sender line but that's another story. So I pull the drive off and I find that there is a slight amount of water in the drive shaft bellows. However all bellows look great with no holes. The oring for the water inlet was distorted though which I believe is my culprit. My question now is with the drive off can I simply put a garden hose up to the water inlet hole on bellhousing to make sure the exhaust tube isn't leaking.

 

[Rmcduffie49]

So ran the boat with a garden hose pushed into the water inlet on the bell housing, and no water leaks even with boat running, I find it so hard to believe that oring around the inlet was the culprit but I guess it was letting water run through the u joint bellows and into the bilge only when the motor was running. At least I'm not pulling a motor to fix a j pipe like I originally thought!

 

[Bt Doctur]

like I posted, there really arent too many places water enters. leaky bellows, leaky inlet O ring, missing rubber ring, or torn mounting gasket.
Now another strange leak is water flowing out of the shift cable with the motor running.Thats the damaged O ring and mounting gasket. It allows water to enter the shift cable area and into the shift cable.

 

[Rmcduffie49]

Funny you mentioned that there was a very slow drip from the shift cable assembly, dang oring! Wish the trim sender wires weren't frayed or I would get by with a quick fix. Going to go ahead and do a bellows kit and a gimbal bearing since they are though.

 

[Rick Stephens]

Dead giveaway when there is water dripping from the engine end of the lower shift cable. Inlet o-ring.

If the lower shift cable is still in good shape, pull the cable out of the lower cable housing and use electrical contact cleaner to spray the water out of the housing, then shoot air to completely dry it out. No Lube! Reassemble dry.