Water in the bilge

dgelles

Seeking assistance with possible causes of water in the bilge on a 2011 310 Express with Bravo 3 out drives and Merc 350 Seacore Engines. Both drives have been pulled and all bellows, gimbal bearings gaskets and trim components replaced. The drives have no play and meet factory compression.  The bilge fills up with about 3-4 gals while the boat is docked and currently all seacocks are closed and all systems closed and winterized. The drain plug and drain plug housing is good without water infiltration.  Note this conditions exists in dry weather so no rainfall.  The water level never goes beyond a few inches of the center strake up to the sides just shy of the float kicking on. I have shop vac everything dry as a bone and the next day the same amount of water as indicated is present. I have tried viewing and can’t see anywhere water may be coming in from.  Help is much appreciated, short of purchasing a go pro and leaving it on for 24 hrs in the engine compartment. Note the attached picture shows the water level with oil present. The oil is from the trim reservoir that cracked and leaked which has been replaced prior to the photo. 

Thanks

skennelly

Did you inspect the steering arm area...no signs of water entry there?

LaRea

You've ruled out the freshwater system, rain ingress, systems controlled by a seacocks (genny, AC, raw-water head), drain plugs, bellows ... all the usual suspects.  Done your homework for sure.

Have you tried drying the bilge and scattering powder such as talcum to look for drip trails?  It's cheaper than a GoPro.  

TonyG13

I have the exact same scenario with our 2014 310 EC. Also cannot figure it out and checked everything like @LaRea mentioned. It's usually about 4 gallons, cuz I have a two gallon wet vac and fill twice to empty the bilge.

Can anyone else with a late model 310 chime in? @jbschmalz23 - Josh, what's yours typically look like?

skuter99

I had the same thing. Mine is coming in by the steering arm. Will be fixed in the spring before launch

randy56

Check water heater and hose's mine was just that. The area where the water is heated through engine. 

rasbury

For a boat that is supposed to float there is a ton of places to sink it! Did not here where the speedo tube connects at the transom...are you closed or raw water cooled? Either way get the water flow diagram for your motor and follow the water...you did say your winterized so your air is not running...that will generate a half gallon per hour! Powder around the seacocks as the seal on those will leak for sure...very hard to see just looking...hose clamps will fail- especially if someone cuts a corner on a cheap one. Leaks are tuff!

GMSLITHO

Did you check the mercathode system at the bottom of the transom assembly its almost impossible to see from inside the boat 

rasbury

good call...

dgelles

Thanks to all for your comments, I will look at the steering arm and check the cathode when I pull the boat out of the water. And of course recheck the seacocks and use talcum powder to check.  If anyone else has some suggestion, I’m all open. Again Thanks to all.

skennelly

Check the steering arm from the inside of the engine compartment while in the water.  If it's leaking there you should have a puddle of water where the steering arm connects to the steering pin.  It may also look rusty if the water has been leaking for a while.

J3ff

Have been going through the same thing. 

It came down to pulling the boat, leaving the plug in, filling it with water with the bow high in the air and then pulling on the drive side to side... it only started leaking then. Don't have the official word on what it is yet, but it appears to be some kind of gasket in the transom assembly.