Leak from somewhere?

[Espos4]

This would involve a little work, but could you swap this manifold over to the other motor?

If so, once you do that, a few runs will tell you if this is a manifold issue or some other external source creating this.

If you are a DIY guy, some gaskets and your time are the only costs.

 

[M Prod]

I’ve decided to replace the manifold. I’m done speculating and figuring out a course of action for possible repairs/fixes. After many observations while running, it appears that there is a problem in the manifold itself. A problem that involves cooling salt water seeping through a porous section of the manifold. A bad casting? Maybe. Still hard to tell. The source is definitely the manifold though. There is no spray down there when running at 3500 rpm ..no visible leaks ..nothing felt or seen anywhere around the manifold when running full cruise at 175 degrees. But yet the salt spots appear somehow. I’ll know more next week when I pull it. My engines are too valuable to risk a potential ticking time bomb manifold.

More to come and more pics.

 

[M Prod]

I finally figured it out. I replaced the manifold today and good thing because the old one was almost eaten through with rust in that area. Inside was fine so no water getting into the engine. Took the boat out for a sea trial ..everything looked and seemed fine so we closed the hatch and motored back to the marina. Popping the hatch at the marina and SHOOT ...there’s salt residue on the new manifold, exact same spot. After swapping some hoses to no avail and then finally putting a bilge diaper over the port shaft seal, I got it. It’s the shaft seal. Strange thing is I can’t see or feel a spray, but that’s definitely it. Maybe it’s spitting intermittently in that direction? Every other time I’ve had the boat out salt residue has appeared on that manifold in that spot. And the only time it didn’t is when I covered up the port shaft seal. And there is a straight very clear shot from that seal right up to that manifold. So there it is. Fortunately I’ve still got spare seals on the shafts so changing during haul out in 2 weeks won’t be an issue. Happy to finally understand what was happening here and almost have it completely solved.