Over heated exhuast manifold makes for a bad memorial day

[myersmafb]

Today while heading out to a fishing spot on the bay my wife informs me of a burning smell, so i stop the boat and sure enough smoke is coming from the engine bay. I opened it up and the starboard side exhuast manifold is scorching hot while the port side is warm. The day out fishing was over before it started but luckily a fellow boater was kind enough to tow me in. After getting it home I started it back up (which i now realize was a poor choice becuase it was hydrolocked). The motor did start but was very rough. After realizing i just managed to start an hydrolocked motor i shut it down pulled the plugs to drain the water and checked the compression on the cylinders on that side which calmed me a little after they all checked good.

I found the water blockage in the thrermostat housing blocking probably 80% of the flow to the starboard side manifold. It was a small peice of the impeller wedged in there. So that should clear up why the side overheated.

My question is how did the water get into the cylinders?

I realize the manifolds and risers comonly fail especialy if used in salt water. Although i'm not sure how they fail. (crack, or clogging from corrosion or debris is the only thing i could think of). So i pulled them off and yes there was some buildup and corrosion but nothing to impede the flow and no cracks or leaks. The gaskets seemed to be in fair condition as well.

With the water blockage fixed i would like to replace the gaskets and try it out but i want to be sure that i dont put my engine at risk by hyrdolocking it again so im looking for any ideas as to how the water got into the cylinders.

thanks for any and all help in advance

Engine is a 2000 5.0 GI PEFS

 

[Justin Kennedy]

Re: Over heated exhuast manifold makes for a bad memorial day

Inside the manifolds the water passages get corroded to the point where they leak into the exhaust passages, you can't see the holes because they can be pin sized or just deep inside where they are not visible. Once they get hot and the water pressure increases, they leak. If you haven't replaced them in a few years and your in salt water, i'd say replace them sooner rather than later.

 

[myersmafb]

Re: Over heated exhuast manifold makes for a bad memorial day

Thanks for the reply, I was probably going to replace the manifolds and risers anyways. Is there any third party manufactures becuase to get them from VP will put me back about $1200. a little more than i want to spend every few years for new manifolds. Also is there any places anyone can recomend shoping for VP parts. And my final question is there anything else i should do since i found water in the cylinders.

thanks in advance

 

[Bondo]

Re: Over heated exhuast manifold makes for a bad memorial day

And my final question is there anything else i should do since i found water in the cylinders.

Ayuh,... Is it Saltwater,..??

It might be too late, but ya Gotta get it Runnin' to oil it up, 'n Blow the saltwater out...

 

[myersmafb]

Re: Over heated exhuast manifold makes for a bad memorial day

I ran it right away after i pulled the plugs to drain the water. my concern is more the heads and the engine oil. i drained the oil becuase it was milky and replaced it with fresh oil but the oil i see running through the head is still milky. will this hurt the engine? should i have to drain and refill the oil more than once?

thanks

 

[Bondo]

Re: Over heated exhuast manifold makes for a bad memorial day

I ran it right away after i pulled the plugs to drain the water. my concern is more the heads and the engine oil.

Ayuh,... Yer probably all right...
The snot in the valve covers is condensation that'll steam off when ya run it good, 'n hard...

 

[Justin Kennedy]

Re: Over heated exhuast manifold makes for a bad memorial day

Lots of aftermarket available, just make sure the fit together well, check them with a straight edge first, file them flat if you need too. I used GLM on mine and they have been pretty good.