Cracked exhaust manifold?

I recently took off my exhaust manifolds. Manifolds are 26 years old and look to be in terrible shape on the outside. Once they were off I noticed the second cylinder exhaust port on the manifold has signs of rust. I have not noticed milky Oil so I'm a little unsure on what to do from here. I planned on installing new manifolds anyways but I'm not sure if i need to pull the heads?

The only way to know for sure is to pressure test the manifolds.

Good thread on pressure testing.

Brian82683 wrote: I'm curious to know if buying new manifolds would be the fix all, opposed to having to dig deeper and remove the heads as well.

Brian,
Chris suggesting the pressure test is a good one since it may confirm the problem before you go farther on the search. I will say that there's a good chance that the water issue was from the manifolds or the gasket between the manifolds and risers.

I also think Chris's idea to identify a bad manifold is a good one as well. I think its agreeable that when you see rust, and in this case rust in a puddled water pattern, its safe to assume there is a crack somewhere. Or like Peter said a bad riser gasket.

In my limited experience in this department, I've always known an interior crack to be the cause of this....but with out having milky water it made me wonder if it could be another area. Gasket makes sense. I really done feel like preforming those tests when regardless I will be tossing the old manifolds.

Yea mine were toast, in general they are junk. the ports that bolt to the cylinder head are so rusted in spots there is very little left to seal between the gasket and heads. time for new ones.

I did have another boat last year that had exterior cracks, grinned out the cracks filled with JB weird, and its been good to go sense....those will be replaced in the future as well,