Still at a loss, water in one cylinder

So as I posted in a previous thread, I bought a boat with a 3.8l engine. it is a 81 Sea Ray. When I bought the boat I found some water in one of the cylinders. The boat has been sitting for about 3 years. It was run before being put away and it was fine 3 years ago. I tore apart the engine and found no cracks in the block. I had the exhaust manifolds pressure tested at a local shop and they came back as good. The only issue with the manifolds was on the mating surfaces they were pitted pretty good. The shop I took them to went ahead and re-machined them and got them nice and smooth again. When I tore apart the engine I found no signs of rust trails leading into the cylinder or anywhere else. I drained about 2-3oz of water from the one cylinder. I finally got the oil drained and found no water in the oil. The heads look like they are in good shape minus some rust on the valves of the one cylinder that had water in it. I cleaned all the rust off and as far as I can tell everything looks good. So I have no idea how water managed to get into the one cylinder. Any ideas on how this water could have got into there? At this point I am thinking I should go ahead and resemble everything and try running the engine. Before I do I plan on doing a compression check. The boat has spent its whole life in Louisiana and it very rarely gets below freezing. Anything else I should do at this point or be worried about? Thanks everyone.

Re: Still at a loss, water in one cylinder

trooper1822 said:

So as I posted in a previous thread, I bought a boat with a 3.8l engine. it is a 81 Sea Ray. When I bought the boat I found some water in one of the cylinders. The boat has been sitting for about 3 years. It was run before being put away and it was fine 3 years ago. I tore apart the engine and found no cracks in the block. I had the exhaust manifolds pressure tested at a local shop and they came back as good. The only issue with the manifolds was on the mating surfaces they were pitted pretty good. The shop I took them to went ahead and re-machined them and got them nice and smooth again. When I tore apart the engine I found no signs of rust trails leading into the cylinder or anywhere else. I drained about 2-3oz of water from the one cylinder. I finally got the oil drained and found no water in the oil. The heads look like they are in good shape minus some rust on the valves of the one cylinder that had water in it. I cleaned all the rust off and as far as I can tell everything looks good. So I have no idea how water managed to get into the one cylinder. Any ideas on how this water could have got into there? At this point I am thinking I should go ahead and resemble everything and try running the engine. Before I do I plan on doing a compression check. The boat has spent its whole life in Louisiana and it very rarely gets below freezing. Anything else I should do at this point or be worried about? Thanks everyone.

Click to expand...

Ayuh,.... Sounds like yer only viable plan,.... Hopefully, it was the gasket surfaces...

A crack in the head in that cylinder is the only other thing I can think of...

Re: Still at a loss, water in one cylinder

Freezing? Put a light under the motor?Small heater?
They also sell a temp sensitive switch that turns on at freezing temps.

Water in one cylinder.You've checked the manifolds. You've checked the block.
.
Then you have the head????Rust in the intake valve? It's possible the water passage in the head is cracked?
What cylinder???

Re: Still at a loss, water in one cylinder

How covered up was the boat? Could water have gotten into the carb and made it's way into the cylinder?

Re: Still at a loss, water in one cylinder

jerryjerry05 said:

Freezing? Put a light under the motor?Small heater?
They also sell a temp sensitive switch that turns on at freezing temps.

Water in one cylinder.You've checked the manifolds. You've checked the block.
.
Then you have the head????Rust in the intake valve? It's possible the water passage in the head is cracked?
What cylinder???

Click to expand...

It is the front cylinder on the passenger side

Re: Still at a loss, water in one cylinder

wcasey5 said:

How covered up was the boat? Could water have gotten into the carb and made it's way into the cylinder?

Click to expand...

The boat was not covered very well . The person put a piece of plywood over the engine but left the spark arresterr off the carb. But I did not find evidence of water run in

Re: Still at a loss, water in one cylinder

Maybe it rained on it once before he put the plywood over it.

Get it running and see if the problem repeats itself.