Water in cylinders after sitting

[jchandu]

5.7 MPI Mercruiser, with a raw water pump....Frequently, if the boat is parked in the water (at anchor or at dock), when we restart the engine it is hydrolocked.

I have removed the exhaust manifolds and risers and checked for obstructions, none. I replaced the dry fit gaskets with one restricted and one open per side. The restricted gasket went on the bottom with the restricted hole facing the front of the engine.

It will started sometimes if we try and engage the starter a couple of times, when that has failed, removing the left hand spark plugs results in water in the cylinder. We remove the water by turning the engine over with a breaker bar. The plugs show water on them water will come out of one or two cylinders.

Note, this does not happen all the time but seems to happen the longer the boat is parked, almost like water is trickling in through the exhaust manifold, though an open exhaust valve and into the cylinder.

Thanks

 

[Rick Stephens]

Probably has a cracked manifold...should probably remove them and test by filling the water passages with acetone. Cracks will show up.

 

[Scott Danforth]

If you boat in salt water, you may want to just replace the manifolds

Have you verified your SWL to riser dimension

 

[Bondo]

5.7 MPI Mercruiser, with a raw water pump....Frequently, if the boat is parked in the water (at anchor or at dock), when we restart the engine it is hydrolocked.
It will started sometimes if we try and engage the starter a couple of times, when that has failed, removing the left hand spark plugs results in water in the cylinder. We remove the water by turning the engine over with a breaker bar. The plugs show water on them water will come out of one or two cylinders.

Ayuh,.... Welcome Aboard,.... Don't do That, you'll snap the crankshaft bolt,.....

Which cylinder is gettin' the water,..??

I had such a situation once, water always from the same cylinder,....
It was a cracked head,.... Vortec heads are thin around the valves,....

 

[tpenfield]

As far as the exhaust manifolds . . . you said you inspected and replaced the gaskets. Were that mating surfaces of manifold/riser in good condition or deteriorated?

Left hand spark plugs as in 'port' side of engine (so cylinders 1,3,5,7)?

A crack in the manifold or a blown head gasket could also be possible causes.

Maybe see if you can do a cooling system pressure check or at least a cylinder leak test to start narrowing the possibilities.

 

[jchandu]

If you boat in salt water, you may want to just replace the manifolds

Have you verified your SWL to riser dimension

The boat was in salt water, now strictly fresh water.

Not sure what SWL is.

 

[Scott Danforth]

The boat was in salt water, now strictly fresh water.

Not sure what SWL is.

Static Water Line

 

[jchandu]

As far as the exhaust manifolds . . . you said you inspected and replaced the gaskets. Were that mating surfaces of manifold/riser in good condition or deteriorated?

Left hand spark plugs as in 'port' side of engine (so cylinders 1,3,5,7)?

A crack in the manifold or a blown head gasket could also be possible causes.

Maybe see if you can do a cooling system pressure check or at least a cylinder leak test to start narrowing the possibilities.

Mating surfaces are good, there is heavy corrosion around the water passages, which we clean up.

My mistake, right hand side of engine, (2,4,6,8)

Engine was just rebuilt in the summer, so it has new headgaskets

 

[Rick Stephens]

Need to find the source before you bend a rod or break a piston.

 

[Scott Danforth]

Mating surfaces are good, there is heavy corrosion around the water passages, which we clean up.

My mistake, right hand side of engine, (2,4,6,8)

Engine was just rebuilt in the summer, so it has new headgaskets

And how did you clean up the corrosion?

 

[jchandu]

And how did you clean up the corrosion?

Used a die grinder to removed the crusted rust

 

[jchandu]

I think I am just going to remove the manifolds, check them using acetone and replace both sides with new If cracked

 

[Bondo]

I think I am just going to remove the manifolds, check them using acetone and replace both sides with new If cracked

Ayuh,..... If you don't find joy there,....

Drain the water from the block, isolate it, 'n pressure test it with 'bout 15 psi of air, 'n listen,.....
Then follow the sound to the leak,.....