Water on plugs

[Reming870]

I started having problems this season starting the engine. Went through everything and noticed water on the plugs and plug threads.

I pressure tested the cooling circuit (antifreeze) and all is OK.

Can condensation cause this much of a problem or is it possible both risers or exhaust manifolds are bad?

5.7 L / 2009 / MPI / Alpha One Gen II

 

[achris]

Re: Water on plugs

I would not expect a 2009 to have manifold problems, especially since they are 'dry-joint'. I would also not expect condensation to be that much a problem. Have you put a scan tool on the computer and read the codes?

Chris.......

 

[Southtowns27]

Re: Water on plugs

Is the water on the exterior or interior of the plugs?

 

[Reming870]

Re: Water on plugs

Is the water on the exterior or interior of the plugs?

Water was present at both.
Exterior and threads were wet, Soaked.
Interior also wet, not soaked, but damp.

Exterior manifold and riser are wet from condensation.

 

[Reming870]

Re: Water on plugs

I would not expect a 2009 to have manifold problems, especially since they are 'dry-joint'. I would also not expect condensation to be that much a problem. Have you put a scan tool on the computer and read the codes?

Chris.......

I have not checked the codes recently, but a couple months ago when she wouldn't fire at all there were no codes.

 

[Reming870]

Re: Water on plugs

Please also note that when and if she finally fires it is rough initially and smoothes out quickly. White smoke (water vapor?) heavy on the start-up then clears quickly. Boat is on a trailer. I am assuming the rough start are the misfired cylinders?? Problem will not occur unless the engine has not been started for a couple weeks.

I did have an overheat issue this year when the sea water pump impeller (motor mounted) failed. Overheat was not severe as I shut down the motor right away on alarm.

New fuel filters, water separator from last time this happened (late-August).

 

[Reming870]

Re: Water on plugs

Bump...
Any other ideas as to why there would be a lot of moisture on the plugs?

 

[SangerDX]

Re: Water on plugs

Please also note that when and if she finally fires it is rough initially and smoothes out quickly. White smoke (water vapor?) heavy on the start-up then clears quickly. Boat is on a trailer. I am assuming the rough start are the misfired cylinders?? Problem will not occur unless the engine has not been started for a couple weeks.

I did have an overheat issue this year when the sea water pump impeller (motor mounted) failed. Overheat was not severe as I shut down the motor right away on alarm.

New fuel filters, water separator from last time this happened (late-August).

Now that sounds like water has leaked into the cylinder(s). Runs rough because of the high compression since water is taking up space in the cylinder, smokes as the water is burnt out. Have you done a compression test? I would think that either a head gasket or intake is leaking water.

 

[Fun Times]

Re: Water on plugs

Any other ideas as to why there would be a lot of moisture on the plugs?

Also with water connected to the stern drive, pull the spark plugs out and crank the engine over while looking for water to spray out of the cylinders.

 

[CharlieB]

Re: Water on plugs

What was the cause of your 'little' overheat? How did you determine that and what have you done to repair it?

Even a 'little' overheat can be enough to blow a head gasket and/or warp a cyl head. A cyl leak down test is in order to determine if there is a problem witih the head or gasket allowing water to enter any cyls.

Sorry.

 

[alldodge]

Re: Water on plugs

Whats the possability that the dry joint risers developed a crack during the over heat?

 

[Reming870]

Re: Water on plugs

I did a pressure test and all was fine.
The overheat was from a failed impeller in the sea water pump.

The problem is on both sides.

How do I test the risers?

 

[achris]

Re: Water on plugs

Whats the possability that the dry joint risers developed a crack during the over heat?

I guess anything's possible...

I did a pressure test and all was fine.
The overheat was from a failed impeller in the sea water pump.

The problem is on both sides.

How do I test the risers?

Usually 'testing' elbows is done visually. I usually pull them off, flip 'em on their heads and start hitting the top of the exhaust passage with a decent screwdriver. If I punch through, it needed replacing. Also do a good visual on the gasket surfaces, and the inside of the elbow, looking for water tracks... If an elbow if faulty, it's usually pretty easy to see.

Chris.........