Water in Right Side Pistons, Please Help! Merc 4.3L

[jwharan]

Help!

I have a 1997 4.3L Mercruiser. I am getting water in the 3 pistons on the right side (v6 engine). My mechanic thought it was the manifold, but I replaced it and, it is still getting water in the piston. This is causing a back fire, and the engine is jerking, sounds like it is spitting! Anyone have any idea how the water is getting in there? Thanks!

 

[Haut Medoc]

Re: Water in Right Side Pistons, Please Help! Merc 4.3L

Did he replace the riser as well?
Water can leak from the joint between the manifold/riser & cause this...
Does it happen on the muffs or in the water?.......:%

 

[jwharan]

Re: Water in Right Side Pistons, Please Help! Merc 4.3L

It started at the end of the season, and when I had it serviced, it is doing it on muffs.

 

[jwharan]

Re: Water in Right Side Pistons, Please Help! Merc 4.3L

THe manifold is a one piece manifold, i know they were later replaced with a two piece manifold, as the orginials were recalled? Does the original (which I replaced it with), include the riser or is that seperate? I only installed an original 1 piece manifold, the new two piece was like 1400, and I am just trying to sell the boat, so I didn;t want a huge investment here,

 

[Haut Medoc]

Re: Water in Right Side Pistons, Please Help! Merc 4.3L

Oh, that kind....
You should pull it off & off & pressure test it.....
Where did you find a 1 piece replacement?
They are almost impossible to find....
Was this a new or used one?......:/

 

[DHPMARINE]

Re: Water in Right Side Pistons, Please Help! Merc 4.3L

We shouldn't assume,but is this a two-piece or one piece manifold ? If two-piece it could be the riser.

Hope you find which,and consider repairing the other side of the engine the same way.

Also,that downsized starter you have is capable of stripping the flywheel teeth (and itself).So don't put it off.

DHP

 

[Don S]

Re: Water in Right Side Pistons, Please Help! Merc 4.3L

You say it backfires and sputters, is this when you are starting it or when it's finally running. If it's getting water in the cylinder while it's running, then it won't be the exhaust system causing the problem. It would be a blown head gasket, cracked head or cylinder wall.
If it backfires and sputters when starting then clears up, that would be classic exhaust leakage in either the riser, manifold, or gaset/gasket surfaces.

 

[jwharan]

Re: Water in Right Side Pistons, Please Help! Merc 4.3L

Don S.

YOu are correct that it is sputtering while running, not while starting. I am also leaning towards, it is not the exhaust. What is the best way to narrow it down to a gasket, head, or cylinder wall? I know it is getting into at least 2-3 of the cylinders. It will clear up sometimes, and then come back again. It is a very quick sputter, but can occur quite often as well. Usually 2-3 at a time.

 

[Don S]

Re: Water in Right Side Pistons, Please Help! Merc 4.3L

Sounds like it's time to pull the head and look. Could be you have an old head gasket with steel rings around the cylinders. If you got into salt or brackish water, it could corrode those rings and cause your leaks.
Is your engine raw water cooled?

 

[jwharan]

Re: Water in Right Side Pistons, Please Help! Merc 4.3L

Don S, Thanks for your quick responses. I have used the boat in salt water, and always flushed, but it is also used in brackish water. Yes I believe it is raw water cooled. Can you be bit more specific about what I need to look at, I want to tell my mechanic. Thanks

 

[jwharan]

Re: Water in Right Side Pistons, Please Help! Merc 4.3L

If it is the rings, are we talking about major repair here?

 

[Don S]

Re: Water in Right Side Pistons, Please Help! Merc 4.3L

The rings have nothing to do with seperating water from the cylinders. But water will cause the cylinder walls, rings, valves etc. to rust, which isn't very good if you want your engine to last a long time.
Like I said before, time to pull the head and look. Or have some one do it that knows what they are looking at, and what to look for.

 

[jwharan]

Re: Water in Right Side Pistons, Please Help! Merc 4.3L

Thanks I am having someone pull the head on monday, if anyone can think of anything else, please let me know. Thanks!