Water in cylinder of my 2011 Mercruiser 3.0 MPI EC

[ChrisMia]

Sure would like to know how the motor ever ran without the CAT's. There are sensors in the mans which have input to the PCM

From what I've read on the web, the second oxygen sensor only turns on service light

 

[ChrisMia]

Total salt water cooled motors last 8-10 years her in NW Florida, if they are flushed with fresh water after every trip. The heads usually rust out ot through passages and you get water into combustion chambers. That old of a salt water cooled, go find one to rebuild from a junk yard. Just my 2 cents, since I have been in your shoes. You never did indicate if it was antifreeze cooled?

the engine is open cooled

 

[ChrisMia]

Fill the manifold water jacket with acetone, then look up into the int/exh ports with a flash light every couple of minutes for leakage, wet line, discoloration. If it's a big crack it will start flowing pretty quick, but a hair line crack could take a bit to leak, and only show up as the surface getting moist/wet.

My manifold had a hair line crack (filling/rusing cyl 3 and 4) and I could only see a moist line, acetone was evaporating almost as quick as it was leaking, but it still leaked enough to fill the rear cylinders. Manifold was probably leaking more when the engine was hot...

I try to do this test, but is crazy the weight of this manifold, around 100 lbs

 

[alldodge]

From what I've read on the web, the second oxygen sensor only turns on service light

Would like to know where that was listed.
The O2 sensors tell the PCM how to adjust fuel supply level. The light is turned on by the PCM when a code is set

 

[Lou C]

Not true if the O2 sensor system is set up like that for vehicles, the upstream O2 sensor adjusts fuel trims and the downstream will monitor catalyst efficiency. You can certainly get an upstream O2 sensor code. Personally I would not have an I/O with cat converter exhaust. Just a whole lot of extra expense and 2 very expensive heat generators in the engine box. No thanks EPA.

 

[alldodge]

What's not true

 

[Lou C]

From what I've read on the web, the second oxygen sensor only turns on service light

this
I got a code on my '07 Jeep for an upstream O2 sensor that was switching from rich/lean too slow. Caused by a small crack in the cat converter pipes and fortunately was replaced under the 80K warrantee (part alone was $1200)
so you can get codes from either the upstream or down stream O2 sensors, assuming it uses the same OBD-II protocols.

 

[Lou C]

Thank goodness I can still use these, instead of dealing with EPA mandated heat generators in a fiberglass boat. Never ever will I get an inboard with cats.

BTW, my landscaper has a late model boat with a Merc 4.3 in it and its time to replace the exhaust manifolds (salt water every 5-7 years) he got an estimate of $4500 for this.

 

[alldodge]

ok your guessing just like I am, and you don't know, so should be maybe not true

08 Ford will stop dead on the road if the O2 thinks its getting to hot
08 Dodge goes into limp mode if O2 messes up
Other vehicles do other do other things.

First liar doesn't stand a chance

In any case this is a newer PCM then either of our car/trucks.

 

[GA_Boater]

Two thoughts;

1) Road vehicle and marine can't be compared when talking about emission control. There are too many variables and only the basic operation is the same.

2) What does all this ECU, cats and O[SUP]2[/SUP] sensor discussion have to do with water in the motor, whether the motor has cats removed or not?

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[alldodge]

2) What does all this ECU, cats and O[SUP]2[/SUP] sensor discussion have to do with water in the motor, whether the motor has cats removed or not?

From my question about wonder how the motor even runs without the CATs and the OP response.

Looking into all angles such as over fueling, and anything else that may happen because of the mod. If it didn't sink, just how the water got in. Same ole iboat discussions

 

[GA_Boater]

Well, it isn't running and from the looks of the head and pistons, it's been dead for a long time.

 

[Scott Danforth]

Well, it isn't running and from the looks of the head and pistons, it's been dead for a long time.

yep....... its not only toast....... its burnt toast

 

[tank1949]

I try to do this test, but is crazy the weight of this manifold, around 100 lbs

I have 4 of them on 2 383s! I feel your pain! LOL

 

[dlogvine]

can take it to any machine shop and have them magnaflux it. I would also check out the head if it is not a manifold, could be a crack there too.

 

[ChrisMia]

After a while we put a new head, new gaskets and assembled the engine. However the engine did not start, the starter works great. ​​​​​​We checked everything and there is no power in the engine electronic circuit, but some dash instruments work(oil pressure, trim , fuel , temperature and voltage), the buser works but the obd lamp not.

 

[ChrisMia]

Any idea why there is no power in the system ?

 

[ChrisMia]

[No message]

 

[ChrisMia]

[No message]

 

[ChrisMia]

[No message]