elbows gaskets check

[gordond]

I have encountered water in my oil and am trying to find the problem asap. time is limited. shorts summers and long weekend coming.
The engine is a 1999 merc 350.
Last time out she was running fine and just died. She would not idle but did run when the trottle was opened up about 1/2 way. Then we noticed water in the oil but not a large amount.
One engine builder told me if the the spark plugs are rusty then water got into the cylinders. This is not the case. However i was wondering if a small amount of water was getting into the cylinders then this is why it would not idle, but when giving her more throttle the fuel out ratioed the water.

I've read the risers/elbow gaskets could leak and let water back into the valves?
Sooo i took of the elbows. see pics. They seem ok BUT can someone confirm?
My next question is can the exhaust manifold gaskets leak the same?

also she slightly overheated the prior time out. maybe 210 degrees for a small time. which is probably the water/oil problem now.

 

[jerryjerry05]

Re: elbows gaskets check

Manifold looks ok.Now pics of the risers.In and out both ends.
Does the exhaust downtubes have the flappers still in them?#6 in the pic.
Water flows back in the riser/manifold when they are gone.
Salt water or fresh? Fill out the profile.Post your results and tell us if it fixed.J

 

[Bondo]

Re: elbows gaskets check

My next question is can the exhaust manifold gaskets leak the same?

Nope,.... No water at those gaskets...

 

[gordond]

Re: elbows gaskets check

thx JerryJerry. My profile has been updated to include my particulars. I was not aware of this. We are in fresh water too.

This is an inboard with vdrive and there are no risers. The elbows direct exhaust towards the bow, then there is a 90 degree exhaust pipe elbow directing downward, followed by a straight pipe approx 2 feet... to be even with the bottom of the oil pan, and then another 90 degree exhaust pipe elbow directing towards the stern AND finally a straight pipe out through the transom. I wish i had the boat here i would just take a pic!!!

I'm not sure if there are water shutters but could they melt and cause the same problem as a melted flapper? See attached pic. It seems the exhaust elbows are well above the waterline so there would be no water coming in this far. But that's my inexperienced guess.

I will update the final result as i have brought it to an engine builder. As i mentioned time is essential. thx to all.

 

[Philster]

Re: elbows gaskets check

At idle or very low RPM, that is when an engine can suck back into the cylinders any water that might have entered the exhaust system. Under more RPM, there is no sucking action, so she'll run better or even great under higher RPMs.

Water that is present in the exhaust ports gets sucked in at low RPM/idle and affects engine. Water that is present in the exhaust ports gets blown out at higher RPM and you might have a fine running engine under higher RPM.

 

[jerryjerry05]

Re: elbows gaskets check

That makes a difference.Any info you can give will help.You said 99 350.Is that 350HP or 350CI.Kind of boat.Any other description will help.Get some pics.J