Engine after seawater in oil pan

[Sid Smith]

hey all

first time poster.  i have twin cummins 6bta’s (1985 recons) with 700 hrs each.  both have been perfect and maintenance has been routine, but i had a catastrophic failure of the after cooler on my part engine and ended up with 2 quarts of seawater in my oil pan.  luckily it was discovered relatively quickly because it was hard to start and throttle up out of the slip.  After many oil changes and a new sbmar after cooler the engine has been running mostly ok.  what has been different is that it still starts up a little slower on turning the key, the throttle response is slower, there’s a little grey smoke (almost looks like steam since it dissipates so quickly) at >2300 rpm (there was none before) and perhaps most concerning is that the pyrometers (0n b0th engines) now read slightly >1000 deg where they used to read 900.  the starboard turbo was found to be binding on its housing and after cleaning off the scale it seems to spin fine.  the port engine’s turbo seems fine.  all valves have been adjusted and there are new air cleaners.  throttle linkage has been checked.  i wonder if all of this reflects some internal engine damage from the sea water or perhaps from something i did during the repair/cleaning processes.  thanks for any help.

Topic

[Sid Smith]

thanks for the reply david.  i appreciate the thoughts.  i think it feels like a combination of things too.  i’ve attached several photos of the engines exhaust to see if that helps. the first four are starboard the last 4 port

[Tony Athens]

Listen to David.. Right now, he’s  got the most basics things covered , & that is where YOU need to start…………You need to post good pictures of your engine as installed in the boat so all of us  can see all, especially the exhaust.. From there, the crew on board here will sort you out as to what’s  “NEXT’.. Remember, good pictures so “ours eyes” see what needs to be seen..   Tony        

[David Marchand]

multiple causes and problems

It sounds like you may have multiple causes and problems ganging up on you. Here are some thoughts:

Hard starting can be caused by air in fuel lines, cold weather or low compression. If when the engine starts it blows a big cloud of white or grey smoke out, that is an indication of compression or cold weather. Cranking and then suddenly starting with no grey smoke indicates air in fuel. You could do a blowby test to confirm low compression- see Tony’t Tips, but unless you are burning oil I wouldn’t worry too much.

High EGTs are an indication of low air or compromised air cooling, but that doesn’t seem to be the case, except for turbo problems that might cause low air flow. You may have a draggy turbo which is limiting turbo performance. Does the engine put out black smoke at high loads?

Scale inside the turbo. Well the most likely cause is sea water backing up into the exhaust due to a poorly designed exhaust system. Another thing is that if you had 2 quarts of seawater in the sump due to a leaking after cooler then another 100 quarts may have passed through the engine and out the exhaust. That might cause corrosion in the turbo, but you said it was the other engine, so ??? It could also have caused ring wear/corrosion which is why your starting is hard and compression is low.

Lot’s to think about. The only thing that I would immediately check is exhaust design. Look in Tony’s tips for proper criteria- 12″ of spill over height above the water line.

David

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