engine damaged?

[Ash]

due to a recent failled seacock the inboard engine (mercedes 636, 42 hp) on our yacht was partially submerged about 1/2 up!, the water entered through the oil dipstick and 10 litres of water was removed, the water did not reach the air intake and the dipstick was the only possible entry point.

is this total rebuild time or is luck on our side and an oil change will surfice!.

any personal experience out there?

 

[Gaffer]

No personal experience of this, but I would have thaught that as the water didn't reach the air intake just change the oil and filter and get it started preferably as soon as possible or the inside of the sump, crankshaft con-rods etc will start to rust. If it starts then you will probably be ok, if it dosen't start check that no water got into the fuel.........

 

[yoda]

Provided you haven't run the engine a good oil change (or 2 ) should do the job, sooner rather than later. Once done it may be worth turning the engine over without starting it if possible just to try and displace any water that may have got into the bearings etc. If the engine has sat with water in it for more than a few days I may be a little more worried and consider engine removal and sump removal and inspection.

Yoda

 

[mtb]

Is it salt water or fresh.
Two gallons is more than enough to get up to the pistons , mind you the oil would have been on top of the water .
Salt it must be taken out and stripped .
Fresh well mabey just mabey but why risk it .
After all the damage from silt or sand will mean that before long the bearings will let you down .
What about the gearbox !!
Mick

http://homepage.ntlworld.com/boats
I want a big steel ex trawler / tug v / cheap or swap for tug

 

[vyv_cox]

To start with, will it still turn over? Rust on the bores very quickly prevents pistons from sliding and the engine may well be seized already. Even if not, I think there's a very good chance that you can recover the situation without spending too much but I would certainly not try to run the engine without checking inside. Remove the sump and inspect, that should tell you how far up the water came. Best treatment is to take off big-end bearings and check them, then move each piston individually with paraffin as a lubricant. If all seems well you may get away with it.

Any other components that have been submerged, e.g. starter motor, oil pump, gearbox, solenoids, transducers, alternator, will need to be inspected.

Ideally, you should have done all this immediately the problem was known. If this is seawater it is worth flushing everything asap with fresh anyway.