Bottom half of D2-40 submerged

[D328jet]

Hello everyone,
I’m looking at getting a Volvo D2-40 with sail drive into working condition. The bottom half was submerged for a day or two in salt water and then was recovered (boat put on dry and drained). ECU was above the water so maybe ok? Definitely replacing starter and alternator. Checked oil, looks good. What other issues may I run into? Oil pressure sensor probably needs replacing? Wiring to that? Anything else on the lower half I probably need to replace or be wary of before I commit to the revival? Could there be fresh water loop intrusion? Could salt water have entered the crank case? Ecu wiring may all need replacing? Is it a total loss? Should I just replace the engine? (I would rather not if I have a choice).
Thank you all. I tried to be as specific as possible. Let me know if more info needed.

[sailormed]

1st question: Can you turn the crankshaft?

[tkeithlu]

Ditto to sailormed. If the bottom half was in salt water, then the crucial question is whether the crankshft and big end bearings have been damaged. If they have, then you'll have to pull the engine, drop the pan, and replace IF the crankshaft itself is not damaged. By then, you are getting perilously close to replacement.

If the crank turns, then at least you can experiment - new oil, give it a try. I would not trust it until it had some hours on it without rumbles from the crankshaft bearings or worse.

[D328jet]

Originally Posted by tkeithlu

Ditto to sailormed. If the bottom half was in salt water, then the crucial question is whether the crankshft and big end bearings have been damaged. If they have, then you'll have to pull the engine, drop the pan, and replace IF the crankshaft itself is not damaged. By then, you are getting perilously close to replacement.

If the crank turns, then at least you can experiment - new oil, give it a try. I would not trust it until it had some hours on it without rumbles from the crankshaft bearings or worse.

Thank you SailorMed and TKeithLu.

I did not check this. The engine wasn’t running when it was flooded. Is there an easier way to check this other than putting the transmission in gear and trying to turn the prop? I believe I would need to put a battery to it and try to starter just to see if it would turn over. The compression would stop me from turning the crankshaft manually correct? This becomes dependent on whether the starter works or not?

If I ask, how would water have gotten into the big end bearings or crankshaft? Are these vented? The water did not come over the top of the dipstick or up to the ECU so I’m trying to figure out where the water could have gotten in.

[PippaB]

Had the same thing happen when a rudder shaft seal failed with the exact same engine. Water up to mid-engine before it got controlled and pumped out, then it sat for ~24 hours until we got to a dock with fresh water.

Removed ECU, the connectors are sealed and were all dry inside. Removed fuse plug from top of ECU, dry inside. Pulled starter and alternator. Checked intakes, dry. Flushed whole thing copiously with fresh water. Lots and lots of fresh water. No water in oil, oil level normal, but changed anyway. Transmission did get water, drained, flushed, used water absorbing additive (basically alcohol). Stripped alternator and starter, flushed with fresh water, then with lots of WD40 (the “WD” does stand for water dispersant after all). Reassembled all.

The engine now has ~100 hours since all of that and (knocking on wood) has had no problems. I don’t fully trust the starter or alternator even so, but I have spares on board. Changed the oil three times in the first 10 hours. Changed the transmission fluid about twice that.

Total investment was 6-8 hours of my time and a couple hundred dollars in fluids and filters. Well worth it to me.

[D328jet]

That is very encouraging and consistent from what I have been hearing. Unfortunately in my situation the boat has been sitting for a month out of the water so I’m less optimistic about the starter/alternator but more so about the rest. I was told to check the flywheel and the bumper plates in the transmission too. All the rest will be done as you described.

One thing though, did you have to replace any of the sensors: oil pressure/temp/rpm etc.?

[Pete7]

Originally Posted by D328jet

I was told to check the flywheel and the bumper plates in the transmission too. All the rest will be done as you described.

The later versions of this engine has an electrically isolated engine from the gearbox to try and stop electrolysis. There should be a gasket between the gearbox and engine and I think caps for the bolts were they go through the gearbox. Would be worth cleaning all this area out thoroughly.

Pete

[tkeithlu]

You can turn over the engine manually with a breaker bar and socket on the nut on the front end of the crankshaft. Just be damned sure that the fuel is cut off first, because having the engine start while you have a breaker bar on it could spoil your whole day. Expect to feel the compression as the crankshaft rotates.

[PippaB]

Originally Posted by D328jet

....One thing though, did you have to replace any of the sensors: oil pressure/temp/rpm etc.?

Have not, so far, had to replace any sensors. Same fresh water followed by water removal at the connectors.

[tkeithlu]

Sailormed's and my point is that if water got into the crankcase, your problems can escalate all the way to your owning a rather expensive steel sculpture. That might be the case, and you want to eliminate the possibility before spending money on a new starter, etc. There's a very good likelihood that water did not get in, or got in but did no damage. It's not a matter of "how could it", it's a matter of "did it?"

Drain the oil, and see if water comes with it. Turn the engine over manually, and see that it is smooth and has compression. Then proceed with dealing with the known problems.

[Dann]

Similar thing happen to me, but on md22, starter and alternator had to be replace and all the wiring, relays and fuses, due to stray electrical currents while submerged.
No water got into the motor, but i was very worried about the timing belt and tensioners and also the bell housing was full of water as it didn't self drain so make sure you check in there and of cause the gearbox could have water in it