Cat 3412 1997 problems

Sounds like you have water in there. Pretty much the only thing that can explain the high oil level besides diesel but you d have smelled the diesel in the oil

Oil full of fuel or water.
Both bad news.

I hate offering a new member bad news.
Especially on one of our favorite engines.
Please don't keep turning the engine over. Bent rods come from this.

First thing I would do is drain the oil to see what you have. That will tell you if you have too much and what you have in there.

Sure it could be the starter wiring or the batteries but that doesn’t explain the high level on the dipstick

Do you have any evidence of a raw water leak near the water pump or elsewhere in the area? Isn’t the raw water pump gear driven on the 3412?

water being sprayed around still doesn’t explain rust inside the valve cover on one bank or the higher oil level. Speaking of which, is it still high? Are you sure the oil is pure and not emulsified / milky?

you should sent an oil sample for analysis before doing anything

next step would be to pull the injector and scope the combustion chambers.

The gear driven Sheerweed raw water pump is isolated from the engine.
Any water leak on the drive shaft would leak out as any oil leak would leak out thru the same dribble hole.
If a pile of water was spraying over Walker Air-Seps, some water may drain into the sump.

Witch valve cover, there could be 6, 4 or 2 of them pending the model?
Valve cover with an open vent?

Yes, any leak would come out of the weep hole but it is unlikely to be sprayed by the belt as if it was a belt driven pump

Belt driven alternator and/or aux device?
Raw water pump and weep hole would be to the port side of the engine. Other stuff would be low or to stb.
Hummmm..

What did the coolant recovery bottle level look like??
Low or dirty?

Lets review;
Oil level was down. Now it is up. Oil is not yellow.
Oil seems old and some sludge.
Light rust under one of the valve covers.
Was this a vented valve cover???
Expansion tank and coolant recovery tank are at normal filled levels.
A water mist may have landed on the engine, lil drip from the Sherweed pump onto the alternator belt. Don't forget to spray the alternator down with WD40 and let dry.
Air filters should not have received a heavy amount of water????

Engine will not starter turn over.
Have you tried baring the engine over? Harder to turn that the other engine??

I'm still thinking fuel washing the liners.
You may not smell the fuel in the oil. And it won't take much.
You can send the oil to a lab.