Engine Due Diligence

[nauticalnovice]

In a completely hypothetical ideal scenario where a vessel with, say, mid life engines is being considered for a reasonably long voyage/delivery, what sort of things would you absolutely want to check? Assume the vessel has recently been though a storm that might have involved following seas and/or an overwhelmed waterlift muffler.

My (inadequate) list thus far is:

1 - verify oil quantity via dip-stick (pay particular attention to abnormal oil color/consistency); verify fuel quantity and filter condition (for a visible fuel filter/oil-water separate, look for the presence of fuel, quality of fuel, accumulated sediment/gunk); check air filter condition and quality

2 - verify belt(s) type, tightness and integrity (try to guess roughly how long the belt has been installed/in use)

3 - attempt to manually turn the crank shaft; if it doesn't turn, use compression releases/adjust belt tightness; if it still doesn't turn, re-tension belts, but leave compression release engaged (open)

4 - verify battery state (charged; able to provide CCAs); isolate electrical loads for starter battery use; verify panel warning lights/buzzers; pump injector primer

5 - attempt to start engine with compression release open; if engine turns over stop, close compression release and attempt start with compression release closed;

6 - if the engine does not turn over, verify starter operation by listening for solenoid engagement; keep compression release open

7 - if solenoid engagement is happening, attempt to isolate failure to turn the crank shaft over to either the starter or internal engine issues.

I guess this is where I run out of ideas about how to diagnose a seized engine vs a bad starter. Sort of pulling the engine head (not something I want to do for simple diagnosis), I'm out of ideas about what to look for in a potentially seized engine. Would sticking a bore scope into the head area reveal anything? I mean, obviously, if there's sea water in the head, something has gone drastically wrong. Just tyring to figure out of there's any obvious way to diagnose a non-turning crank shaft. I've got follow-on lists in the event that I get past this one issue.

Suggestions?

[sailorboy1]

Hell I would just change the oil, check the belt, and turn it on and run it.

[Pete7]

Originally Posted by sailorboy1

Hell I would just change the oil, check the belt, and turn it on and run it.

Me too and if it didn't sound right then the compression tester.

Pete

[hellosailor]

"I guess this is where I run out of ideas about how to diagnose a seized engine vs a bad starter."

If that was the goal? Well, put a long wrench on the flywheel and just see if it turns over. If it don't turn, it is seized. Everything else aside, you should still be able to turn the engine over if it has not seized.

If you're looking to see if there was water damage, send out an oil sample for analysis (Blackstone Labs being the online goto place in the US) and consider buying a cheap $25 borescope to put down the injector holes, to look inside the cylinders.

Starters are also pretty easy. Standing at the engine, listen for the "chunk" of the starter engaging. If the "Bendix" doesn't engage and disengage, you have a problem. If the starter doesn't spin up, you have a problem. But those you can usually refine with a voltmeter and an ear, checking to see if it is getting and using power, and engaging, in the first place. If it is engaging, drawing power, and not spinning up? You whack it with a hammer to see if a bare spot has it stuck. If it still doesn't spin up, you cut the power before it burns out, because you've probably got a seized engine.
Burn that bridge when you cross it.

[Dymaxion]

Ditto the oil change. Oil floats. Oil on the dipstick doesn't tell you if the Oil pan is half full of water. Dump the old oil, fill with cheapo oil, run until warmed up and dump it. If it looks like chocolate milk there was water in the system. Then install new oil and filter.

Regarding the starter, not knowing how difficult access is, I'd say remove it and take it in to a rebuilding shop (non-marine!!) and get them to overhaul it completely. Peace of mind for a few more years.