Starting engine after two years on the hard

[and4ew]

Due to covid and other stuff my boat has been on the hard for two years. I have a checklist of filters and fluid changes, things that I have never done on a diesel but seem pretty straightforward.

The engine is a 2GM20F with 900 hrs. Very well maintained by the PO. My boat is located in Nova Scotia so there are temperature fluctuations. My question is: after not running for two years, should I remove the injectors and put some Marvel Mystery Oil in the cylinders ander it soak for a while?

[roverhi]

Wouldn't hurt to oil the cylinders/pistons. Probably get by with squirting Marvel in the air intake with the compression releases activated. Don't think I've ever gone more than a year but after a lengthy hibernation have just turned the engine over for less than a minute with compression releases and the raw water intake seacock closed. Might want to slap a socket and ratchet on the crank pulley and turn it over by hand just to be sure nothing has frozen up in the respite.

[EngineerRetired]

I've re-fired diesel engines that have sat a decade or more. Change filters, check coolant, bleed any air from fuel lines, maybe turn it one full revolution by hand and then normal starting procedures. Don't make it any more complicated than need be.

[C420sailor]

I like to crank a stored engine until it develops oil pressure before letting it fire, but that’s just me.

[Pauls]

The fitting which is used to send oil pressure to the oil pressure sensor often has an additional port, sealed with a screw. If you remove that screw (or the oil pressure sensor) you can use a pump type oil can to pressurize the whole oil system and push fresh oil onto the bearings. It is an easy thing to do, and if an engine has been sitting for a long time it's a good idea.

[wholybee]

On a gas engine, I would pull the distributor and use a drill to run the oil pump to get oil to the bearings before turning it over. I'm not sure how to do that on a diesel, but if you can find a way to spin the oil pump before you crank it, that would be the best thing you can do before starting it.

Otherwise, just make sure it has clean fresh oil in it.

[Wotname]

Originally Posted by EngineerRetired

I've re-fired diesel engines that have sat a decade or more. Change filters, check coolant, bleed any air from fuel lines, maybe turn it one full revolution by hand and then normal starting procedures. Don't make it any more complicated than need be.

With he said ^^ (my emphasis added).

If you are pedantic (like me and some others), yes spin the engine over decompressed for a few seconds to get oil pressure up before starting.

[sail sfbay]

Originally Posted by and4ew

............My question is: after not running for two years, should I remove the injectors and put some Marvel Mystery Oil in the cylinders ander it soak for a while?

No reason to..........it is not like a carbureted gasoline engine that will gum up if not fogged before lay up. After returning from 3 years overseas my diesel Yanmar- driven sailboat and truck and gasoline-driven skiboat (fogged prior to lay up) started righ up without any maintenance other than oil and filter changes.

[dadster3]

If the engine is raw water cooled, replace the water pump">raw water pump impeller and gaskets. Almost certainly the impeller has taken a set and is also dry. At the very least squirt a generous amount of glycerin into it through the intake hose from the strainer.


If it has dried out and isn't lubricated you run the risk of having a bigger task to find and remove any impeller pieces that break off. Any could be lodged in a hose, perhaps blocking other pieces. Barring that, any pieces will probably be in the end of the heat exchanger where the raw water comes into it.


All this is from my own experience from letting an engine sit for 2 years.

[sailcrazy]

Following. There was just another forum on this similar subject. It's at:
https://www.trawlerforum.com/forums/...ine-59206.html .

[Midnight Son]

Originally Posted by C420sailor

I like to crank a stored engine until it develops oil pressure before letting it fire, but that’s just me.

+1Best way, as oil will drain from the bearings after ~4 days or so.

[Cheechako]

If stored well I wouldn't worry about it.
The easier/better option is to crank it real short turns while spraying some diesel in the intake. This will coat more things like valve stems etc than spraying in an injector hole.

[valhalla360]

Originally Posted by sail sfbay

No reason to..........it is not like a carbureted gasoline engine that will gum up if not fogged before lay up. After returning from 3 years overseas my diesel Yanmar- driven sailboat and truck and gasoline-driven skiboat (fogged prior to lay up) started righ up without any maintenance other than oil and filter changes.

The carb might gum up if not put to bed properly but the interior moving parts of the block are not much different from diesel in terms of getting oil moving thru the system.

No harm to manually crank it 2 full revolutions so all the parts have had a chance to run thru the full 4 cycle process but not critical. 1 week or 1 decade...the oil that will drain has drained. Within a few seconds, oil will be flowing thru everything.

Up north, this happens on an annual basis and it's nothing to see 30-40yr old motors that aren't worn out.

[Boatyarddog]

Originally Posted by EngineerRetired

I've re-fired diesel engines that have sat a decade or more. Change filters, check coolant, bleed any air from fuel lines, maybe turn it one full revolution by hand and then normal starting procedures. Don't make it any more complicated than need be.

Agreed!
Also, agreed with dadster3
Only addition is to check the fuel condition.
SV Cloud Duster

[garyfdl]

If the engine was prepared for storage / winterized, meaning the water pump is flooded with antifreeze, it should be good to go. If it sat dry?
Change it. As another poster said, you don't want to be chasing bits of broken impeller in the cooling system.

If the pump is good, I would turn the engine over by hand a dozen or so times, with the compression released, just to move some oil around. (If you don't have the hand crank a socket will do.) Then I'd try and start it. If you weren't having problems before, it should start right up.

FWIW I have the same engine and am in pretty much the same situation. The boat I bought has sat 3 seasons (including this one). I did the above, and it fired right up. Full disclosure - I did have the injectors rebuilt - but that was because there was a fair amount of black soot on the transom and I wasn't familiar with the engine. So, I pulled the injectors, took them in to be tested, was told they needed rebuilt and went ahead. They looked 'rough' and, for $237 and after 40 years, I thought it was worth it.