The sump is not filled with any liquid at present, i had the lower end filled with marvel and acetone but pulled it all out. Ideas?
Yanmar 3gm 30 engine seized
- Thread starter hunter healer
- Start date
Hi HH.
I went back to your first post to try and figue this one out.
Hi, I'm trying to un seize a yanmar 3gm 30.
Can you tell us the background story of how it originally seized?
Gary
I went back to your first post to try and figue this one out.
Hi, I'm trying to un seize a yanmar 3gm 30.
Can you tell us the background story of how it originally seized?
Gary
Just shoot it, put it out of it's misery. You'll be better off replacing it instead of trying to repair it.
As several of us have said, you need to pull the bottom end. There is no magic potion you can mix up to fix it. Once you get it completely torn down, you can make an assessment of whether it can be saved or not. It is too damaged to get it rotating, and simply put it back in service. You need to do a rebuild. If there are rust areas in the bore as you state, it needs to be honed, if not bored, to be serviceable. You can't do either properly with the pistons in the bore. Taking the engine out and rebuilding it, if practicable, is your next move. If the engine can't be rebuilt, at least it will be out of the way for a repower.
I would encourage you NOT to put acetone or other similar substances in the oil pan. You are creating a hazardous condition in your boat. If it doesn't blow you up, or make you ill, it's hygroscopic. So, once the acetone boils off in your oil pan, it leaves water behind. So, now we're rusting up the crankcase area. Many solvents have this property.
If you get out of your comfort zone, a local machine shop could be contracted to rebuild the short block and head for you. But, you will need to deliver the block and head to them if you want to save a few bucks.
Bottom line, rust in the bores, still stuck, ridge at top of bores - tear down/rebuild (or replacement) required.
I can tell you don't want to do it - I get it. But, the sooner you start, the sooner you'll be sailing. Good luck, and hang tough.
I would encourage you NOT to put acetone or other similar substances in the oil pan. You are creating a hazardous condition in your boat. If it doesn't blow you up, or make you ill, it's hygroscopic. So, once the acetone boils off in your oil pan, it leaves water behind. So, now we're rusting up the crankcase area. Many solvents have this property.
If you get out of your comfort zone, a local machine shop could be contracted to rebuild the short block and head for you. But, you will need to deliver the block and head to them if you want to save a few bucks.
Bottom line, rust in the bores, still stuck, ridge at top of bores - tear down/rebuild (or replacement) required.
I can tell you don't want to do it - I get it. But, the sooner you start, the sooner you'll be sailing. Good luck, and hang tough.
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Just a thought, i believe this motor has auxilary port on the front of the engine to facilitate crank starting the engine see the photo uploaded
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Start with one you believe to be the easiest, most likely not to be hard seized.
Take lots of pictures, everything needs to go back in the same position.
Unbolt the rod cap and remove it. Take a long hard piece of wood, 1.5' of broom handle. Push the piston and rod out from the bottom. You may have to use a 3/8 socket extension and a hammer. Repeat.
Take lots of pictures, everything needs to go back in the same position.
Unbolt the rod cap and remove it. Take a long hard piece of wood, 1.5' of broom handle. Push the piston and rod out from the bottom. You may have to use a 3/8 socket extension and a hammer. Repeat.
I would take the bottom end caps off and drive the pistons out the top of the block using a piece of dowel. I’m sure there is a better way but that’s worked for me.
Some people type faster than others!!
Some people type faster than others!!
That looks great. No real damage in the bottom end. If the bores aren't damaged too bad, it should be rebuildable.
Above suggestions are on point. I would just throw in another $.02.
Take an assortment of dowels, 1x2, and whatever else you can think of to try to get a good non-marring blow on the piston or pin. Try to alternate from side to side. You're likely to splinter a bunch of wood. Take plenty of wood and wear safety glasses.
Unfortunately, you can't drop the crank in that engine due to the way it's made. On the two that are partially down (photo right), you can use a wire wheel and 220 grit wet sandpaper to clean up the exposed part of the bore. If there is a significant ridge, try to knock off the bottom corner with the sandpaper before you try to drive them out. Even a small sharp ridge will stop you cold when the rings hit it. Get the exposed part of the bore as smooth as you can, suck out the debris with your shop vac and put some assembly lube, grease, or oil around the pistons, and drive them out as described above. Leave the left rod cap on until you get the right two out. Once you get two of them out, you may be able to rotate the crank to get the one on photo left down. I would do it last. Again, don't go all Conan on the crank bolt. If you can't free it with a good pull with a 16-18" handle, just stop and drive it out. If you can move it down, you can hone it a little and possibly cut the ridge to help the rings get by. If there isn't room for honing or the ridge cutter, then simply repeat the wirewheel sandpaper process.
Good luck. It's looking better than I hoped.
Above suggestions are on point. I would just throw in another $.02.
Take an assortment of dowels, 1x2, and whatever else you can think of to try to get a good non-marring blow on the piston or pin. Try to alternate from side to side. You're likely to splinter a bunch of wood. Take plenty of wood and wear safety glasses.
Unfortunately, you can't drop the crank in that engine due to the way it's made. On the two that are partially down (photo right), you can use a wire wheel and 220 grit wet sandpaper to clean up the exposed part of the bore. If there is a significant ridge, try to knock off the bottom corner with the sandpaper before you try to drive them out. Even a small sharp ridge will stop you cold when the rings hit it. Get the exposed part of the bore as smooth as you can, suck out the debris with your shop vac and put some assembly lube, grease, or oil around the pistons, and drive them out as described above. Leave the left rod cap on until you get the right two out. Once you get two of them out, you may be able to rotate the crank to get the one on photo left down. I would do it last. Again, don't go all Conan on the crank bolt. If you can't free it with a good pull with a 16-18" handle, just stop and drive it out. If you can move it down, you can hone it a little and possibly cut the ridge to help the rings get by. If there isn't room for honing or the ridge cutter, then simply repeat the wirewheel sandpaper process.
Good luck. It's looking better than I hoped.
Have you considered getting a book on basic engine rebuilding?
Thank you! Question which direction does the motor turn under propulsion? Looking at the motor from the front pulley!
what keeps the cylinder liner in place when we’re pounding the piston?
There are various ways of inserting piston liners
All of them requiring much more energy than a bloke with a hammer and a lump of wood.
As mentioned, remove all of the bottom bearing caps and if you can shape you wood so it fits into the bottom of the piston, then whack away.
gary
There are various ways of inserting piston liners
All of them requiring much more energy than a bloke with a hammer and a lump of wood.
As mentioned, remove all of the bottom bearing caps and if you can shape you wood so it fits into the bottom of the piston, then whack away.
gary
Okay i removed bottom brg caps and started hammering with a good size dowel and hammer and the 2 front pistons and liners came up with the pistons, the 3rd piston is giving me troucle i hit ir wire wheel and some kroil penetrating fluid!
Any thoughts here i think im in uncharted territory
Any thoughts here i think im in uncharted territory
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You're probably pushing the liners out because you didn't cut the ridge off the top of the cylinder before pushing the piston out. Again, a book on basic engine rebuilding would have helped.
Did you mark the big end bearing caps so they go back the same way? And the shell bearings?
Where are you putting the dowel to hit it?
https://www.cylinderheadsupply.com/...HILXNh-OqZDxEI-j2r4x837CBsp4MmVBoCs60QAvD_BwE
Did you mark the big end bearing caps so they go back the same way? And the shell bearings?
Where are you putting the dowel to hit it?
https://www.cylinderheadsupply.com/...HILXNh-OqZDxEI-j2r4x837CBsp4MmVBoCs60QAvD_BwE
In all likelihood, new liners and pistons were in your future anyway. Hopefully the third one will come out without too much grief. If you haven't tried already, take the rod cap off of the third one, move the crank throw away from the rod, and smack it from the top side a few times (using wood against the piston). Maybe it will move down easier.
Did they move at all before the liners let go? Photo doesn't look like it.
You can give them a good look when they're out and see what kind of shape they're in. You might take them to a machine shop and see what they think. They can press the pistons out for you if you don't have a press. Pressing may break the piston or deform the sleeve if they are badly corroded.
Not sure a picture is going to be enough to determine condition, so you probably need to get someone there to look the pistons/sleeves over if you're contemplating re-using them.
Good news that the crank is free. Looks like the heavy corrosion was confined to the top end.
Did they move at all before the liners let go? Photo doesn't look like it.
You can give them a good look when they're out and see what kind of shape they're in. You might take them to a machine shop and see what they think. They can press the pistons out for you if you don't have a press. Pressing may break the piston or deform the sleeve if they are badly corroded.
Not sure a picture is going to be enough to determine condition, so you probably need to get someone there to look the pistons/sleeves over if you're contemplating re-using them.
Good news that the crank is free. Looks like the heavy corrosion was confined to the top end.
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I got the last one to move up 1/4 inch with the liner but the connecting rod seemed to jamb up probably due to the aluminum rod that was holding the connecting rod up so i could get the rod could all the way to the inside of the piston and pound thr aluminum rod? Now what