Thank you everyone for your messages on in seizing my yanmar 3gm30. I have one last option and I purchased 2 gallons of marvel myster oil and will flood the engine top to bottom and wait and pray! My next option is to remove the cylinder head! I have been pouring marvel into the injector ports and 1 moves fast 2 moves slower and 3 moves almost not at all ! What should I know about removing the head? Does the cast iron water tank need to be removed? I'm thinking possibly there is water / rust in the cylinders on top of the pistons?
Seized engine cylinder head removal
- Thread starter hunter healer
- Start date
most likely scenario is that one or more sets of piston rings have rusted to the cylinder wall. Removing the head is a lot easier if the heat exchanger housing is removed.. best to strip the head of rocker arms and pushrods and anything you can get loose.. Once the head is off, you can see which one is frozen from the rust trace on the walls.. then you can take a wood block and a hammer and put the block into the cylinder and bump the piston top with a hammer.. this will often loosen the rings and the engine will begin to rotate.. Try to get all rust out BEFORE turning it any further so that the cylinder walls aren't scratched..
Many folks will install new rings all around and have the head looked at to see if the valves need to be repaired. Good Luck.. You can refer to the GM shop manual in the "General Downloads" section of "Boat Info" from the top bar of this page.
Many folks will install new rings all around and have the head looked at to see if the valves need to be repaired. Good Luck.. You can refer to the GM shop manual in the "General Downloads" section of "Boat Info" from the top bar of this page.
I wish someone would do a nice, detailed YouTube vid on complete marine diesel rebuilds. I would almost be willing to try it myself just with my knowledge of V8 tear-downs and rebuilds. I can point to a couple dozen good YT vids on this process. When it comes to engine rebuilds you'd be surprised by a few things;
- Most people should be able to remove a sailboat diesel using their boom as crane and some simple tools like a come-along.
- Tearing down an engine to its bare block requires very few specialized tools. Correct reassembly involves a few more than that, but most you can borrow from auto-parts stores these days, buy cheap used, or borrow from a motor head buddy.
- The boring and honing of cylinder walls and other machine time isn't as expensive as you might think. Add to that a marine diesel is significantly smaller than a V8 with half or less the cylinders and displacement.
- With what we know about marine diesel parts sourcing (i.e. Tractor parts), its probably cheaper than you think.
- For the specific parts that are 'Marinized' like the water cooler and alternator, there is enough info out there to rebuild or buy new at reasonable prices, not the 'marine' mark-up...
- Most people should be able to remove a sailboat diesel using their boom as crane and some simple tools like a come-along.
- Tearing down an engine to its bare block requires very few specialized tools. Correct reassembly involves a few more than that, but most you can borrow from auto-parts stores these days, buy cheap used, or borrow from a motor head buddy.
- The boring and honing of cylinder walls and other machine time isn't as expensive as you might think. Add to that a marine diesel is significantly smaller than a V8 with half or less the cylinders and displacement.
- With what we know about marine diesel parts sourcing (i.e. Tractor parts), its probably cheaper than you think.
- For the specific parts that are 'Marinized' like the water cooler and alternator, there is enough info out there to rebuild or buy new at reasonable prices, not the 'marine' mark-up...
Thank you, I'm going to try flooding the engine with marvel for a few weeks before I take the head off. How complicated is the head removal? I haven't tackled a job like this since I was 21 yrs old on a Renault r10
I think 'flooding' will just waste a lot of the stuff. Getting it to where it's needed shouldn't require that. A few squirts through the injector or should work, if any such thing will.
I prefer PB Blaster. I think it works better for this kind of thing than Marvel.
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