3.0 engine seized

evilwind1

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Hi all- I just got a 1988 Sunbird cuddy (18 ft) very reasonable. A relatively inexpensive ,entry level family boat with a nice all around layout. The hull,full canvas and trailer are in close to perfect condition. The outdrive seems to work okay (tilt/trim) works. i bought the boat from a co=worker who told me the boat ran before sitting for 3 years . When I got the boat home I tried to turn it over it wouldn't spin. I took out the starter and tried to move it by the flywheel with a large screwdriver (plugs out -deep creep in cylinders-Marvel in the crank) but still won't budge. I guess my next move will be to remove head a try the wood block on the piston with a maul routine. I'd rather not try to move it by the front crank bolt but I might try the pulley strap ratchet.
Any other suggestions or advice will be greatly appreciated-Thanks .sun4.jpgsun1.jpgsun2.jpg
 

evilwind1

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Re: 3.0 engine seized

Oh yeah-forgot to mention an important detail- engine had alot of water mix in with the oil-milky. Could have came in through bad head gasket? Elbow ? Hopefully not a cracked block. I think I'll pull off the head anyway.
 

fishrdan

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Re: 3.0 engine seized

Pull the outdrive and then see if the engine will spin, it could be a locked up drive...

(Edit for second post) Water in the oil, 3 years? The engine is probably rusted up solid inside. If it wasn't winterized before being layed up, the block is most likely cracked,,, water in the oil...
 

HT32BSX115

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Re: 3.0 engine seized

Oh yeah-forgot to mention an important detail- engine had alot of water mix in with the oil-milky. Could have came in through bad head gasket? Elbow ? Hopefully not a cracked block. I think I'll pull off the head anyway.

Howdy,


You should pressure check the cooling system before you pull the head (remove the manifold and riser though)


I would say you have a cracked block. You'll be replacing the engine, so pulling the drive is a good second step (after the pressure check) since you'll be pulling the engine anyway.


I just got a 1988 Sunbird cuddy (18 ft) very reasonable.
I hope you didn't pay a lot..... The long block engine will cost you around $2000 http://www.usengine.us/mercruiser.html


Cheers,


Rick
 

evilwind1

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Re: 3.0 engine seized

Thank you gentlemen, I think I'll be pulling the engine. I have a guy right up the block that has been doing boat motors
(" Elsasser engines") for over 30 years . Another option is a motor on Craigslist for $650-,local, that supposedly runs well.
If the block is still good I'll have him rebuild it. I paid $500- for the boat & trailer and seems like a worthwhile project since the gelcoat/hull/canvas/electric are all in excellent shape.
 

HT32BSX115

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Re: 3.0 engine seized

Unless he'll guarantee the block is NOT cracked, I would pressure check it first.
It's much easier to pump full of air with the heads, water pump, and intake manifold still bolted on.

It would be a real pain to rebuild the engine only to find that it's cracked internally.

A "craigslist" truck engine would run well....
 

evilwind1

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Re: 3.0 engine seized

Is there a thread on how to do a pressure check? I've never done one. Thanks.
 

HT32BSX115

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Re: 3.0 engine seized

Is there a thread on how to do a pressure check? I've never done one. Thanks.

Pretty simple actually.

Remove the exhaust manifolds and risers and close all the cooling sytsem openings with rubber stoppers, pieces of hose, etc....... so you can connect a piece of hose, valve and gage. connect the gage to one of the openings..... close off all the other ones except where you pump in the air.

Use whatever typical plumbing fittings and hose to connect it all together. Pressurize the block with an air compressor to about 15 PSI and close the valve.(turn off the compressor so you can listen for leaks)

If the gage stays at 15 PSI (or what ever pressure you pumped it up to) you have no leaks. If it's leaking, you should be able to hear it.
 

evilwind1

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Re: 3.0 engine seized

I'll give it a shot and post the outcome, thanks again.
 

Howard Sterndrive

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Re: 3.0 engine seized

Thank you gentlemen, I think I'll be pulling the engine. I have a guy right up the block that has been doing boat motors

as Fishrdan said:
pull the drive first then try turning the engine again. could be a seized gimbal bearing or upper drive unit.
don't shoot the horse because your wagon is stuck in the mud
 

seaboo

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Re: 3.0 engine seized

as Fishrdan said:
pull the drive first then try turning the engine again. could be a seized gimbal bearing or upper drive unit.
don't shoot the horse because your wagon is stuck in the mud

Or (god forbid) it would be a shame to build an engine, get it installed and find out you also have a bad outdrive also. If you are building an engine you probably want to replace the bellows and grease the Gimbal bearing so you KNOW all the (major) maintenance is done and out of the way.
 

fishrdan

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Re: 3.0 engine seized

And,,, if you are going to pull the engine, the drive needs to come off first anyway.
 

evilwind1

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Re: 3.0 engine seized

I pulled the outdrive (came off easily) and everything looks really good. Shaft turns and the u-joint coupler seems OK (from what I can tell) I'm going to do the pressure test as per the instructions and see if I have any leaks/cracks.
If no leaks do you think I should pull the head and try to move the pistons with a wood block and maul? The motor's been soaking in DeepCreep and MarvelMystery for almost 3 weeks,if it's gonna turn it should now-unless the crank it totally melded onto the bearings.
 

HT32BSX115

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Re: 3.0 engine seized

If no leaks do you think I should pull the head and try to move the pistons with a wood block and maul? The motor's been soaking in DeepCreep and MarvelMystery for almost 3 weeks,if it's gonna turn it should now-unless the crank it totally melded onto the bearings.

That would be my next step if it holds air pressure.
 

evilwind1

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Re: 3.0 engine seized

Should I check the cylinder PSI also and what should the compression be?
 

HT32BSX115

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Re: 3.0 engine seized

Should I check the cylinder PSI also and what should the compression be?

I wouldn't even worry about cyl compression until you free it up and determine that there's no cooling system leaks.
 

evilwind1

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Re: 3.0 engine seized

Right, no point in checking the comp. now. Being that the engine is completely degreased,no fluids and outdrive is off I'm just thinkin to pull it out, drop the pan and give it a thorough inspection before I bring it to the engine guy and have it magnafluxed. If this motor has no cracks or if it's just blown out freeze plugs/head gasket etc- I think it would be worth it to rebuild this block or get another because I could see the hull and trailer going for another 5-10 years of use. I think this is a 140 HP engine so it should move the boat nicely.
Thanks for the tips and advice!
 

evilwind1

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Re: 3.0 engine seized

Well, i started taking the of the hoses and some of the water inlets elbow etc-inside is full of rust and the elbow has a huge crack. I'm guessing that the boat was running when it cracked and there was a ton of smoke. Doesn't matter now the motor needs to come out and a new one put in. I'm gonna leave this for a winter project.Here's some pics.OMC 3.0 003.jpgOMC 3.0 002.jpgOMC 3.0 001.jpgOMC 3.0 003.jpg
What would cause that to crack?
 

HT32BSX115

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Re: 3.0 engine seized

That's a strange place for a riser to crack. There's usually not a lot of water up high. But it looks like a "freeze" crack.

No matter....as plugged up as the manifolds are,you might see the same rust in the block and head.....
 
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