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post #1 of 7 Old 03-02-2010 Thread Starter
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Yanmar HydroLock

I'm looking to purchase my first Cruiser, an O'day 28. The survey came back good and it appeared I was getting a good deal based on the research I had done. When it came time to test the refitted Diesel, which was a 12 year old Yanmar 30hp (I know, lots of HP for this boat) with an SD20 Sail Drive we ran into problems. It appears that anti-freeze was pumped into the cylinders during winterization because they couldn't get the engine started. this is the way it was explained to me anyway. The owner, who appeared truly shocked, lowered the price again where it's almost ridiculous.
The way I look at it, I could spend about $4K getting this engine going and I would still be somewhat ahead of the game.
So my questions is - how bad is this? Should I run away and not look back or if it is Hydrolock due to coolant getting into the cylinders, is this repairable.
Thanks in advance.
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post #2 of 7 Old 03-02-2010
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It could cost a new engine at worst, that's a lot more than $4K. If coolant is in the cylinders then you could have a blown head gasket or a perforated exhaust/heat exchanger and connecting rod or rods could have been bent during the hydrolock. This engine will need a professional engineers survey prior to purchase or get the price reduced to replace it after purchase. Including parts and labor you could be looking at $10K to $12K minimum.
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post #3 of 7 Old 03-02-2010
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I'm a little confused. Did the owner say they "pumped" antifreeze into the cylinders, or while they were trying to start the engine water got into the cylinders from the exhaust manifold. In either case, if the engine has been sitting for awhile with either sea water or an antifreeze mixture the rings and cylinders are probably rusty and the engine will need to be rebuilt (if it's even worth rebuilding). If you want this boat then pay what it is worth without an engine and then install one. There are worse things than having a boat with a brand new engine. Good luck.

SV Laurie Anne

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post #4 of 7 Old 03-02-2010
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If the engine is hydrolocked with antifreeze or water, then there could be big problems. It is actually possible to do it with fuel as well but that usually means that you have other problems.

If it is antifreeze/water (which it probably is) you need to figure out how long it has been in there. As jrd22 pointed out, this will cause rust inside your cylinder which is not good. The other harder thing to figure out is whether a rod got bent. There are two ways that water can get into the cylinder, through the exhaust or headgasket. Did they crank the engine for a while before it stopped cranking? If so, it is likely that they overfilled the waterlift muffler and it ran back into the cylinder. That would not be as bad from a rust standpoint since the water was not sitting in the cylinder. If it wouldn't turn right from the start, there has been water in there quite a while and it will probably be pretty bad.

Regardless, if the engine is truly hydrolocked (have they actually tried to bar it over by hand or pulled an injector?) the head should come off and the cylinders, pistons, rings, and bottom end should be inspected. People have successfully brought an engine that was recently hydrolocked back to life without all of this but the engine is not nearly as good anymore.

I would either not purchase the boat until the owner gets the engine fixed or buy it at a price that reflects no engine. $4k might be reasonable if you were mechanically inclined and could do a lot of the work yourself (remember, your time has value too) but if you are going to have someone else do the work, it will probably get more expensive.
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post #5 of 7 Old 03-03-2010
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The only real answer is "IT DEPENDS". There isn't enough information in your post to say whether the $4K is a reasonable accommodation for the engine or not, or whether the engine is repairable or not.


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post #6 of 7 Old 03-13-2010
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If the liners are pitted they can be replaced, new pistons rings and rods if bent. If it has effected the bearings, then a major rebuild is in order.
The yanmar should have decompression levers that can be opened to blow the liquid out and allow the engine to spin. If it does not, then the rebuild is obviou$, but the total amount of $$ is not unless you consider worst case, or even a repower. The older yanmars may have parts availability issues. Mack Boring would be a good resource to call.

Cal 9.2 #19 SilverSwan
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post #7 of 7 Old 03-13-2010
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I would make an offer as if the engine needs replacement.Be firm he will cave. First the market sucks,and its hard enough to unload a good boat....Red

Red, 77 Jeanneau Gin Fizz 38
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