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Coolant in cylinders

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SeaSprite195

Member
Hey guys,

Info: 1986 Mercruiser 170, 2 barrel carb.

After having my starter bind up and running through some diagnostics on it, I pulled the spark plugs and turned the starter over a few times only to find coolant spewing out of the holes like Old Faithful. Hopefully Thursday I will be pulling the rocker cover, intake manifold, exhaust manifold, and head and checking all of the gaskets for blow outs. Will also be checking the head for cracks and cylinder walls for cracks.

Any advice you can give to a guy who is just learning about engines on what I should be looking for, what to expect during the removal of all of these parts? Dad said that I wouldn't need to drain the oil. Also, needless to say but my coolant reservoir is bone dry. I'm worried I have a cracked block, but I tend to think the worst of things.

ANY tips, help, advice is greatly appreciated.
 
If so then I'm done with this boat lol.

As asked in the previous post, any advice on what to look for? "I think you have a cracked head" doesn't give me much on how to find the crack in the head.
 
I wouldn't throw the block away, just yet...
Is the cooling system a full fresh water coling system or half system? (In other words, are the exhaust manifolds cooled by engine coolant or raw water?)
If the exhaust manifolds (and spacer blocks if so equiped) are cooled by the engine coolant, they are most likely the source of your problem, and probably the only things (as well as the raw water cooled elbow(risers)) that need replaced.

If the engine was coverted from raw water cooled to fresh water at some point, the manifolds and spacers should have been repalced at that time... the coversion slows the corrossion rate, but if they were exposed to salt water and they already started to corrode, it's only a mater of time before they spring a leak, especailly around the gasket sealing areas. The walls between the coolant passages and the exhaust passages are pretty thin to begin with, and they are cast iron... localized pitting corrosion isn't a process that can be reversed.
 
He has a merc 4 cylinder the imfamous 170/470. It only came as a CLOSED COOLING system.

You ask what to do.... Find someone local to you with experiance with this motor and do some additional searching the topics here. There have been a few in the last month on this motor and subject.
 
Hey thanks guys for the advice.

Well, got the head off and #3 cylinder has a crack through the whole wall and block.

Time to part this SOB out. Anybody want anything?
 
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