what happened to my engine

[foresteronw]

My boat is a 21 foot Eurosport, OMC 5.7L. I took my engine out today for it's first trip this season. Took a little time to get it started, about 4 minutes or so. After that I let it run for about 7 to 10 minutes and then idled out. I kept it at idle and just creeped along for about ten minutes. I then decided to get it up on plane and cruise a little. I couldn't get the boat over 2700 RPMs. The engine ran really rough, brought the throttle back and it ran better at low rpms. Tried again and the same thing happend, this went on for about another four tries. I stopped the boat and checked the points they were good, all wired were connected (recent tune up). There were no obvious signs of anything. I decided to bring it back to the dock, when we pulled in, I again lifted to engine cover to take a look and now my entire engine was covered in what looked like coffee with a lot of cream (water oil mixture). Engine still ran fine at idle. Any ideas would help. Thanks.

 

[Derk138]

Re: what happened to my engine

It sounds like the engine block is cracked and the manafold. Did you protect your block this winter w/ anti-freeze? I'm assumeing that you live up north. Check your oil dipstick and see if the coffe like sludge is in the oil pan. That will be a sure sign of a crack in the block.

 

[foresteronw]

Re: what happened to my engine

yeah there is sludge in the oil pan too. Is this a sure sign that the block is cracked. You said the manifold too, which one? exhaust or intake?

 

[Derk138]

Re: what happened to my engine

I would think the exhaust, since you had the sludge on the engine,it must of spryed out to have cover the engine. I would say the block is cracked, sorry to say. I had the same problem a few years ago. It wasn't a cheep repair.

 

[Derk138]

Re: what happened to my engine

Oh, i forgot. The manafold can be fixed, chevy manfolds can be brased but Fords can not, they won't hold. Good luck

 

[DJ]

Re: what happened to my engine

foresteronw,<br /><br />If the manifold(s) were leaking, the water would get into the combustion chambers and potentially hydraulicly lock the engine. You would see evidence on the spark plugs. They would be real clean-just like brand new.<br /><br />Most likely your water leak is a cracked engine block, or if you are lucky, an intake manifold and/or gasket.<br /><br />I do not understand the comment about brazing manifolds. The manifolds are made by the marinizer, whether it be MerCruiser, Volvo, OMC, etc. They have nothing to do with the origin of the engine-Chev./Ford, etc.

 

[foresteronw]

Re: what happened to my engine

so do you think my best bet would be to take the intake manifold off and check that.

 

[foresteronw]

Re: what happened to my engine

something to add, my boat still idles fine.

 

[DJ]

Re: what happened to my engine

forester,<br /><br />Taking the intake off would be a good idea. <br /><br />You may find something.

 

[flashback]

Re: what happened to my engine

Djohns19 is on the right track, spend a few minutes and remove the intake and see what you can see.. more times than not the cracks will show up in the lifter valley somewhere.........

 

[foresteronw]

Re: what happened to my engine

I know i am dreaming, and with my luck this won't be it. If it is my intake manifold, were do I get a new one? I have been looking online and have not found any information no them for boats. Is this something that is interchangeable between cars and Marine. my engine is a 5.7 OMC can i put an auto intake on this.

 

[DJ]

Re: what happened to my engine

forester,<br /><br />Sometimes you can get lucky and a "hard" part such as an intake can be used from an automotive application.<br /><br />However, I do not think that is the failed part. More than likely the block is cracked. As mentioned, the cracks quite often show up in the lifter valley.

 

[foresteronw]

Re: what happened to my engine

will the cracks be obvious when i pull the intake off? if i don't see any are there any tricks to finding them?

 

[flashback]

Re: what happened to my engine

in most cases, they are quite easy to spot.........good luck..........

 

[karayj]

Re: what happened to my engine

ebay has a few manifolds for sale

 

[anesthes]

Re: what happened to my engine

Before you do anything, I'd do a compression and leak down test. <br /><br />If some cyls have water in them, or some are dead you know you have a problem. <br /><br />You could also have a head gasket probem. <br /><br />If your block is cracked, you can get another block from an automotive application. Just make sure you re-use your camshaft.. And ensure the block is the same C/R as the one you are replacing.

 

[Capt Ken]

Re: what happened to my engine

Lets clear the air on this one. It is the block that is cracked, not the intake manifold. You can remove the intake in order to possibly see the cracks in the valley of the block. Cracked exhaust manifolds won't put water back into the engine while running. Only when the engine is off will water leak back thru the cylinders into the crankcase. More than likely the manifolds are cracked also, just may not show up yet. Any way you look at it, not winterizing just costed you a wad. I would say in the very least, you're looking at a marine base engine and manifolds.