water in crankcase

Riser gaskets, blown head gasket...........

Here is the list I found in the forums,I feel your pain. Dave.
leo0648
The PCM manual says the most common way to get water in the oil is a cracked exhaust manifold.
     Lets make a list of possibilities.

    1) Cracked exhaust manifold
    2) Cracked exhaust riser
    3) Exhaust riser gasket
    4) Cracked intake manifold
    5) Intake manifold gasket
    6) Cracked timing chain cover
    7) Timing chain cover gasket
    8) Cracked head
    9) Blown head gasket
   10) Cracked block

I'm pretty sure the even bank manifold is cracked. It drips when the engine is off. Very small amount. I don't get how exhaust cracked would do that, as stated above without getting water in the cylinders. No white smoke. I like that option, since its easiest, but I don't understand how that would work. Its a reverse rotater, so another engine is not an option for now. I think we'll pull the heads and start there. Any suggestions for testing these theories? I was thinking put water in the jacket without heads and see where the water goes. Same with the heads. We got a steal on this classic and got it titled and running (not as easy as it sounds), but we didn't plan to put a ton of cash into a block or heads.
Btw its a 79 sn. 350 omc powerplant.

good luck and keep us updated!

Start with a compression test, good compression will rule out the head gaskets and the must common block cracks from freezing. It's also quick and a relatively cheap tool to buy.

My buddy Steve and I fought this last year.His block was cracked under the cam hard to see until all the rotating assembly was removed.Hope yours is not so terminal as his was.We had to get another block which meant new pistons,rings,bearings.

Munday

crnsuperduty wrote: We did compression test a few cylinders before. They looked fine. It just runs so well, I couldn't convince myself to keep testing. I have a hard time believing someone would build an engine out of a junk block, but its starting to look that way.

Did you inspect the intake manifold for cracks? From what Ive read here, the area near the thermostat housing is one of the weaker areas.

Well, the heads pressure tested ok. So it seems we are down to block or intake. Dad says intake looks fine, but I haven't seen it yet. I have another intake to try. We are pulling the block out for disassembly and inspection tonight. I hope to find an obvious crack. Not sure if we'll fix it, or replace it. But I hope to at least find the problem.

Its an OMC chevy block. I didn't include that until about the 4th post. sorry.

I have not considered threaded bungs?   Honestly I don't really know what your talking about. I'm not in front of it right now. Let me know if you find the youtube.. or if anyone has pics of that.

Should have the pressure test results for the block today.

I'm hoping that would be picked up in pressure testing.

Block tested ok. I guess we are going to reassemble it with another intake. Still no idea what's wrong.....

Since your block is Chevrolet I offer no help. But I found the link to the YOU TUBE video.     Type in this: Ford 351 Windsor Small Block Engine - Water in Oil Mystery.    This shows the plug failure I spoke of.
Bob

Congrats

did you have the heads magnafluxed at a machine shop? also each bolt that goes into or near a water jacket area on a small block chev. should get ample sealant on the threads prior to incertion.
let me know if you are still stumped and i will ask my neighbor who owns a machine shop what he thinks?

Hooty222

Thanks for your post. I found water in my oil this past weekend. After some investigating, it turned out to be a toothpick size hole in one of the plugs the video speaks of. I am flushing all of the crud out now and hope to test this weekend. Hopefully nothing else was damaged.