3.0L Mercruiser Alpha One Water in Oil

[kaeden1100]

That has a crack-like appearance.

That's the same thing I thought when I saw it, however after cleaning it up, it doesn't really look like it's a crack. I even took a file and a screwdriver and tried to kind of "dig" into it to see if I could see an actual crack but there's nothing. It almost looks like a protrusion (maybe from a poor cast?) than a crack. Either that or maybe once upon a time it was cracked and then filled? Let me ask you this..

I decided to go ahead and pull the head, just to double check the head gasket and to see if I could get a better look at the rest of the block. The head gasket was definitely blown. I couldn't get a picture good enough for it to show on camera, but you could clearly see scorching on the gasket between cylinders 3 and 4 I believe if I remember correctly. You could also tell by looking at the head that cylinder three had been running colder than the rest (presumably due to cold combustion from the water getting into the cylinder). Now, my question is, almost all of the head bolts were wet coming out except for the two or three on the right side of the block (if looking at it from the front of the motor). These bolts would've lined up almost perfectly with the freeze plugs on that side of the block. I was talking to my dad about it (who's worked on engines and such for most of his life) and he said that it's possible there may have been a crack at one time and the block was sealed, causing what should've been water jackets right there to no longer get water. This seem feasible to anyone? Honestly just trying to figure out if it's worth even putting back together or if you guys are almost positive there was/is still an issue with the block. Like I said, head gasket was obviously bad so that's what I was leaning towards for the whole water in the oil issue but maybe I'm wrong?

Thanks again for all the help so far!

 

[kaeden1100]

There is no water held in by the gasket. So no, it wasn't the gasket.

Run a wire brush on the block where all the rust is in the middle under the exhaust and intake ports. See if there's a crack there.

If you read my last post where I quoted achris, do you think it's possible it's just head gasket or likely still an issue with the block?

 

[AShipShow]

If your compression numbers looked healthy than I would say its not likely your issue. I would still put my money on either cracked manifold or block... You need to take the prior advice and pressure test your manifold to rule that out.

I almost hate to bring it up, but I HAVE heard of milky oil from a previous post that was a result of running the motor for short periods of time and the condensation buildup in the motor was enough to milkshake the oil... Not saying thats what the problem is, but if you do all you're testing and come to no obvious issues, there's always the possibility that could have been it.

Thinking as far as you've pulled the motor apart, you might as well pull it at this point.. may give you a better look at the block for potential cracks.

 

[Rick Stephens]

If you read my last post where I quoted achris, do you think it's possible it's just head gasket or likely still an issue with the block?

Blown head gasket can indicate all sorts of things. I'd take a different tack and clean everything up and reassemble with new head gaskets and start pressure testing. It is the only way to be sure. I had a motor full of water and got ahead of myself and tore it down. Once apart, impossible to pressure test. If you cannot pressure test, you can't be certain there ain't a crack somewhere.

When pressure testing, you can use a stethoscope to listen for where any leak is. The manifold, since it is off, can be tested separately off the motor - that's a good thing as it allows easier motor testing.

 

[kaeden1100]

Blown head gasket can indicate all sorts of things. I'd take a different tack and clean everything up and reassemble with new head gaskets and start pressure testing. It is the only way to be sure. I had a motor full of water and got ahead of myself and tore it down. Once apart, impossible to pressure test. If you cannot pressure test, you can't be certain there ain't a crack somewhere.

When pressure testing, you can use a stethoscope to listen for where any leak is. The manifold, since it is off, can be tested separately off the motor - that's a good thing as it allows easier motor testing.

Looks like everybody was right. I got the chance to run home from work and decided I'd clean that spot on the block up a little and take a better look at it. Sure enough it's a crack.

So my next question is this: Is there anyway to temporarily repair/patch this just to get me through the rest of this season? We've probably got 2 more good months of boating weather here, and it's gonna be a little bit before I can spend the money on a block, SO, with that being said, I'd be highly interested in trying to do something just to get me by until this winter when I can pull the motor out and start a rebuild with a fresh block. A buddy of mine who used to boat all the time said I could probably get away with JB Welding it and getting everything back together. Said he even had a buddy who did it and it ran for something like 5+ years like that. Again, not looking for a permanent solution just something to get me by.

 

[kaeden1100]

Ah, and here's a picture

 

[Rick Stephens]

Unfortunately, that particular crack won't put water in your oil. Yes, that particular crack can easily be patched. Your cooling system builds no pressure. However, you still need to pressure test to find out why your oil got water in it. To me, the pics of the manifold and exhaust don't show a bit of issue with the manifold. No rust streaks at all. That theory still needs testing. But IMHO, if you're hopin' the head gasket was the issue, then you still need to pressure test the block to know whether there are internal cracks and you can patch and run.

 

[kaeden1100]

Unfortunately, that particular crack won't put water in your oil. Yes, that particular crack can easily be patched. Your cooling system builds no pressure. However, you still need to pressure test to find out why your oil got water in it. To me, the pics of the manifold and exhaust don't show a bit of issue with the manifold. No rust streaks at all. That theory still needs testing. But IMHO, if you're hopin' the head gasket was the issue, then you still need to pressure test the block to know whether there are internal cracks and you can patch and run.

I gotcha. So is there anyway to “easily” test the block itself after I get the head back on without having to put the manifold back on or is pressure testing through the manifold the only way?

 

[Rick Stephens]

I gotcha. So is there anyway to “easily” test the block itself after I get the head back on without having to put the manifold back on or is pressure testing through the manifold the only way?

Piece of cake!

Head on, block the water line that goes to the manifold. Disconnect the water line on the port side that comes from the transom to the thermostat housing - that's the inbound line form the pump in the outdrive. Make up a replacement for that hose at the thermostat housing with a schrader valve and a gauge. Pump up to 15 pounds and see what you see, hear what you hear.

 

[kaeden1100]

Piece of cake!

Head on, block the water line that goes to the manifold. Disconnect the water line on the port side that comes from the transom to the thermostat housing - that's the inbound line form the pump in the outdrive. Make up a replacement for that hose at the thermostat housing with a schrader valve and a gauge. Pump up to 15 pounds and see what you see, hear what you hear.

Okay, cool. Sounds easy enough. Thank you again for all the help. One more question though. My replacement head gasket isnt supposed to be here until Friday. Do you think it'd be possible to lay the old head gasket down to test the block for now or do you think the compromised gasket is most likely to cause a "false positive" when looking for leaks.

 

[Rick Stephens]

Okay, cool. Sounds easy enough. Thank you again for all the help. One more question though. My replacement head gasket isnt supposed to be here until Friday. Do you think it'd be possible to lay the old head gasket down to test the block for now or do you think the compromised gasket is most likely to cause a "false positive" when looking for leaks.

Don't bother. Do it right friday. If the motor passes the pressure test you can start in on reassembling and going boating. Get the block surface and head CLEAN.

 

[Grub54891]

I'm with mad props thoughts. I personally ran mine just putzing around a few times. The oil did get milky. Thought I had an issue, but a good hard run clears it up. Every year for the last five years it happens. I simply run it hard once in awhile and put it away wet.

 

[kaeden1100]

I'm with mad props thoughts. I personally ran mine just putzing around a few times. The oil did get milky. Thought I had an issue, but a good hard run clears it up. Every year for the last five years it happens. I simply run it hard once in awhile and put it away wet.

So you think it's possible this could be something as simple as that? When I say milkshake I mean the oil ALMOST looked white this last time when I pulled the rocker cover. However it is worth mentioning that the day it happened(I assume because it was clean before I took it out that day) was on the 4th, and I was out from probably 12PM to about 10:30PM and honestly I was probably pretty hard on it the majority of the day. I know I was running it pretty hard trying to get back to the ramp pretty quick that night? You think running it that hard and then immediately shutting it off and pulling it out could've caused the moisture and such? Like I said, never thought to check the oil again later that night or the next morning, just checked it the following weekend when I was getting ready to take it out again and saw the dreaded milkshake again.

 

[kaeden1100]

Don't bother. Do it right friday. If the motor passes the pressure test you can start in on reassembling and going boating. Get the block surface and head CLEAN.

Sounds good. Just to be clear because I'm going to try "hopefully", fingers crossed, to get it back together and running (on muffs) Friday night. So... once I've got the head back on, rocker arms and pushrods on, and everythings torqued down, I should pressure test right? Listen for leaks around the block and head?

 

[Rick Stephens]

yah. 15# and see if it drops. If it does drop, then you're listening.

 

[Grub54891]

So you think it's possible this could be something as simple as that? When I say milkshake I mean the oil ALMOST looked white this last time when I pulled the rocker cover. However it is worth mentioning that the day it happened(I assume because it was clean before I took it out that day) was on the 4th, and I was out from probably 12PM to about 10:30PM and honestly I was probably pretty hard on it the majority of the day. I know I was running it pretty hard trying to get back to the ramp pretty quick that night? You think running it that hard and then immediately shutting it off and pulling it out could've caused the moisture and such? Like I said, never thought to check the oil again later that night or the next morning, just checked it the following weekend when I was getting ready to take it out again and saw the dreaded milkshake again.

Well, it actually sounds like you do have an issue. Dang.

 

[kaeden1100]

yah. 15# and see if it drops. If it does drop, then you're listening.

okay so long story short, it’s 4:30AM now. Got the motor completely back together tonight, and have literally spent the last 4-5 hours just trying to get it to start and I absolutely cannot figure out what I’m missing. I’ve got spark. Checked spark at ignition coil and each plug. Timing also appears to be correct although not sure how it ever would’ve gotten messed with in the first place. Air and Fuel.. I assume I’m getting. When I put it in neutral and try to prime it, or have someone help me do it, I can literally see the fuel squirting into the throttle plate/ down into the carb. Which, to me means the motor is getting fuel. Not sure what would be stopping it from making it to the cylinder if it makes it that far. Air is kind of a given as if the throttle body is opening then it should be getting air right? I have NO idea what else to check. It just cranks endlessly. Checked plugs. They smell a little gassy but aren’t wet like gas has actually touched them. Checked kill switch/lanyard, even jumped the wires, still nothing. I feel like I’ve got to be missing something here. This thing ran phenomenaly before I tore it apart, even with the milkshake oil. So something bizarre has happened between then and putting it back together and I CAN NOT figure it out.

any advice?

 

[Scott06]

Check that you have compression. It’s possible the valves are miss adjusted and cylinders are not building pressure due to valves being open.

other than that rotate the distributor while cranking to adjust timing slightly.

 

[achris]

If you didn't move the dissy during head removal, but did pull the leads off the cap, just check (and double check) you have the leads on the right places. Turn the engine until you have compression on #1 (pull plug out and check it with your finger!), then pull the cap off the dissy and look at the rotor, see where it's pointing, and make sure that lead goes to #1. Then, working CW, #3, then #4, then #2.

I know that sounds basic, but... southkogs

Chris.......

 

[kaeden1100]

If you didn't move the dissy during head removal, but did pull the leads off the cap, just check (and double check) you have the leads on the right places. Turn the engine until you have compression on #1 (pull plug out and check it with your finger!), then pull the cap off the dissy and look at the rotor, see where it's pointing, and make sure that lead goes to #1. Then, working CW, #3, then #4, then #2.

I know that sounds basic, but... southkogs

Chris.......

getting around to checking that now. It’s worth mentioning if I let it sit for probably 30 minutes or so then try to start it it cranks once then backfires through the exhaust (spits something out of the prop too) once, then endlessly cranks again