Question: Do I have a cracked cylinder head?
08-01-2013 | 01:47 PM
#1
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From: NE Indiana
Question: Do I have a cracked cylinder head?
picture of milkshake on top of engine from one side only.
[ATTACH=CONFIG]505411[/ATTACH][ATTACH=CONFIG]505412[/ATTACH]
Ran my 272 for the forth time this summer testing and de-bugging. The third time we had some oil on top of the engine, this time was the most. I also ran it longer, 7/10 of an hour (which is a record for me so far!).
Anyways, the motor seems to run strong. The oil is Valvoline VR1 20w-50, not synthetic. Oil and motor have 3.7 total hours on the meter to include some hose testing and gauge testing. The last run was idle up to about 3500 rpm and I would say about 25 to 30 minutes was on plane time so 2000 to 3500. The milkshake is on the port motor, but only the port side of it. The other side is clean. The other breather hose is even dry, looks clean.
On the port side, you can see the shine inside the breather hose that runs up to the carb. You can see where this mixture ran down the side of the carburetor from collecting on the flame arrestor also. Some of it is pulled into the carb as you can see some buildup on the choke butterfly. Temp and oil pressure on this motor look fine also.
The oil in the pan is at the correct level and still looks new. Being non synthetic, I would think any water would mix in the heat and not resist changing as much as a synthetic would. I pulled the valve cover off and am not seeing anything. No tan underneath the cover, nothing on the fill cap. Maybe some of the oil laying in the valleys of the head has a "bit" of tan color, but it is hard to tell if it is just starting to get discolored due to use.
Pulled all four plugs on the head and they look the same and good.
What would cause oil/water to blow out of one valve cover and not the other? Need to do a compression test still.
I am thinking block or head gasket would effect the whole motor and the oil in the pan also. Intake leak into cylinder 1 or 7 would change that plug and again, effect all the oil. Can a head crack vent into the valve cover and push all the water right up the breather? The cylinders were all honed when apart with new rings put in, so wondering if they are not sealed well yet and creaking extra crank case pressure due to blow by. Would this pressure be enough to move enough air up the breather to keep steam out of the oil?
I have extra heads, so I could pull intake and put one on. Looking for ideas where to look.
Brian
[ATTACH=CONFIG]505411[/ATTACH][ATTACH=CONFIG]505412[/ATTACH]
Ran my 272 for the forth time this summer testing and de-bugging. The third time we had some oil on top of the engine, this time was the most. I also ran it longer, 7/10 of an hour (which is a record for me so far!).
Anyways, the motor seems to run strong. The oil is Valvoline VR1 20w-50, not synthetic. Oil and motor have 3.7 total hours on the meter to include some hose testing and gauge testing. The last run was idle up to about 3500 rpm and I would say about 25 to 30 minutes was on plane time so 2000 to 3500. The milkshake is on the port motor, but only the port side of it. The other side is clean. The other breather hose is even dry, looks clean.
On the port side, you can see the shine inside the breather hose that runs up to the carb. You can see where this mixture ran down the side of the carburetor from collecting on the flame arrestor also. Some of it is pulled into the carb as you can see some buildup on the choke butterfly. Temp and oil pressure on this motor look fine also.
The oil in the pan is at the correct level and still looks new. Being non synthetic, I would think any water would mix in the heat and not resist changing as much as a synthetic would. I pulled the valve cover off and am not seeing anything. No tan underneath the cover, nothing on the fill cap. Maybe some of the oil laying in the valleys of the head has a "bit" of tan color, but it is hard to tell if it is just starting to get discolored due to use.
Pulled all four plugs on the head and they look the same and good.
What would cause oil/water to blow out of one valve cover and not the other? Need to do a compression test still.
I am thinking block or head gasket would effect the whole motor and the oil in the pan also. Intake leak into cylinder 1 or 7 would change that plug and again, effect all the oil. Can a head crack vent into the valve cover and push all the water right up the breather? The cylinders were all honed when apart with new rings put in, so wondering if they are not sealed well yet and creaking extra crank case pressure due to blow by. Would this pressure be enough to move enough air up the breather to keep steam out of the oil?
I have extra heads, so I could pull intake and put one on. Looking for ideas where to look.
Brian
08-01-2013 | 05:20 PM
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seen lots of condensation in valve covers and under intakes on good motors. seems like cooler weather and cool engine makes it worse. also if it was a cracked water would mix with the oil and entire engine would be a milkshake. just my thoughts.
08-01-2013 | 07:18 PM
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From: NE Indiana
Yeah, that was my thoughts on the engine oil being clean, but wanted to ask for experienced opinions on here. So many here know way more than me.
Thinking about it, this is the engine that the temp only gets up to about 135 on the gauge. Other motor goes up to 155-160 and stays there. I just figured either my gauge or sending unit was off. But maybe it is just running cold? I figured next time we run it, I will put a longer hose on that breather and run it into a 2 liter standing next to the motor. That way the blow by will be collected and I can see exactly what is coming out of that valve cover.
I am going to run it again and see how it does. It does worry me after ruining both cranks last year due to water in the oil, but I think I have that issue behind me with the new manifolds, 4" risers and sealing the head bolts this time around. The oil and plugs really do seem fine.
We will see if anyone else here can chime in and help out.
Brian
Thinking about it, this is the engine that the temp only gets up to about 135 on the gauge. Other motor goes up to 155-160 and stays there. I just figured either my gauge or sending unit was off. But maybe it is just running cold? I figured next time we run it, I will put a longer hose on that breather and run it into a 2 liter standing next to the motor. That way the blow by will be collected and I can see exactly what is coming out of that valve cover.
I am going to run it again and see how it does. It does worry me after ruining both cranks last year due to water in the oil, but I think I have that issue behind me with the new manifolds, 4" risers and sealing the head bolts this time around. The oil and plugs really do seem fine.
We will see if anyone else here can chime in and help out.
Brian
08-01-2013 | 10:53 PM
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From: Between A Womans Leggs in IL
If the oil is clean then its condensation.....change the thermostat and get the oil temps up and it will go away..it will reall be worse on the colder running engine with the fall days we are having..especially last weekend..
08-06-2013 | 12:41 PM
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From: NE Indiana
pulled the thermostat and it was a 140 degree one. Not sure how I got that. I wonder if they sent the wrong one and I just installed it, never checked. Well, I guess the dash gauge was correct that it didn't go over 140. New one is in, hopefully will test again soon. Now I have to fire it up and see where the power steering is leaking from.
If problem gets better or goes away, I will make sure to update this thread and add some tag lines for future searches. Might be able to help someone else out also.
Brian
If problem gets better or goes away, I will make sure to update this thread and add some tag lines for future searches. Might be able to help someone else out also.
Brian
08-06-2013 | 06:21 PM
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From: Lake Winnipesaukee, NH
Hey, I just wanted to give you a heads up that I recently found a new discontinued power steering rebuild kit on E-bay. Short money, less that $30 if I remember right. And it solved a nasty leak in my bilge.
I found the part # in Mercruiser's parts list, they showed it as NLA. But I copied the # and googled it. Got the kit that way. I think the actuators are the same as on 60's era Chevy pickups and some years Corvettes. If you can't get a kit the main culprit in mine was a 50 cent o-ring on the shuttle valve.
I split the instructions between what the kit said and what the Merc drive manual said. I ended up needing some information from each.
Good luck, love the Fomulas they flatten the medium chop we see out here.
I found the part # in Mercruiser's parts list, they showed it as NLA. But I copied the # and googled it. Got the kit that way. I think the actuators are the same as on 60's era Chevy pickups and some years Corvettes. If you can't get a kit the main culprit in mine was a 50 cent o-ring on the shuttle valve.
I split the instructions between what the kit said and what the Merc drive manual said. I ended up needing some information from each.
Good luck, love the Fomulas they flatten the medium chop we see out here.
08-06-2013 | 11:13 PM
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From: NE Indiana
Hey, I just wanted to give you a heads up that I recently found a new discontinued power steering rebuild kit on E-bay. Short money, less that $30 if I remember right. And it solved a nasty leak in my bilge.
I found the part # in Mercruiser's parts list, they showed it as NLA. But I copied the # and googled it. Got the kit that way. I think the actuators are the same as on 60's era Chevy pickups and some years Corvettes. If you can't get a kit the main culprit in mine was a 50 cent o-ring on the shuttle valve.
I split the instructions between what the kit said and what the Merc drive manual said. I ended up needing some information from each.
Good luck, love the Fomulas they flatten the medium chop we see out here.
I found the part # in Mercruiser's parts list, they showed it as NLA. But I copied the # and googled it. Got the kit that way. I think the actuators are the same as on 60's era Chevy pickups and some years Corvettes. If you can't get a kit the main culprit in mine was a 50 cent o-ring on the shuttle valve.
I split the instructions between what the kit said and what the Merc drive manual said. I ended up needing some information from each.
Good luck, love the Fomulas they flatten the medium chop we see out here.
Brian
Last edited by befu; 08-06-2013 at 11:14 PM. Reason: It is late and I am an idiot!!!! big news there....
08-07-2013 | 02:28 PM
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From: NE Indiana
[ATTACH=CONFIG]505744[/ATTACH]
Each valve cover has a hose going up to the flame arrestor. The pic here shows a couple of them, but not perfect since flame arrestors are removed. The PCV valves are all empty, no check ball in them like in a car.
Going to try to take it out tomorrow and run it again.
Brian
Each valve cover has a hose going up to the flame arrestor. The pic here shows a couple of them, but not perfect since flame arrestors are removed. The PCV valves are all empty, no check ball in them like in a car.
Going to try to take it out tomorrow and run it again.
Brian
08-08-2013 | 09:44 PM
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From: NE Indiana
So ran the boat today after we put a 160 degree thermostat in it. Ran it around a bit testing it and then we pull into the sand bar. This time, the port motor did not have any liquid on top of it now. No oil or water mixture, so that was good news. But one of the guys noticed that the flame arrestor was not on the same and there was a 1/2" gap between the pcv hose end and the flame arrestor. Last time, the little tube was basically touching the flame arrestor side. So we relocate it and off we go.
We run around for about 1/2 hour and we go back to the sand bar. We raise the hatch again and this time there is that familiar puddle of oil on the port side of the intake on the port motor. But this time, it is all oil, no water at all. Not tan. Engine oil is still fine.
So I figure I am sucking oil out of the valve cover somehow, not sure. Next time we run it we will keep the hose a 1/2" away. But with the engine temp up, no issues with condensation.
We run around for about 1/2 hour and we go back to the sand bar. We raise the hatch again and this time there is that familiar puddle of oil on the port side of the intake on the port motor. But this time, it is all oil, no water at all. Not tan. Engine oil is still fine.
So I figure I am sucking oil out of the valve cover somehow, not sure. Next time we run it we will keep the hose a 1/2" away. But with the engine temp up, no issues with condensation.
