Chemdawg
Petty Officer 2nd Class
- Joined
- Aug 31, 2013
- Messages
- 112
Hello everyone again... Well more questions here.... In an earlier post, I commented on the milky color of my oil. So here come my problems and questions..
1: 1987 3.0 Mercruiser with alpha 1 outdrive
2: No water in oil after running
3: Engine overheated during running because of a bad impeller, so I shut it down before it burned up
4: Replaced impeller and thermostat, and it ran great and cooled fine.
5: Checked oil before bringing it to lake, and still nice oil color
6: Checked oil after coming home, and noticed the tan milky color. But it's NOT over filled
7: Did a compression check on each cylinder and had (Left to Right) 110 80 80 110
So. With that being said, I was assuming it was a blown head gasket. No problem. I seen online and someone commented on my last post that you can pull off the valve cover and rotate the engine by hand till the #2 cylinder has both valves closed, and pull the plug out of #3. Introduce air into the cylinder, and you should have air coming out plug 3"s hole. I tried that, and I had light air coming out the far left plug, but nothing really out of #3. So I didn't think that was a very definitive test. So.... Drained all water out of engine and manifold. Blocked off the hose going to the manifold, and pumped air into the hose coming from the impeller. Air went in, and held. Even with the plugs out. When I opened up the water valve on the block, the air rushed out. So that tells me no cracked block.
I read the water in oil sticky posted by Don a while ago, and it the mercury bulletin in that post, stated something about water coming back in through the exhaust during hard deceleration. I'm not sure if this is the case at all. (prop exhaust, not through hull)
So with all of this info, does it still sound like there is an issue with my head gasket? I really don't want to pull it off and find out there was nothing wrong there. Should I pull the intake/exhaust off, and check to see that it's holding water?
What are my next steps?
Thank you all so much in advance
Pat Frailing
1: 1987 3.0 Mercruiser with alpha 1 outdrive
2: No water in oil after running
3: Engine overheated during running because of a bad impeller, so I shut it down before it burned up
4: Replaced impeller and thermostat, and it ran great and cooled fine.
5: Checked oil before bringing it to lake, and still nice oil color
6: Checked oil after coming home, and noticed the tan milky color. But it's NOT over filled
7: Did a compression check on each cylinder and had (Left to Right) 110 80 80 110
So. With that being said, I was assuming it was a blown head gasket. No problem. I seen online and someone commented on my last post that you can pull off the valve cover and rotate the engine by hand till the #2 cylinder has both valves closed, and pull the plug out of #3. Introduce air into the cylinder, and you should have air coming out plug 3"s hole. I tried that, and I had light air coming out the far left plug, but nothing really out of #3. So I didn't think that was a very definitive test. So.... Drained all water out of engine and manifold. Blocked off the hose going to the manifold, and pumped air into the hose coming from the impeller. Air went in, and held. Even with the plugs out. When I opened up the water valve on the block, the air rushed out. So that tells me no cracked block.
I read the water in oil sticky posted by Don a while ago, and it the mercury bulletin in that post, stated something about water coming back in through the exhaust during hard deceleration. I'm not sure if this is the case at all. (prop exhaust, not through hull)
So with all of this info, does it still sound like there is an issue with my head gasket? I really don't want to pull it off and find out there was nothing wrong there. Should I pull the intake/exhaust off, and check to see that it's holding water?
What are my next steps?
Thank you all so much in advance
Pat Frailing
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